JP2021082796A - Laser device and laser system - Google Patents

Abstract

To provide a laser device and a laser system that make it possible to suppress a reduction in design flexibility.SOLUTION: A laser device 1 comprises: a heat generation part for emitting light and generating heat by receiving input of predetermined energy; a flow passage 13 through which a fluid flows to thereby cool the heat generation part; an input energy detection part 18 for detecting the input energy inputted into the heat generation part; an output energy detection part 14 for detecting output energy of the light emitted from the heat generation part; an upstream side temperature sensor 15 that detects a temperature of the fluid on an upstream end of a section, in which the heat generation part is cooled, of the flow passage 13; a downstream side temperature sensor 16 that detects a temperature of the fluid flowing on a downstream side of the flow passage 13 with respect to the heat generation part; and a calculation part 90. The calculation part 90 estimates a flow rate of the fluid flowing through the flow passage 13 by performing calculation based on a difference between the input energy and the output energy and a difference between the temperature detected by the downstream side temperature sensor 16 and the temperature detected by the upstream side temperature sensor 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to a laser device and a laser system, and specifically to a laser device and a laser system capable of cooling a heat generating portion.

As one of the laser devices, for example, as described in Patent Document 1 below, a laser oscillator for oscillating a laser beam is known to be cooled by cooling water. When the flow rate of the cooling water decreases in such a laser device, the temperature of a heat generating portion such as a laser oscillator may rise excessively, which may cause a malfunction. Therefore, it may be required to detect the flow rate of the cooling water. As a method of monitoring the flow rate of such cooling water, a method using a flow meter is known as described in Patent Document 2 below.

Japanese Unexamined Patent Publication No. 2006-054408 Japanese Unexamined Patent Publication No. 2018-098391

However, since most of the flowmeters need to be installed in the pipe through which the fluid flows, it is necessary to make the pipe in which the flowmeter is installed thick to some extent. In addition, some flow meters can be installed outside the piping, but when using such a flow meter, the flow rate tends to be difficult to measure properly depending on the material of the piping, so the material of the piping is specified. It is necessary to use the material of. As described above, when the flow meter is used to measure the flow rate of the cooling water, the degree of freedom in designing the laser device tends to decrease.

Therefore, an object of the present invention is to provide a laser device capable of suppressing a decrease in the degree of freedom in design and a laser system including the laser device.

In order to achieve the above object, the laser apparatus of the present invention has a heat generating portion that emits light and generates heat when a predetermined energy is input, a flow path through which fluid flows to cool the heat generating portion, and the heat generation. The input energy detection unit that detects the energy input to the unit as input energy, the output energy detection unit that detects the energy of the light emitted from the heat generation unit as output energy, and the heat generation unit in the flow path are cooled. An upstream temperature sensor that detects the temperature of the fluid at the upstream end of the section, a downstream temperature sensor that detects the temperature of the fluid at the downstream end of the section that cools the heat generating portion of the flow path, and a calculation unit. , The calculation unit is calculated based on the difference between the input energy and the output energy and the difference between the temperature detected by the downstream temperature sensor and the temperature detected by the upstream temperature sensor. It is characterized in that the flow rate of the fluid flowing through the flow path is estimated.

In a laser device having a portion where light of a predetermined energy is emitted by inputting a predetermined energy, the portion generally generates heat. When such a part is called a heat generating part, the flow rate of the fluid flowing through the flow path for cooling the heat generating part is the difference between the energy input to the heat generating part and the light energy output from the heat generating part, and the downstream of the heat generating part. The inventor has found that it depends on the difference between the temperature of the fluid flowing on the side and the temperature of the fluid flowing on the upstream side of the heat generating portion.

The laser device of the present invention includes an energy detection unit that detects energy input to the heat generating unit as input energy, and an energy detection unit that detects the energy of light emitted from the heat generating unit as output energy. Further, the laser device of the present invention has an upstream temperature sensor that detects the temperature of the fluid at the upstream end of the section that cools the heat generating portion of the flow path, and a fluid temperature at the downstream end of the section that cools the heat generating portion. It is equipped with a downstream temperature sensor for detection. Therefore, the calculation unit cools the heat generating unit by performing a calculation based on the difference between the input energy and the output energy and the difference between the temperature detected by the downstream temperature sensor and the temperature detected by the upstream temperature sensor. The flow rate of the fluid flowing through the flow path can be estimated.

By the way, as a method of measuring the flow rate of a fluid flowing through a flow path, there is a method of using a flow meter as in Patent Document 2. However, when using a flow meter, when arranging the flow meter in the pipe, it is necessary to make the pipe thick to some extent, and when arranging the flow meter on the pipe, the material of the pipe tends to be limited. Therefore, the degree of freedom in design tends to decrease. On the other hand, the temperature sensor that detects the temperature of the fluid can be arranged in a smaller space than the flow meter, and the temperature sensor can be arranged in the pipe without thickening the pipe. Further, since the temperature sensor can measure the heat of the fluid transmitted to the pipe, even when the temperature sensor is arranged on the pipe, the heat can be measured while being suppressed from being influenced by the material of the pipe. The laser apparatus of the present invention uses such a temperature sensor as a means for measuring the flow rate. Therefore, according to the laser apparatus of the present invention, it is possible to detect the flow rate while suppressing a decrease in the degree of freedom in designing the laser apparatus.

Further, the laser apparatus has, as the heat generating portion, an excitation light source for which a predetermined power is input to emit excitation light, and an amplification optical fiber for which the excitation light is incident and the active element is excited. The input energy detection unit detects the power input to the excitation light source as the input energy, and the output energy detection unit detects the energy of the light emitted from the amplification optical fiber as the output energy. When the fluid flows from the excitation light source side to the amplification optical fiber side, the upstream side temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path for cooling the excitation light source, and the above. The downstream temperature sensor detects the temperature of the fluid at the downstream end of the section of the flow path for cooling the amplification optical fiber, and when the fluid flows from the amplification optical fiber side to the excitation light source side, The upstream side temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path for cooling the amplification optical fiber, and the downstream side temperature sensor cools the excitation light source in the flow path. It is preferable to detect the temperature of the fluid at the downstream end of the section.

In this laser device, excitation light is generated by inputting a predetermined power to the excitation light source, and the excitation light emits light as output energy from the amplification optical fiber. In such a laser device, the difference between the power input to the excitation light source as input energy and the energy of light emitted from the amplification optical fiber as output energy is emitted from the input energy input to the laser device and the laser device. It is almost equal to the difference from the output energy. Laser light is generated in the amplification optical fiber. Further, in such a laser device, the calorific value in the excitation light source in which the excitation light is generated and the calorific value in the amplification optical fiber in which the laser light is generated are substantially equal to the total calorific value in the laser device. Therefore, when the entire laser device is considered as one heat generating portion, the amount of temperature change of the fluid by cooling the entire laser device is approximately the same as the amount of temperature change of the fluid by cooling the excitation light source and the amplification optical fiber. equal. Therefore, for example, when the fluid flows from the excitation light source side to the amplification optical fiber side, the temperature of the fluid at the upstream end of the section for cooling the excitation light source in the flow path and the section for cooling the amplification optical fiber in the flow path. The difference from the temperature of the fluid at the downstream end of the above can be regarded as the temperature change of the fluid when the entire laser device as the heat generating portion is cooled. Therefore, for example, when a fluid flows from the excitation light source side to the amplification optical fiber side, the difference between the power input to the excitation light source and the energy of the light emitted from the amplification optical fiber and the upstream end of the section for cooling the excitation light source. By performing a calculation based on the difference between the temperature of the fluid in the above and the temperature of the fluid at the downstream end of the section for cooling the amplification optical fiber, the flow rate of the fluid flowing through the flow path for cooling the laser device can be estimated more accurately. obtain.

Alternatively, the laser device has an excitation light source that emits excitation light when a predetermined power is input as the heat generating unit, and the input energy detection unit detects the power input to the excitation light source as the input energy. Then, the output energy detection unit detects the energy of the excitation light emitted from the excitation light source as the output energy, and the upstream temperature sensor is the upstream end of the section of the flow path for cooling the excitation light source. The downstream temperature sensor may detect the temperature of the fluid at the downstream end of the section of the flow path for cooling the excitation light source.

In this case, the difference between the power input to the excitation light source as the heat generating portion and the energy of the excitation light which is the light emitted from the excitation light source, the temperature of the fluid at the upstream end of the section for cooling the excitation light source, and the downstream of the section. By performing an operation based on the difference from the temperature of the fluid at the end, the flow rate of the fluid flowing in the section of the flow path for cooling the excitation light source can be estimated.

Alternatively, the laser apparatus has an amplification optical fiber in which excitation light is incident to excite an active element as the heat generating portion, and the input energy detection unit is the excitation that is incident on the amplification optical fiber. The light energy is detected as the input energy, the output energy detection unit detects the energy of the light emitted from the amplification optical fiber as the output energy, and the upstream temperature sensor detects the energy of the light emitted from the amplification optical fiber as the output energy. The temperature of the fluid at the upstream end of the section for cooling the amplification optical fiber is detected, and the downstream temperature sensor measures the temperature of the fluid at the downstream end of the section of the flow path for cooling the amplification optical fiber. It may be detected.

In this case, the difference between the energy of the excitation light incident on the amplification optical fiber as the heat generating portion and the energy of the light emitted from the amplification optical fiber and the upstream end of the section of the flow path for cooling the amplification optical fiber. By performing an operation based on the difference between the temperature of the fluid and the temperature of the fluid at the downstream end of the section, the flow rate of the fluid flowing in the section of the flow path for cooling the amplification optical fiber can be estimated.

Further, the calculation unit may perform a calculation of dividing the difference between the input energy and the output energy by the difference between the temperature detected by the downstream temperature sensor and the temperature detected by the upstream temperature sensor. preferable.

By performing such an operation by the arithmetic unit, the flow rate of the fluid flowing through the flow path for cooling the heat generating portion can be estimated more accurately.

ただし、上記式において、Ｌｂは、前記流体の流量［単位：Ｌ／ｍｉｎ］を示し、Ｐｄｉｓは、前記入力エネルギーと前記出力エネルギーとの差［単位：Ｗ（Ｊ／ｓ）］を示し、γｂは、前記流体の密度［単位：ｇ／ｃｍ³］を示し、Ｃｂは、前記流体の比熱［単位：Ｃａｌ／（ｇ×℃）］を示し、Ｔｏｕｔは、前記下流側温度センサで検出される前記流体の温度［単位：℃］を示し、Ｔｉｎは、前記上流側温度センサで検出される前記流体の温度［単位：℃］を示す。 In this case, it is preferable that the calculation unit performs a calculation based on the following formula.

However, in the above formula, Lb indicates the flow rate of the fluid [unit: L / min], Pdis indicates the difference between the input energy and the output energy [unit: W (J / s)], and γb. Indicates the density of the fluid [unit: g / cm ³ ], Cb indicates the specific heat of the fluid [unit: Cal / (g × ° C)], and Tout is detected by the downstream temperature sensor. The temperature [unit: ° C.] of the fluid is indicated, and Tin indicates the temperature [unit: ° C.] of the fluid detected by the upstream temperature sensor.

In this case, the fluid is water, and the calculation unit may perform a calculation based on the following equation.

Further, it is preferable that the difference between the input energy and the output energy is 100 W or more.

When the difference between the input energy and the output energy is 100 W or more, the flow rate of the fluid supplied to the laser device can be obtained more accurately.

Further, the laser system of the present invention includes a plurality of laser devices according to any one of the above, an optical combiner that combines the light emitted from each of the laser devices, and a delivery fiber that propagates the light emitted from the optical combiner. It is characterized in that it is provided with.

According to such a laser system, the flow rate of the cooling fluid flowing through each laser device 1 can be estimated for each laser device. Therefore, as compared with the case of monitoring the flow rate of the cooling fluid supplied to the entire laser system, it is possible to more appropriately estimate the malfunction of the laser system. Further, since the temperature sensor is used as a means for measuring the flow rate, a decrease in the degree of freedom in designing the laser system can be suppressed.

Further, the laser system further includes a control unit connected to the calculation unit of each of the plurality of laser devices and a warning unit connected to the control unit, and the control unit is provided in the calculation unit. The operation of the warning unit may be controlled based on the calculated difference between the flow rate of the fluid and the predetermined reference flow rate.

In this case, it is possible to more appropriately grasp whether or not a fluid having an appropriate flow rate is supplied to the laser apparatus.

As described above, according to the present invention, there is provided a laser device capable of suppressing a decrease in the degree of freedom in design and a laser system including the laser device.

It is a figure which conceptually shows the laser system which comprises the laser apparatus of this invention. It is a figure which shows schematicly the laser apparatus which concerns on 1st Embodiment. It is a top view which shows the optical module which comprises the laser apparatus. It is sectional drawing which is perpendicular to the longitudinal direction of the optical fiber for amplification shown in FIG. It is a block diagram which shows a part of the structure of a laser system. It is a figure which shows the laser apparatus which concerns on 2nd Embodiment from the same viewpoint as FIG. It is a figure which shows the laser apparatus which concerns on 3rd Embodiment from the same viewpoint as FIG.

Hereinafter, embodiments for carrying out the laser apparatus according to the present invention will be illustrated together with the accompanying drawings. The embodiments illustrated below are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. The present invention can be modified or improved from the following embodiments without departing from the spirit of the present invention. Further, in the present specification, the dimensions of each member may be exaggerated for ease of understanding.

(First Embodiment)
FIG. 1 is a diagram conceptually showing a laser system according to the first embodiment. As shown in FIG. 1, the laser system 100 mainly includes a plurality of laser devices 1, a plurality of optical fibers 106, an optical combiner 101, a delivery fiber 102, an output terminal 103, and a display unit 104. Prepare as.

Light having a predetermined wavelength is emitted from the plurality of laser devices 1.

The plurality of optical fibers 106 are connected to each laser device 1 and are provided as a main configuration with a core, a clad that surrounds the outer peripheral surface of the core without gaps, and a coating layer that covers the outer peripheral surface of the clad.

The delivery fiber 102 mainly includes a core, a clad that surrounds the outer peripheral surface of the core without gaps, and a coating layer that covers the outer peripheral surface of the clad, and emits light emitted from the laser device 1 of the laser system 100. Propagate toward the exit end. One end of the core of the delivery fiber 102 is optically coupled to one end of the core of the plurality of optical fibers 106 via an optical combiner 101.

The output end 103 includes the exit end of the laser system 100 and is connected to the other end of the delivery fiber 102. The output end 103 is formed of, for example, rectangular parallelepiped glass, and has a diameter larger than that of the delivery fiber 102. It should be noted that such an output end 103 does not necessarily have to be provided.

The display unit 104 is connected to each laser device 1 and performs a predetermined display based on a signal input from each laser device 1.

Next, the laser device 1 constituting the laser system 100 will be described in detail. Each of the plurality of laser devices 1 has the same configuration.

FIG. 2 is a diagram schematically showing the laser device 1 according to the first embodiment. As shown in FIG. 2, each laser device 1 of the laser system 100 includes an input wiring 17, an excitation light source 2, an optical combiner 3, an amplification optical fiber 5, an optical fiber 4, and a first FBG (Fiber Bragg Grating). ) 7, optical fiber 6, second FBG8, base 12, input energy detection unit 18, output energy detection unit 14, upstream side temperature sensor 15, downstream side temperature sensor 16, calculation unit 90, Is provided as the main configuration.

The input wiring 17 is connected to the excitation light source 2 and supplies a predetermined electric power to the excitation light source 2.

The excitation light source 2 includes a plurality of optical module units 10 from which excitation light is emitted, and a plurality of optical fibers 11 connected to each optical module unit. The optical fiber 11 is mainly provided with a core, a clad that surrounds the core without gaps, and a coating layer that covers the outer peripheral surface of the clad.

Each optical module unit 10 has the same configuration, and the electric power from the input wiring 17 is evenly distributed and input to each optical module unit 10. The optical module unit 10 includes a plurality of optical modules 20 having the same configuration.

FIG. 3 is a plan view showing the optical module 20. In FIG. 3, the optical path of light in the optical module 20 is shown by a broken line. As shown in FIG. 3, the optical module 20 includes a housing 21, an optical component described later housed in the housing 21, and a connector (not shown) for supplying power to some of the optical components. ..

The housing 21 is made of a metal material such as copper having high thermal conductivity, and includes a mount 24. A part of the mount 24 is formed in a stepped shape, and a part of the above optical components is mounted on the stepped part.

The optical components include a plurality of laser diodes 31, a plurality of first collimating lenses 36, a plurality of second collimating lenses 37, a plurality of mirrors 33, a first condensing lens 34, and a second condensing lens 35. , The optical fiber 29, and the like. One end of the optical fiber 29 is housed in the housing 21, and the other end is arranged outside the housing 21. Further, the number of the laser diode 31, the first collimating lens 36, the second collimating lens 37, and the mirror 33 is the same. That is, one first collimating lens 36, one second collimating lens 37, and one mirror 33 are provided for one laser diode 31.

The plurality of laser diodes 31 are arranged one by one on each step of the stepped portion of the mount 24. In the present embodiment, each laser diode 31 is an element having a Fabry-Perot structure in which a plurality of semiconductor layers including an active layer are laminated, and the stacking direction of the plurality of semiconductor layers is perpendicular to the installation surface. Arranged like this. Therefore, each laser diode 31 emits light whose fast axis is in the direction perpendicular to the installation surface and whose slow axis is in the direction parallel to the installation surface. For example, this light may be, for example, light having a wavelength in the 900 nm band.

The first collimating lens 36 is a lens that collimates the components in the fast axis direction of the light emitted from the laser diode 31.

The second collimating lens 37 is a lens that collimates the components in the slow axis direction of the light emitted from the laser diode 31.

Each mirror 33 is provided on the emission direction side of the light emitted from the corresponding laser diode 31. Therefore, each mirror 33 emits light from the laser diode 31 and reflects the light collimated by the collimating lenses 36 and 37 to change the propagation direction of the light. In the present embodiment, the mirror 33 changes the propagation direction of the light by 90 degrees.

The first condensing lens 34 is arranged on the optical path of each light reflected by the mirror 33 and turned 90 degrees, and condenses the light in the fast axis direction. The first condensing lens 34 may be, for example, a cylindrical lens.

The second condensing lens 35 is arranged on the optical path of each light reflected by the mirror 33 and turned 90 degrees, and condenses each light emitted from the first condensing lens 34 in the slow axis direction. The second condenser lens 35 may be, for example, a cylindrical lens.

The optical fiber 29 mainly includes a core, a clad that surrounds the outer peripheral surface of the core without gaps, and a coating layer that covers the outer peripheral surface of the clad, and the light emitted from the second condenser lens 35. It is located on the street. One end of the optical fiber 29 is positioned so that the light emitted from the second condenser lens 35 can enter the core of the optical fiber 29. As shown in FIG. 2, the optical fibers 29 of each optical module 20 are connected to the optical combiner 19, and are optically coupled to the optical fiber 11 via the optical combiner 19.

Next, the amplification optical fiber 5 of the laser device 1 will be described.

The amplification optical fiber 5 has an active element, and the active element is excited by excitation light. FIG. 4 is a cross-sectional view perpendicular to the longitudinal direction of such an amplification optical fiber 5. As shown in FIG. 4, the amplification optical fiber 5 includes a core 5a, an inner clad 5b that surrounds the outer peripheral surface of the core 5a without gaps, an outer clad 5c that covers the outer peripheral surface of the inner clad 5b, and an outer clad 5c. It is provided with a coating layer 5d to be coated as a main configuration, and has a so-called double clad structure. The refractive index of the inner clad 5b is lower than that of the core 5a, and the refractive index of the outer clad 5c is lower than that of the inner clad 5b.

As a material constituting the core 5a, for example, an element such as germanium (Ge) that increases the refractive index and an active element such as ytterbium (Yb) that is excited by the excitation light emitted from the excitation light source 2 are added. Ytterbium can be mentioned. Examples of such active elements include rare earth elements, and examples of rare earth elements include thulium (Tm), cerium (Ce), neodymium (Nd), europium (Eu), erbium (Er), and the like, in addition to the above Yb. Can be mentioned. Further, as the active element, bismuth (Bi) and the like can be mentioned in addition to the rare earth element.

Examples of the material constituting the inner clad 5b include pure quartz to which no dopant is added. An element such as fluorine (F) that lowers the refractive index may be added to the material of the inner clad 5b. The outer clad 5c is made of resin or quartz. Examples of such a resin include an ultraviolet curable resin and a thermosetting resin. Examples of quartz include quartz to which a dopant such as fluorine (F), which lowers the refractive index so as to have a lower refractive index than that of the inner clad 5b, is added. Examples of the material constituting the coating layer 5d include an ultraviolet curable resin and a thermosetting resin, and when the outer clad 5c is a resin, for example, an ultraviolet curable resin or a thermosetting resin different from the resin constituting the outer clad 5c. Is used.

As shown in FIG. 2, the optical fiber 4 is connected to one end of the amplification optical fiber 5 having the above configuration at one end. The optical fiber 4 includes a core to which no active element is added, an inner clad that surrounds the outer peripheral surface of the core without gaps, an outer clad that covers the outer peripheral surface of the inner clad, and a coating layer that covers the outer clad. Is provided as the main configuration. The core of the optical fiber 4 has substantially the same configuration as the core 5a of the optical fiber 5 for amplification except that no active element is added. The core of the optical fiber 4 is connected to the core 5a of the optical fiber 5 for amplification, and the inner clad of the optical fiber 4 is connected to the inner clad 5b of the optical fiber 5 for amplification. Further, on the other side of the optical fiber 4, the inner cladding of the optical fiber 4 is connected to each core of a plurality of optical fibers 11 of the excitation light source 2 via an optical combiner 3.

The optical fiber 6 is connected to the other end of the amplification optical fiber 5 at one end. The optical fiber 6 mainly includes a core to which no active element is added, a clad that surrounds the outer peripheral surface of the core without gaps, and a coating layer that covers the outer peripheral surface of the clad. The core of the optical fiber 6 is connected to the core 5a of the optical fiber 5 for amplification, and the clad of the optical fiber 6 is connected to the inner clad 5b of the optical fiber 5 for amplification. On the other hand, on the other side of the optical fiber 6, the core of the optical fiber 6 is connected to the core of the optical fiber 106.

The first FBG 7 is provided in the core of the optical fiber 4. The first FBG 7 is optically coupled to the core 5a of the amplification optical fiber 5 on one side of the amplification optical fiber 5. The first FBG 7 has a configuration in which a portion in which the refractive index is periodically increased along the longitudinal direction of the optical fiber 4 is repeated. By adjusting this period, at least a part of the light emitted by the active element of the excited optical fiber 5 for amplification is reflected. The reflectance of the first FBG 7 is higher than the reflectance of the second FBG 8 described later, and the light of a desired wavelength among the light emitted by the active element is reflected at, for example, 99% or more. The wavelength of the light reflected by the first FBG7 is, for example, 1070 nm when the active element is ytterbium as described above.

The second FBG 8 is provided in the core of the optical fiber 6. The second FBG 8 is optically coupled to the core 5a of the amplification optical fiber 5 on the other side of the amplification optical fiber 5. The second FBG 8 has a configuration in which a portion where the refractive index increases at regular intervals is repeated along the longitudinal direction of the optical fiber 6. The second FBG 8 is configured to reflect light having at least a part of the wavelengths of the light reflected by the first FBG 7 with a reflectance lower than that of the first FBG 7. For example, the second FBG 8 reflects light having at least a part of the wavelengths of the light reflected by the first FBG 7 with a reflectance of 5% to 50%.

The base 12 is a member on which the excitation light source 2 and the amplification optical fiber 5 are mounted, and is made of a material having high thermal conductivity. In this embodiment, the base 12 is made of a metal such as copper. Inside the base 12, a flow path 13 through which a cooling fluid for cooling the excitation light source 2 and the amplification optical fiber 5 flows is formed.

The flow path 13 is formed by a pipe exposed from the base 12 and a pipe formed inside the base 12. The flow path 13 includes a first section 13A located directly below the excitation light source 2 mounted on the base 12 and a second section 13B located directly below the amplification optical fiber 5 mounted on the base 12. I'm out. In FIG. 2, the piping of the flow path 13 formed inside the base 12 is shown by a broken line.

Further, as shown by the alternate long and short dash line in FIG. 3, in the present embodiment, the first section 13A is provided at a position where each optical module 20 overlaps with the optical module 20 when viewed in a plan view, and each optical module 20 is provided. It has a meandering trajectory just below. Specifically, in the first section 13A, a section formed along the direction in which each laser diode 31 is aligned at a position directly below each laser diode 31 and each mirror 33 at a position directly below each mirror 33. Includes sections formed along the alignment direction. When the first section 13A has such a trajectory, the total length of the first section 13A can be lengthened, and the cooling effect can be enhanced.

Further, as shown in FIG. 2, in the present embodiment, the second section 13B is provided at a position where it overlaps with at least a part of the amplification optical fiber 5 when viewed in a plan view, and is directly below the amplification optical fiber 5. It has a meandering trajectory. Since the second section 13B has such a trajectory, the total length of the second section 13B can be lengthened, and the cooling effect can be enhanced.

In the present embodiment, the cooling fluid is water, and the flow path 13 is formed so that the cooling water flows in the order of the first section 13A and the second section 13B.

Next, the output energy detection unit 14, the input energy detection unit 18, the upstream temperature sensor 15, and the downstream temperature sensor 16 will be described.

As shown in FIG. 2, the input energy detection unit 18 is provided in the input wiring 17 and is connected to the calculation unit 90. The input energy detection unit 18 detects the electric power input from the input wiring 17 to the excitation light source of the laser device 1 as the input energy Pin based on the current value in the input wiring 17 and the voltage value in the input wiring 17, and this electric power. The Pin data is output to the calculation unit 90.

The output energy detection unit 14 is provided in the optical fiber 6 and is connected to the calculation unit 90. In the present embodiment, the output energy detection unit 14 includes a photodiode, for example, an optical fiber 6 is provided based on Rayleigh scattering of light propagating in a portion of the optical fiber 6 where the output energy detection unit 14 is provided. The propagating light energy, that is, the light energy emitted from the amplification optical fiber 5, is detected as the output energy Pout. The output energy detection unit 14 outputs the data of the output energy Pout to the calculation unit 90.

In the present embodiment, the upstream temperature sensor 15 is provided slightly upstream of the first section 13A located directly below the excitation light source 2, and is connected to the calculation unit 90. Specifically, the upstream temperature sensor 15 is provided on the outer edge of the base 12 located slightly upstream of the upstream end 13Aa of the first section 13A. A pipe forming the flow path 13 is provided on the outside of the base 12. The upstream temperature sensor 15 is, for example, a thermistor, and may be mounted in the pipe or may be mounted on the pipe. The upstream temperature sensor 15 detects the temperature Tin of the cooling water immediately before cooling the excitation light source 2, and outputs the data of this temperature Tin to the calculation unit 90.

In the present embodiment, the downstream temperature sensor 16 is provided slightly downstream of the second section 13B located directly below the amplification optical fiber 5, and is connected to the calculation unit 90. Specifically, the downstream temperature sensor 16 is provided on the outer edge of the base 12 located slightly downstream of the downstream end 13Bb of the second section 13B. The downstream temperature sensor 16 is, for example, a thermistor, and may be mounted in the pipe outside the base 12 or may be mounted on the pipe outside the base 12. The downstream temperature sensor 16 detects the temperature Tout of the cooling water immediately after cooling the amplification optical fiber 5, and outputs the data of this temperature Tout to the calculation unit 90.

The calculation unit 90 calculates the flow rate of the cooling water flowing through the flow path 13 based on the data input from the output energy detection unit 14, the input energy detection unit 18, the upstream temperature sensor 15, and the downstream temperature sensor 16. To do. The calculation unit 90 is connected to the display unit 104, and outputs the calculated flow rate data to the display unit 104. Examples of such a calculation unit 90 include integrated circuits such as microcontrollers, ICs (Integrated Circuits), LSIs (Large-scale Integrated Circuits), and ASICs (Application Specific Integrated Circuits), and NC (Numerical Control) devices. be able to. Further, when the NC device is used, the calculation unit 90 may use a machine learning device or may not use a machine learning device.

Next, the operations of the laser device 1 and the laser system 100 will be described.

When electric power is supplied from the input wiring 17 to the excitation light source 2 of the laser device 1, the electric power is evenly distributed to each of the optical module units 10. Therefore, in each optical module unit 10, the distributed electric power is supplied to each optical module 20, and a part of the electric power is consumed by the laser diode 31 and converted into light.

The power Pin input from the input wiring 17 to the excitation light source 2 is detected by the input energy detection unit 18. Then, the input energy detection unit 18 outputs the data of the power Pin to the calculation unit 90.

Each light generated in each laser diode 31 of the optical module 20 is emitted from the laser diode 31 in a predetermined direction. Such light is, for example, light having a wavelength in the 900 nm band as described above.

The light emitted from each laser diode 31 is collimated in the fast axis direction and the slow axis direction by the collimating lenses 36 and 37, incident on the mirror 33, reflected by the mirror 33, and turned 90 degrees. The light reflected by each mirror 33 is incident on the first condensing lens 34, and is condensed in the fast axis direction by the first condensing lens 34. After being condensed by the first condenser lens 34, each of the above lights is incident on the second condenser lens 35 and is condensed in the slow axis direction by the second condenser lens 35. In this way, the light focused in the fast axis direction and the slow axis direction is incident on the core of the optical fiber 29 and propagates in the core of the optical fiber 29.

The light propagating in the core of each optical fiber 29 is combined in the optical combiner 19, and the combined light propagates in the core of the optical fiber 11.

In the other optical module units 10, similarly to the above, the light propagating in the core of each optical fiber 29 is combined in the optical combiner 19, and the combined light propagates in the core of the optical fiber 11. ..

As described above, the core of each optical fiber 11 is connected to the inner cladding of the optical fiber 4 via the optical combiner 3. Therefore, the light propagating in the core of each optical fiber 11 is combined by the optical combiner 3, and the combined light propagates in the inner cladding of the optical fiber 4.

Further, the light propagating in the inner clad of the optical fiber 4 is incident on the inner clad 5b of the optical fiber 5 for amplification. The light incident on the inner clad 5b mainly propagates through the inner clad 5b and passes through the core 5a. In this way, a part of the light incident on the core 5a is absorbed by the active element added to the core 5a, and as a result, the active element is excited. In this way, the light incident on the amplification optical fiber 5 becomes the excitation light, and the active element excited by the excitation light emits naturally emitted light having a specific wavelength. The naturally emitted light at this time is, for example, light having a certain wavelength band including a wavelength of 1070 nm when the active element is ytterbium. This naturally emitted light propagates through the core 5a of the amplification optical fiber 5, and light of a part of the wavelength is reflected by the first FBG7, and among the light reflected in this way, the light of the wavelength reflected by the second FBG8 is emitted. It is reflected by the second FBG8. In this way, the amplification optical fiber 5, the first FBG7, and the second FBG8 form a resonator, and light reciprocates in the resonator. Then, when the light reflected by the first FBG7 and the second FBG8 propagates through the core 5a of the amplification optical fiber 5, stimulated emission occurs and this light is amplified, and the gain and loss in the cavity become equal. It becomes a laser oscillation state. Then, a part of the light resonating between the first FBG7 and the second FBG8 passes through the second FBG8 and propagates in the core of the optical fiber 6 as laser light.

The output energy Pout of the light propagating in the core of the optical fiber 6 is detected by the output energy detection unit 14. Then, the output energy detection unit 14 outputs the data of the output energy Pout to the calculation unit 90.

As shown in FIG. 1, the laser system 100 includes a plurality of such laser devices 1, each laser device 1 has the same configuration, and the excitation light source 2 of each laser device 1 has the same amount of electric power. Is supplied. Therefore, the light emitted from each laser device 1 has substantially the same wavelength and energy. Therefore, each light propagating in the core of the optical fiber 6 propagates in the optical fiber 106 and then is combined in the optical combiner 101, and the combined light propagates in the core of the delivery fiber 102.

As described above, the output end 103 is connected to the end of the delivery fiber 102 on the side opposite to the optical combiner 101 side. Therefore, the light propagating through the delivery fiber 102 is incident on the output end 103. Further, as described above, the output end 103 has a diameter larger than that of the delivery fiber 102. Therefore, the light incident on the output end 103 propagates in the output end 103 while spreading, and is emitted from the exit surface of the output end 103. The light emitted from the output end 103 is collected by, for example, a processing head (not shown) and irradiates the object to be processed.

By the way, a part of the electric power Pin supplied to each laser diode 31 is not converted into light but is converted into heat. Therefore, when the laser device 1 operates, the temperature of each optical module 20 rises. In this way, the temperature of each optical module unit 10 composed of the plurality of optical modules 20 rises, and the temperature of the excitation light source 2 composed of the plurality of optical module units 10 rises. That is, in the laser device 1, the excitation light source 2 acts as a heat generating portion that generates heat by the input / output energy.

Further, when the active element of the amplification optical fiber 5 emits light, it releases heat. Therefore, when the laser device 1 operates, the temperature of the amplification optical fiber 5 rises due to the heat emitted by the active element. That is, in the laser device 1, the amplification optical fiber 5 acts as a heat generating portion that generates heat by the input / output energy.

As described above, the laser apparatus 1 is formed with a flow path 13 through which cooling water flows from the excitation light source 2 side to the amplification optical fiber 5 side. Therefore, the cooling water flowing through the flow path 13 first flows through the first section 13A. The first section 13A is located directly below the excitation light source 2 as described above, and the base 12 on which the excitation light source 2 is mounted is made of a metal such as copper having high thermal conductivity as described above. The heat generated by the excitation light source 2 is absorbed by the cooling water via the base 12. In this way, the excitation light source 2 is effectively cooled. On the other hand, the temperature of the cooling water immediately after flowing through the first section 13A rises as the cooling water absorbs the heat of the excitation light source 2. In this way, the first section 13A acts as a section of the flow path 13 for cooling the excitation light source 2.

The section for cooling the heat generating portion may be a section longer than the section located directly below the heat generating portion in the flow path 13, or may be a shorter section. That is, the "section for cooling the excitation light source 2" may be a section longer than the first section 13A or a section shorter than the first section 13A. In the present embodiment, the temperature is ± 0 with reference to the temperature of the cooling water at the upstream end 13Aa of the first section 13A, provided that the upstream temperature sensor 15 is not arranged downstream of the downstream temperature sensor 16. The section from the location of the flow path 13 where the temperature is 5.5 ° C to the location of the flow path 13 where the temperature is ± 0.5 ° C with reference to the temperature of the cooling water at the downstream end 13Ab of the first section 13A is ". It is referred to as a "section for cooling the excitation light source 2."

Next, the cooling water flows through the second section 13B. The second section 13B is located directly below the amplification optical fiber 5 as described above, and the base 12 on which the amplification optical fiber 5 is mounted is made of a metal such as copper having high thermal conductivity as described above. Therefore, the heat generated in the amplification optical fiber 5 is absorbed by the cooling water via the base 12. In this way, the amplification optical fiber 5 is effectively cooled. On the other hand, the temperature of the cooling water immediately after flowing through the second section 13B is higher than immediately after flowing through the first section 13A because the cooling water absorbs the heat of the amplification optical fiber 5. In this way, the second section 13B acts as a section of the flow path 13 for cooling the amplification optical fiber 5.

The "section for cooling the amplification optical fiber 5" may be a section longer than the second section 13B or a section shorter than the second section 13B. In the present embodiment, the temperature is ± 0 with reference to the temperature of the cooling water at the upstream end 13Ba of the second section 13B, provided that the downstream temperature sensor 16 is not arranged upstream of the upstream temperature sensor 15. The section from the location of the flow path 13 where the temperature is 5.5 ° C to the location of the flow path 13 where the temperature is ± 0.5 ° C with reference to the temperature of the cooling water at the downstream end 13Bb of the second section 13B is ". It is referred to as a "section for cooling the amplification optical fiber 5".

As described above, since the laser device 1 of the present embodiment is formed with the flow path 13 through which the cooling water flows, heat generating portions such as the excitation light source 2 and the amplification optical fiber 5 are generated as the laser device 1 operates. Even when heat is generated, such a heat-generating portion is cooled by the cooling water, and the temperature of the heat-generating portion is suppressed from rising excessively.

As described above, in the present embodiment, the upstream temperature sensor 15 is arranged at the outer edge of the base 12 located slightly upstream of the upstream end 13Aa of the first section 13A. As described above, the arrangement position of the upstream temperature sensor 15 in the present embodiment is the upstream end of the first section 13A on the condition that the upstream temperature sensor 15 is not arranged downstream of the downstream temperature sensor 16. This is the location of the flow path 13 that falls within the temperature range of ± 0.5 ° C. with respect to the temperature of 13Aa. If the temperature is measured at a position within such a temperature range, it can be regarded as the temperature of the cooling water immediately before cooling the excitation light source 2. Therefore, the arrangement position of the upstream temperature sensor 15 corresponds to the upstream end of the section for cooling the excitation light source 2 in the present embodiment. In this way, the temperature Tin of the cooling water immediately before cooling the excitation light source 2 is detected by the upstream temperature sensor 15, and the data of this temperature Tin is output to the calculation unit 90.

The arrangement position of the upstream temperature sensor 15 is not limited to the arrangement position shown in FIG. 2 as long as it falls within the above temperature range. For example, it may be on the upstream side or the downstream side from the position shown in FIG. Further, when the upstream temperature sensor 15 is arranged on the downstream side of the position of FIG. 2, the arrangement position of the upstream temperature sensor 15 may be the upstream end 13Aa of the first section 13A, as described above. As long as it falls within the temperature range, it may be on the downstream side of the end 13Aa, provided that the upstream temperature sensor 15 is not arranged downstream of the downstream temperature sensor 16.

As described above, in the present embodiment, the downstream temperature sensor 16 is arranged at the outer edge of the base 12 located slightly downstream of the downstream end 13Bb of the second section 13B. As described above, the arrangement position of the downstream temperature sensor 16 in the present embodiment is the downstream end of the second section 13B on the condition that the downstream temperature sensor 16 is not arranged upstream of the upstream temperature sensor 15. This is the location of the flow path 13 that falls within the temperature range of ± 0.5 ° C. with respect to the temperature of 13Bb. If the temperature is measured at a position within such a temperature range, it can be regarded as the temperature of the cooling water immediately after the amplification optical fiber 5 is cooled. Therefore, the arrangement position of the downstream temperature sensor 16 corresponds to the downstream end of the section for cooling the amplification optical fiber 5 in the present embodiment. In this way, the temperature Tout of the cooling water immediately after cooling the amplification optical fiber 5 is detected by the downstream temperature sensor 16, and the data of this temperature Tout is output to the calculation unit 90.

The arrangement position of the downstream temperature sensor 16 is not limited to the arrangement position shown in FIG. 2 as long as it falls within the above temperature range. For example, it may be on the downstream side or the upstream side from the position shown in FIG. Further, when the downstream temperature sensor 16 is arranged on the upstream side of the position of FIG. 2, the arrangement position of the downstream temperature sensor 16 may be the downstream end 13Bb of the second section 13B, as described above. As long as it falls within the temperature range, the downstream temperature sensor 16 may be on the upstream side of the end portion 13Bb, provided that the downstream temperature sensor 16 is not arranged upstream of the upstream temperature sensor 15.

ただし、上記式（１）において、Ｐｄｉｓは、入力エネルギーＰｉｎ［単位：Ｗ（Ｊ／ｓ）］と出力エネルギーＰｏｕｔ［単位：Ｗ（Ｊ／ｓ）］との差を示す。γｂは、流体の密度［単位：ｇ／ｃｍ³］を表す。Ｃｂは、流体の比熱［単位：Ｃａｌ／（ｇ×℃）］を示す。Ｔｏｕｔは、下流側温度センサで検出される流体の温度［単位：℃］を示す。Ｔｉｎは、上流側温度センサで検出される流体の温度［単位：℃］を示す。また、上記式（１）における数値０．０７は、比熱Ｃｂを単位（Ｊ／ｓ）に換算するための定数である。 By the way, in a laser device having a heat generating portion that emits light and generates heat when a predetermined energy is input, the flow rate of the fluid flowing through the flow path for cooling the heat generating portion is the energy input to the heat generating portion and the heat generating portion. The inventor has found that it depends on the difference from the energy of the light emitted from the heat generating portion and the difference between the temperature of the fluid flowing on the upstream side of the heat generating portion and the temperature of the fluid flowing on the downstream side of the heat generating portion. Specifically, the inventor has found that the flow rate is proportional to the difference in energy and inversely proportional to the difference in temperature of the fluid. For example, assuming that the flow rate of the fluid flowing through the flow path for cooling the heat generating portion is Lb [unit: L / min], the flow rate Lb can be estimated by the following equation (1).

However, in the above equation (1), Pdis indicates the difference between the input energy Pin [unit: W (J / s)] and the output energy Pout [unit: W (J / s)]. γb represents the density of the fluid [unit: g / cm ³ ]. Cb indicates the specific heat of the fluid [unit: Cal / (g × ° C.)]. Tout indicates the temperature [unit: ° C.] of the fluid detected by the downstream temperature sensor. Tin indicates the temperature [unit: ° C.] of the fluid detected by the upstream temperature sensor. Further, the numerical value 0.07 in the above formula (1) is a constant for converting the specific heat Cb into a unit (J / s).

Since the fluid is water in this embodiment, the values of γb and Cb in the above formula (1) are both 1. Therefore, in the present embodiment, the above formula (1) can be expressed by the following formula (2).

As described above, in the laser device 1 of the present embodiment, the excitation light source 2 that generates heat when power is input as input energy Pin and the excitation light is emitted, and the excitation light is incident and the light is emitted as output energy Pout. The amplification optical fiber 5 that generates heat by the operation is provided as a heat generating portion. In such a laser device 1, the difference between the power energy input to the excitation light source 2 and the energy of the light emitted from the amplification optical fiber 5 is the input energy input to the laser device 1 and the output energy output from the laser device. Is roughly equal to the difference between. Further, in such a laser device 1, the calorific value of the excitation light source 2 in which the excitation light is generated and the calorific value of the amplification optical fiber 5 in which the light is generated are approximately the total calorific value of the laser device 1. equal. Therefore, when the entire laser device 1 is considered as one heat generating portion, the amount of temperature change of the cooling water by cooling the entire laser device 1 is the cooling water by cooling the excitation light source 2 and the amplification optical fiber 5. It is almost equal to the amount of temperature change in. Therefore, the difference between the temperature of the cooling water at the upstream end of the section of the flow path 13 for cooling the excitation light source 2 and the temperature of the cooling water at the downstream end of the section of the flow path 13 for cooling the amplification optical fiber 5 is It can be regarded as a temperature change of the cooling water when the entire laser device 1 as a heat generating portion is cooled. Therefore, the difference between the power input to the excitation light source 2 and the energy of the light emitted from the amplification optical fiber 5, the temperature of the cooling water at the upstream end of the section for cooling the excitation light source 2, and the amplification optical fiber 5 are cooled. The flow rate of the cooling water flowing through the flow path 13 can be estimated more accurately by performing the calculation according to the above equation (2) based on the difference from the temperature of the cooling water at the downstream end of the section.

The calculation unit 90 is the difference between the input energy Pin and the output energy Pout based on the data of the input energy Pin input from the input energy detection unit 18 and the data of the output energy Pout input from the output energy detection unit 14. Calculate the value of Pdis. Further, the calculation unit 90 uses the above equation (2) based on the temperature data Tout input from the downstream temperature sensor 16, the temperature Tin data input from the upstream temperature sensor 15, and the Pdis data. Performs the calculation by. In this way, the flow rate Lb of the cooling water flowing through the flow path 13 for cooling the laser device 1 can be estimated.

The value of Pdis is preferably 100 W or more. When the value of Pdis is 100 W or more, the flow rate of the cooling water flowing through the flow path 13 of the laser device 1 can be estimated more accurately.

In the laser system 100 of the present embodiment, the suitability of the flow rate of the cooling water supplied to each laser device 1 is determined based on the data of the flow rate Lb calculated by the calculation unit 90 of each laser device 1. That is, the laser system 100 includes a display unit 104, and the display unit 104 determines whether or not the flow rate is appropriate.

FIG. 5 is a block diagram showing a part of the configuration of the laser system 100. As shown in FIG. 5, the display unit 104 of the laser system 100 includes a plurality of light emitting units 104L, a control unit 104C, and a storage unit 104M.

The plurality of light emitting units 104L are provided with one light emitting unit 104L corresponding to each laser device 1. Each of the plurality of light emitting units 104L is connected to the control unit 104C and emits light based on a signal input from the control unit 104C. As such a light emitting unit 104L, for example, a light emitting diode can be mentioned.

The storage unit 104M is connected to the control unit 104C and stores reference flow rate data indicating a reference flow rate, which is an appropriate flow rate of the cooling water flowing through the flow path 13. As such a storage unit 104M, for example, a semiconductor memory or the like may be used.

The control unit 104C is connected to the calculation unit 90 of each laser device 1. The control unit 104C determines the appropriateness of the flow rate of the fluid that cools the laser device 1 based on the signal input from the calculation unit 90 and the data read from the storage unit 104M, and if the flow rate is not appropriate, each light emitting unit The signal is output to 104L. Examples of such a control unit 104C include an integrated circuit such as a microcontroller, an IC (Integrated Circuit), an LSI (Large-scale Integrated Circuit), and an ASIC (Application Specific Integrated Circuit), or an NC (Numerical Control) device. be able to. Further, when the NC device is used, the control unit 104C may use a machine learning device or may not use a machine learning device.

The control unit 104C operates as follows, for example.

When the data of the flow rate Lb flowing through the flow path 13 is input from the calculation unit 90 of each laser device 1 to the control unit 104C, the control unit 104C reads out the reference flow rate data from the storage unit 104M, and the data of the flow rate Lb and the reference flow rate data To compare. Then, when the absolute value of the difference between the flow rate Lb data input from the calculation unit 90 of a certain laser device 1 and the reference flow rate data is larger than a predetermined value, the control unit 104C emits light corresponding to the laser device 1. A signal is output to unit 104L. In this way, the light emitting unit 104L emits light by this signal. Assuming that the absolute value of the difference between the flow rate Lb data input from the calculation unit 90 and the reference flow rate data is larger than a predetermined value, the flow rate of the fluid supplied to the laser device 1 is a constant amount larger than the reference flow rate. It is expected that it will fall below the limit. On the other hand, when the absolute value of the difference between the flow rate Lb data input from the other laser device 1 and the reference flow rate data is equal to or less than a predetermined value, the control unit 104C sends the light emitting unit 104L corresponding to the other laser device 1 to the light emitting unit 104L. No signal is output. That is, the light emitting unit 104L corresponding to the other laser device 1 does not emit light. Therefore, the user of the laser system 100 can appropriately grasp the laser device 1 to which the cooling water of an appropriate flow rate is not supplied among the plurality of laser devices 1. As described above, in the present embodiment, the control unit 104C controls the operation of the plurality of light emitting units 104L based on the difference between the flow rate Lb of the fluid calculated by the calculation unit 90 and the reference flow rate. Then, the plurality of light emitting units 104L function as warning units for notifying the user of the laser system 100 that there is a laser device 1 to which cooling water having an appropriate flow rate is not supplied.

The configuration and operation of the display unit 104 as described above are exemplary, and if the flow rate of the cooling water flowing through each laser device 1 can be grasped for each laser device 1, the configuration of the display unit 104 is Not limited to this, or it is not necessary to provide the display unit 104. Further, the control is not limited to the above.

According to the laser device 1 and the laser system 100 of the present embodiment as described above, the following effects can be obtained.

In a laser device having a heat generating part that generates heat when a predetermined energy is input and output, the flow rate of the fluid flowing through the flow path for cooling the heat generating part is the difference between the energy input to the heat generating part and the energy output from the heat generating part. It depends on the energy difference, which is the difference between the temperature of the fluid flowing on the downstream side of the heat generating portion and the temperature of the fluid flowing on the upstream side of the heat generating portion. Specifically, the flow rate is proportional to the value obtained by dividing the energy difference by the temperature difference, and can be estimated by the above equation (1). Especially when the fluid is water, it can be estimated by the above equation (2).

The laser device 1 of the present embodiment has an energy detection unit 14 that detects an input energy Pin input to an excitation light source 2 that is a heat generating unit, and an energy that detects an output energy Pout that is output from an amplification optical fiber 5 that is a heat generating unit. A detection unit 18 is provided. Further, the laser device 1 has an upstream temperature sensor 15 that detects the temperature Tin of the cooling water at the upstream end of the section that cools the excitation light source 2, and a cooling water temperature at the downstream end of the section that cools the amplification optical fiber 5. It is provided with a downstream temperature sensor 16 that detects Tout. Further, the calculation unit 90 has an energy difference Pdis between the input energy Pin detected by the output energy detection unit 14 and the output energy Pout detected by the output energy detection unit 14, and the temperature Tout and the upstream side detected by the downstream temperature sensor 16. Based on the temperature difference (Tout-Tin) from the temperature Tin detected by the side temperature sensor 15, the calculation according to the above equation (2) is performed. Therefore, according to the laser apparatus 1 of the present embodiment, the flow rate of the cooling water flowing through the flow path 13 can be estimated.

Further, when the entire laser device 1 is considered as one heat generating portion, the amount of temperature change of the cooling water by cooling the entire laser device 1 is the cooling water by cooling the excitation light source 2 and the amplification optical fiber 5. It is almost equal to the amount of temperature change in. Therefore, the temperature difference (Tout-Tin) between the temperature Tout of the cooling water at the downstream end of the section for cooling the amplification optical fiber 5 and the temperature Tin of the cooling water at the upstream end of the section for cooling the excitation light source 2 is heat generation. It can be regarded as a temperature change of the cooling water when the entire laser device 1 as a part is cooled. Therefore, it is obtained from the above equation (2) based on the energy difference Pdis between the input energy Pin input to the excitation light source 2 and the output energy Pout of the light emitted from the amplification optical fiber 5 and the temperature difference (Tout-Tin). The flow rate Lb to be generated can be a value closer to the actual flow rate of the cooling water flowing through the flow path 13. Thus, according to the laser apparatus 1 of the present embodiment, the flow rate of the cooling water can be estimated more accurately.

By the way, as a method of measuring the flow rate of a fluid flowing through a flow path, there is a method of using a flow meter as in Patent Document 2. However, when using a flow meter, when arranging the flow meter in the pipe, it is necessary to make the pipe thick to some extent, and when arranging the flow meter on the pipe, the material of the pipe tends to be limited. Therefore, the degree of freedom in design tends to decrease. On the other hand, the temperature sensor that detects the temperature of the fluid can be arranged in a smaller space than the flow meter, and the temperature sensor can be arranged in the pipe without thickening the pipe. obtain. In addition, since the temperature sensor can measure the heat of the fluid transmitted to the pipe, the temperature sensor is placed on the pipe while suppressing the influence on the material of the pipe even when it is placed on the pipe. And the heat can be measured. The laser device 1 of the present embodiment uses the upstream temperature sensor 15 and the downstream temperature sensor 16 as means for measuring the flow rate. Therefore, according to the laser device 1, the flow rate can be detected while suppressing a decrease in the degree of freedom in designing the laser device.

Further, since the laser system 100 of the present embodiment is composed of the laser device 1 capable of estimating the flow rate by the temperature sensor, the decrease in the degree of freedom in design can be suppressed. Further, since the laser system 100 includes a plurality of laser devices 1, it is possible to emit high-power light. Further, the laser system 100 includes a display unit 104 that emits light of the light emitting unit 104L corresponding to the laser device 1 based on the flow rate data from the calculation unit 90 of each laser device 1. Therefore, it is possible to grasp the appropriateness of the flow rate of the cooling water flowing through each laser device 1 for each laser device 1, and as compared with the case of monitoring the flow rate supplied to the entire laser system, a malfunction of the laser system or the like can be grasped. Can be estimated more appropriately.

In this embodiment, an example in which the cooling water flows through the flow path 13 from the excitation light source 2 side to the amplification optical fiber 5 side has been described, but the cooling water flows through the flow path 13 from the amplification optical fiber 5 side to the excitation light source 2. It may flow to the side. In this case, in the laser device 1, the upstream temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path 13 that cools the amplification optical fiber 5, and the downstream temperature sensor detects the temperature of the fluid in the flow path 13 as the excitation light source. It is configured to detect the temperature of the fluid at the downstream end of the section that cools 2.

(Second Embodiment)
Next, the second embodiment of the present invention will be described. The same or equivalent components as those in the first embodiment are designated by the same reference numerals and duplicated description will be omitted unless otherwise specified.

FIG. 6 is a diagram showing the laser apparatus according to the second embodiment from the same viewpoint as in FIG. As shown in FIG. 6, in the laser apparatus 1 according to the present embodiment, the output energy detection unit 14 and the downstream temperature sensor 16 are located at different positions from the output energy detection unit 14 and the downstream temperature sensor 16 of the first embodiment. It is mainly different from the laser apparatus 1 according to the first embodiment in that it is provided.

Specifically, in the first embodiment, the output energy detection unit 14 is provided in the optical fiber 6, whereas in the present embodiment, the output energy detection unit 14 is provided in the optical fiber 4. The output energy detection unit 14 is composed of, for example, a photodiode that detects Rayleigh scattering of excitation light propagating in a portion of the optical fiber 4 where the output energy detection unit 14 is provided. As described above, the excitation light emitted from each optical module unit 10 of the excitation light source 2 and combined with the optical combiner 3 propagates to the core of the optical fiber 4. Therefore, in the present embodiment, by providing the output energy detection unit 14 in the optical fiber 4, the energy of the excitation light emitted from the excitation light source 2 which is the heat generating unit is detected as the output energy Pout. The output energy detection unit 14 outputs the data of the output energy Pout to the calculation unit 90 as in the first embodiment.

Further, in the first embodiment, the downstream temperature sensor 16 is provided at the downstream end of the section for cooling the amplification optical fiber 5, whereas in the present embodiment, the downstream temperature sensor 16 is provided at the downstream end of the section for cooling the excitation light source 2. .. In the present embodiment, the downstream temperature sensor 16 is, for example, a thermistor, and is provided between the first section 13A and the second section 13B of the flow path 13. Specifically, for example, the downstream temperature sensor 16 is provided in the pipe slightly downstream of the downstream end 13Ab of the first section 13A. The downstream temperature sensor 16 detects the temperature Tout of the cooling water immediately after cooling the excitation light source 2 by being provided at such a position, and outputs the data of this temperature Tout to the calculation unit 90.

As in the first embodiment, the input energy detection unit 18 is provided in the input wiring 17, detects the input energy Pin input to the excitation light source 2, and outputs this data to the calculation unit 90. Further, as in the first embodiment, the upstream temperature sensor 15 is provided slightly upstream of the upstream end 13Aa of the first section 13A, and is the temperature of the cooling water immediately before cooling the excitation light source 2. The Tin data is detected and this data is output to the calculation unit 90.

As described above, in the laser apparatus 1 of the present embodiment, the excitation light source 2 is the heat generating portion to be detected, and the energy detection portions 14, 18 and the temperature sensors 15 and 16 are arranged on both sides of the excitation light source 2. To.

The calculation unit 90 calculates the energy Pdis consumed by the excitation light source 2 based on the value of the input energy Pin input to the excitation light source 2 and the value of the output energy Pout output from the excitation light source 2. Further, the calculation unit 90 uses the above formula based on the value of Pdis, the value of the temperature Tout of the cooling water immediately after cooling the excitation light source 2, and the value of the temperature Tin of the cooling water immediately before cooling the excitation light source 2. Perform the calculation according to (2).

By the calculation based on this equation (2), the flow rate Lb of the cooling water flowing through the section for cooling the excitation light source 2 can be estimated almost accurately. Then, for example, by multiplying this flow rate Lb by a predetermined correction coefficient, the flow rate of the cooling water flowing through the flow path 13 for cooling the laser device 1 can be estimated.

As in the first embodiment, the value of Pdis is preferably 100 W or more. When the value of Pdis is 100 W or more, the flow rate of the cooling water flowing through the first section 13A of the flow path 13 can be obtained more accurately.

Further, in the present embodiment, an example in which the cooling water flows through the flow path 13 from the excitation light source 2 side to the amplification optical fiber 5 side has been described, but the cooling water flows through the flow path 13 from the amplification optical fiber 5 side to the excitation light source 2. It may flow to the side.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. The same or equivalent components as those in the first embodiment are designated by the same reference numerals and duplicated description will be omitted unless otherwise specified.

FIG. 7 is a diagram showing the laser apparatus according to the third embodiment from the same viewpoint as in FIG. As shown in FIG. 7, in the laser apparatus 1 according to the present embodiment, the input energy detection unit 18 and the upstream temperature sensor 15 are located at different positions from the input energy detection unit 18 and the upstream temperature sensor 15 of the first embodiment. It is mainly different from the laser apparatus 1 according to the first embodiment in that it is provided.

Specifically, in the first embodiment, the input energy detection unit 18 is provided in the input wiring 17, whereas in the present embodiment, the input energy detection unit 18 is provided in the optical fiber 4. The input energy detection unit 18 is composed of, for example, a photodiode that detects Rayleigh scattering of excitation light propagating in a portion of the optical fiber 4 where the input energy detection unit 18 is provided. As described above, the excitation light emitted from each optical module unit 10 of the excitation light source 2 and combined with the optical combiner 3 propagates to the core of the optical fiber 4. Therefore, in the present embodiment, by providing the optical fiber 4 with the input energy detection unit 18, the energy of the excitation light incident on the amplification optical fiber 5 which is the heat generating unit is detected as the input energy Pin. The input energy detection unit 18 outputs the data of the input energy Pin to the calculation unit 90 as in the first embodiment.

Further, in the first embodiment, the upstream temperature sensor 15 is provided at the upstream end of the section for cooling the excitation light source 2, whereas in the present embodiment, the upstream temperature sensor 15 is a section for cooling the amplification optical fiber 5. It is installed at the upstream end of. In the present embodiment, the upstream temperature sensor 15 is, for example, a thermistor, and is provided in a portion of the flow path 13 between the first section 13A and the second section 13B. Specifically, for example, it is provided inside the base 12 slightly upstream of the upstream end 13Ba of the second section 13B. The upstream temperature sensor 15 detects the temperature Tin of the cooling water immediately before cooling the amplification optical fiber 5 by being provided at such a position, and outputs the data of this temperature Tin to the calculation unit 90.

As in the first embodiment, the output energy detection unit 14 is provided in the optical fiber 6, detects the energy of the light emitted from the amplification optical fiber 5 as the output energy Pout, and transmits this data to the calculation unit 90. Output. Further, as in the first embodiment, the downstream temperature sensor 16 is provided slightly downstream of the downstream end 13Bb of the second section 13B, and is the cooling water immediately after cooling the amplification optical fiber 5. The temperature Tout is detected and this data is output to the calculation unit 90.

As described above, in the laser apparatus 1 of the present embodiment, the amplification optical fiber 5 is the heat generating portion to be detected, and the energy detection portions 14, 18 and the temperature sensor 15 are located on both sides of the amplification optical fiber 5. 16 is arranged.

The calculation unit 90 calculates the energy Pdis consumed by the amplification optical fiber 5 based on the value of the input energy Pin input to the amplification optical fiber 5 and the value of the output energy Pout output from the amplification optical fiber 5. To do. Further, the calculation unit 90 sets the Pdis value, the temperature Tout value of the cooling water immediately after cooling the amplification optical fiber 5, and the cooling water temperature Tin value immediately before cooling the amplification optical fiber 5. Based on this, the calculation according to the above equation (2) is performed.

By the calculation based on this equation (2), the flow rate Lb of the cooling water flowing through the section for cooling the amplification optical fiber 5 can be estimated almost accurately. Then, for example, by multiplying this flow rate Lb by a predetermined correction coefficient, the flow rate of the cooling water flowing through the flow path 13 for cooling the laser device 1 can be estimated.

As in the first embodiment, the value of Pdis is preferably 100 W or more. When the value of Pdis is 100 W or more, the flow rate of the cooling water flowing through the second section 13B of the flow path 13 can be obtained more accurately.

Further, in the present embodiment, an example in which the cooling water flows through the flow path 13 from the excitation light source 2 side to the amplification optical fiber 5 side has been described, but the cooling water flows through the flow path 13 from the amplification optical fiber 5 side to the excitation light source 2. It may flow to the side.

Although the present invention has been described above by taking the above-described embodiment as an example, the present invention is not limited thereto.

あるいは、エチレングリコールと水との混合液を流体として用いてもよい。 For example, in the above-described embodiment, the example in which the fluid flowing through the flow path 13 is water has been described, but the present invention is not limited to this. That is, the fluid flowing through the flow path 13 may be, for example, ethylene glycol. In this case, since the density γb of ethylene glycol is 1.11 (g / cm ³ ) and the specific heat Cb is 0.57 (Cal / g ° C.), the flow rate of the fluid flowing through the flow path for cooling the heat generating portion. Lb can be calculated by the following equation (3).

Alternatively, a mixed solution of ethylene glycol and water may be used as the fluid.

Further, in the above-described embodiment, an example of detecting the energy of light based on Rayleigh scattering has been described, but the present invention is not limited to this. For example, in the first embodiment, a structure such as a clad mode stripper is provided on a portion of the optical fiber 6 opposite to the amplification optical fiber 5 side with respect to the second FBG 8, and the light leaked from the optical fiber 6 is emitted by this structure. A photodiode or the like to be detected may be used as an input energy detection unit.

Further, in the above-described first embodiment, an example will be described in which the excitation light source 2 and the amplification optical fiber 5 are used as heat generating portions, and energy detecting portions 14, 18 and temperature sensors 15 and 16 are provided on both sides of the heat generating portion. did. That is, in the first embodiment, the input energy detection unit 18 is provided so as to detect the electric power input to the excitation light source 2, and the output energy detection unit 14 is provided so as to detect the energy of the light output from the amplification optical fiber 5. An upstream temperature sensor 15 was provided on the upstream side of the excitation light source 2, and a downstream temperature sensor 16 was provided on the downstream side of the amplification optical fiber 5. Further, in the second embodiment described above, an example has been described in which the excitation light source 2 is used as a heat generating portion, and the energy detecting portions 14 and 18 and the temperature sensors 15 and 16 are provided on both sides of the heat generating portion. That is, in the second embodiment, the input energy detection unit 18 is provided so as to detect the power input to the excitation light source 2, and the output energy detection unit 14 is provided so as to detect the energy of the excitation light output from the excitation light source. An upstream temperature sensor 15 was provided on the upstream side of the excitation light source 2, and a downstream temperature sensor 16 was provided on the downstream side of the excitation light source 2. Further, in the third embodiment described above, an example has been described in which the amplification optical fiber 5 is used as a heat generating portion, and the energy detecting portions 14 and 18 and the temperature sensors 15 and 16 are provided on both sides of the heat generating portion. That is, in the third embodiment, the input energy detection unit 18 is provided so as to detect the energy of the excitation light input to the amplification optical fiber 5, and the light energy output from the amplification optical fiber 5 is detected. An energy detection unit 14 is provided, an upstream temperature sensor 15 is provided on the upstream side of the amplification optical fiber 5, and a downstream temperature sensor 16 is provided on the downstream side of the amplification optical fiber 5.

However, if a predetermined member of the laser device 1 other than the excitation light source 2 and the amplification optical fiber 5 generates heat due to the input and output of predetermined energy, the energy detection units 14 and 18 and the temperature sensors are provided on both sides of the member. 15, 16 may be provided. That is, an input energy detection unit 18 is provided to detect the energy input to the member, an output energy detection unit 14 is provided to detect the energy output from the member, and the output energy detection unit 14 is provided on the upstream side of the member in the flow path 13. An upstream temperature sensor 15 may be provided, and a downstream temperature sensor 16 may be provided on the downstream side of this member in the flow path 13. With such a configuration, the flow rate of the fluid flowing through the section of the flow path 13 for cooling this member can be estimated almost accurately. Further, the flow rate of the fluid flowing through the flow path 13 can be estimated by multiplying this flow rate by, for example, a predetermined correction coefficient. Even in this case, the calorific value of the predetermined member is preferably 100 W or more.

Further, the loci of the flow path 13 shown in FIGS. 2, 3, 6, and 7 are exemplary, and the flow path 13 is formed so as to cool the heat generating portion of the laser device 1. If so, the locus of the flow path 13 can be changed as appropriate.

The number of laser devices 1 shown in FIG. 1, the number of optical module units 10 shown in FIGS. 2, 6 and 7, and the number of laser diodes 31 as light emitting elements shown in FIG. 3 are exemplary. It is, and is not limited to these numbers.

Further, in the above embodiment, an example in which the control unit 104C emits light from the light emitting unit 104L has been described. However, for example, when the absolute value of the difference between the flow rate Lb data input from the calculation unit 90 of a certain laser device 1 and the reference flow rate data is larger than a predetermined value, the control unit 104C powers the laser device 1. The output of the laser beam from the laser device 1 may be stopped by stopping the supply of the laser beam.

Further, in the above embodiment, an example in which the warning unit is composed of the light emitting unit 104L provided corresponding to each of the plurality of laser devices 1 has been described, but the configuration of the warning unit is not limited to this. For example, the warning unit may be a sounding unit that emits a predetermined warning sound provided corresponding to each of the plurality of laser devices 1. Alternatively, one light emitting unit or sounding unit connected to each of the plurality of laser devices 1 may be used as a warning unit.

Further, the control unit 104C may operate the warning unit when there is at least one laser device 1 in which the absolute value of the difference between the flow rate Lb data and the reference flow rate data is larger than a predetermined value. With such a warning unit, it is possible to more appropriately grasp whether or not a fluid having an appropriate flow rate is supplied to the laser apparatus.

According to the present invention, a laser device and a laser system capable of suppressing a decrease in the degree of freedom in design are provided, and can be used in a field such as laser processing.

1 ... Laser device 2 ... Excitation light source (heat generating part)
5 ... Amplification optical fiber (heat generating part)
10 ... Optical module unit 13 ... Flow path 13A ... First section 13B ... Second section 14 ... Output energy detection unit 15 ... Upstream side temperature sensor 16 ... Downstream side temperature Sensor 18 ... Input energy detector 31 ... Laser diode 31 (light emitting element)
100 ... Laser system 104 ... Display

Claims (10)

A heat-generating part that emits light and generates heat when a predetermined energy is input,
A flow path through which a fluid flows and cools the heat generating portion,
An input energy detection unit that detects the energy input to the heat generating unit as input energy,
An output energy detection unit that detects the energy of the light emitted from the heat generating unit as output energy,
An upstream temperature sensor that detects the temperature of the fluid at the upstream end of the section of the flow path that cools the heat generating portion, and
A downstream temperature sensor that detects the temperature of the fluid at the downstream end of the section of the flow path that cools the heat generating portion, and
Computational unit and
With
The calculation unit calculates the flow path based on the difference between the input energy and the output energy and the difference between the temperature detected by the downstream temperature sensor and the temperature detected by the upstream temperature sensor. A laser device for estimating the flow rate of the fluid flowing through the surface. The heating unit includes an excitation light source to which a predetermined electric power is input and an excitation light is emitted, and an amplification optical fiber in which the excitation light is incident to excite an active element.
The input energy detection unit detects the electric power input to the excitation light source as the input energy, and then detects the power.
The output energy detection unit detects the energy of the light emitted from the amplification optical fiber as the output energy.
When the fluid flows from the excitation light source side to the amplification optical fiber side, the upstream temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path for cooling the excitation light source, and the temperature of the fluid is detected. The downstream temperature sensor detects the temperature of the fluid at the downstream end of the section of the flow path that cools the amplification optical fiber.
When the fluid flows from the amplification optical fiber side to the excitation light source side, the upstream side temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path for cooling the amplification optical fiber. The laser device according to claim 1, wherein the downstream temperature sensor detects the temperature of the fluid at the downstream end of the section of the flow path for cooling the excitation light source. It has an excitation light source that emits excitation light when a predetermined electric power is input as the heat generating portion.
The input energy detection unit detects the electric power input to the excitation light source as the input energy, and then detects the power.
The output energy detection unit detects the energy of the excitation light emitted from the excitation light source as the output energy.
The upstream temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path that cools the excitation light source.
The laser device according to claim 1, wherein the downstream temperature sensor detects the temperature of the fluid at the downstream end of the section of the flow path that cools the excitation light source. An amplification optical fiber in which excitation light is incident to excite active elements is provided as the heat generating portion.
The input energy detection unit detects the energy of the excitation light incident on the amplification optical fiber as the input energy.
The output energy detection unit detects the energy of the light emitted from the amplification optical fiber as the output energy, and then detects it.
The upstream temperature sensor detects the temperature of the fluid at the upstream end of the section of the flow path for cooling the amplification optical fiber.
The laser device according to claim 1, wherein the downstream temperature sensor detects the temperature of the fluid at the downstream end of the section of the flow path for cooling the amplification optical fiber. The calculation unit is characterized in that it performs a calculation of dividing the difference between the input energy and the output energy by the difference between the temperature detected by the downstream temperature sensor and the temperature detected by the upstream temperature sensor. The laser device according to any one of claims 1 to 4. The laser device according to claim 4, wherein the calculation unit performs a calculation based on the following formula.

However, in the above formula, Lb indicates the flow rate of the fluid [unit: L / min], Pdis indicates the difference between the input energy and the output energy [unit: W (J / s)], and γb. Indicates the density of the fluid [unit: g / cm ³ ], Cb indicates the specific heat of the fluid [unit: Cal / (g × ° C)], and Tout is detected by the downstream temperature sensor. The temperature [unit: ° C.] of the fluid is indicated, and Tin indicates the temperature [unit: ° C.] of the fluid detected by the upstream temperature sensor. The fluid is water
The laser device according to claim 5, wherein the calculation unit performs a calculation based on the following formula.

The laser device according to any one of claims 1 to 7, wherein the difference between the input energy and the output energy is 100 W or more. The laser apparatus according to any one of claims 1 to 8.
An optical combiner that combines the light emitted from each of the laser devices,
A delivery fiber that propagates the light emitted from the optical combiner,
A laser system characterized by being equipped with. A control unit connected to each of the calculation units of the plurality of laser devices,
A warning unit connected to the control unit and
With more
The laser system according to claim 9, wherein the control unit controls the operation of the warning unit based on the difference between the flow rate of the fluid calculated by the calculation unit and a predetermined reference flow rate.

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