KR20240118280A - Multi-channel optical power meter having optical wave filter - Google Patents

Abstract

We present a multi-channel optical power meter that effectively responds to the recent explosion of optical communication systems by miniaturizing it and includes an optical wavelength filter to sufficiently satisfy the characteristics required for optical communication. The power meter includes an optical splitter that separates the input optical signal according to its wavelength, a filter element that blocks and adjusts the optical power caused by the optical signal that has passed through the optical splitter, and multiple optical switches that open and close the optical signal that has passed through the filter element. Includes.

Description

Multi-channel optical power meter having optical wave filter}

The present invention relates to an optical power meter, and more specifically, to a multi-channel optical power meter that detects wavelengths and includes an optical wavelength filter that appropriately adjusts the intensity of optical signal power.

Wireless communication is developing into the Internet of Things, which connects things and sparks digital innovation. In addition, the era of ultra-delayed connectivity is coming, where various devices including sensors, which are a key means of promoting the production, distribution, and utilization of data, are connected. In the era of ultra-latency connectivity, large-capacity data traffic is required as communication frequency signals for multiple services are integrated due to the explosive increase in data traffic, convergence of broadcasting and communications, and increased use of cloud. For this purpose, in a high-speed optical communication network, an attenuator is needed to control the intensity of the optical signal power of the system equipment. Meanwhile, for efficient optical communication. An optical power meter that converts emitted output light into an electrical signal and measures optical power according to the wavelength is proposed in Korean Patent Publication No. 2011-0037428 and Domestic Registered Patent No. 10-1545453.

Meanwhile, in the case of a conventional wavelength-sensing power meter, photoelectric elements such as photodiodes are used depending on each wavelength, and ferrules (collimators), optical splitters, couplers, lenses, various filters, etc. It consists of However, conventional optical wavelength filters are inadequate for use in optical communication systems. Accordingly, there is a demand for a miniaturized optical power meter that can be effectively applied to the recently rapidly increasing optical communication system. In addition, it must satisfy the characteristics required for optical communication, such as being easily compatible with existing connectors, easy to install, inexpensive, and low installation cost.

The problem to be solved by the present invention is to provide a multi-channel optical power meter that is miniaturized to effectively respond to the recent explosion of optical communication systems and includes an optical wavelength filter to sufficiently satisfy the characteristics required for optical communication.

A multi-channel optical power meter including an optical wavelength filter to solve the problem of the present invention includes an optical splitter that separates the input optical signal according to the wavelength, and blocks and adjusts the optical power caused by the optical signal that has passed through the optical splitter. It includes a filter element unit that operates and multiple optical switches that open and close the optical signal that has passed through the filter element unit.

In the power meter of the present invention, it is disposed outside the filter element unit and includes a key locking unit including a fixing key, and the fixing key can be inserted into the key fixing part into which the filter element unit is inserted. The filter element portion includes first and second ferrule portions, and a protective tube is disposed between first and second steps of each of the first and second ferrule portions. The protective tube may be made of ceramic material. The cross-sections of the first and second ferrule bodies may be polished at an angle of 8 degrees and coated with an anti-reflective coating. The first ferrule portion may be press-fitted into a glass tube. The key lock unit includes a support tube, a flange, and the fixing key, and the fixing key may be formed on the flange. The fixing key is fixed to the key fixing part and maintains an angle of 8 degrees with respect to the optical signal.

According to the multi-channel optical power meter including the optical wavelength filter of the present invention, by applying the optical filter element portion, miniaturization is achieved, effectively responding to the recent explosion of optical communication systems, and sufficiently satisfying the characteristics required for optical communication.

1 is a block diagram for explaining an optical power meter according to the present invention.
Figure 2 is an exploded view showing the filter element according to the present invention.
Figures 3 and 4 are cross-sectional process views showing the process of manufacturing the filter element according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. The embodiments described below may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described in detail below. Examples of the present invention are provided to more completely explain the present invention to those skilled in the art. In the drawing, the representation is exaggerated for convenience of explanation. Meanwhile, terms indicating location, such as top, bottom, front, etc., are only related to what is shown in the drawing. In practice, the power meter can be used in any optional orientation, and in actual use the spatial orientation changes depending on the orientation and rotation of the power meter.

Embodiments of the present invention propose a multi-channel optical power meter that effectively responds to the recently exploding optical communication system by applying an optical filter element and miniaturization, and sufficiently satisfies the characteristics required for optical communication. To this end, the structure of the optical filter element will be studied in detail, and the optical power meter to which the attenuator is applied will be described in detail. The optical power meter according to an embodiment of the present invention converts output light emitted from multiple channels into electrical signals and measures optical power according to wavelength.

Figure 1 is a block diagram for explaining an optical power meter 100 according to an embodiment of the present invention. However, it is not a drawing in the strict sense, and there may be components not shown in the drawing for convenience of explanation.

According to FIG. 1, the optical power meter 100 includes an optical splitter 10, a filter element unit 20, a multiple optical switch 30, and a data processing unit 40 provided on a substrate SP. The optical signal is input to the optical splitter 10 and output to the multiple optical switches 30, and the emitted output light is appropriately processed by the data processing unit 40 to measure optical power and utilize it appropriately. The optical splitter 10 separates the optical signal whose wavelengths are multiplexed according to the wavelength, and the multiple optical switch 30 is a device that opens and closes the optical signal that has passed through the filter element unit 20, and all known methods can be applied. You can.

The fixing key 26c of the filter element unit 20 may be inserted into the key fixing part 11 of the substrate SP. In the drawing, the key fixing part 11 is expressed by specifying its position on the substrate SP. However, if the key fixing part 11 meets the scope of the present invention of fixing the filter element part 20 with a fixing key 26c, The shape and position of the key fixing part 11 may be modified in various ways. In this case, even if an external force acts on the optical power meter 100, the angle at which the filter element unit 20 is inserted (the angle with respect to the optical signal) is maintained at 8 degrees. The filter element unit 20 and the fixing key 26c will be described in detail later.

The data processing unit 40 includes a detection unit (A), a display 46, a power button 47, and an interface 48. The detection unit A includes an optical sensor 41 such as a photodiode, an amplification unit 42, a comparison unit 43, a signal processing unit 44, and a control unit 45. The optical sensor 41 detects the optical signal transmitted from the multiple optical switch 30 and converts it into an electrical signal, and the amplification unit 42 amplifies the optical power in the form of a current in which the photoelectric conversion has been performed. The comparison unit 43 detects the optical signal in the form of a current that has passed through the amplification unit 42 and compares it with the look-up optical signal. The signal processing unit 44 calculates the attenuation of optical power by the amplifying unit 42 and the comparing unit 43 and processes the calculated optical signal. For example, the optical signal can be converted into digital information using an A/D converter. For this purpose, the signal processing unit 44 and the comparison unit 43 are interconnected.

The display 46 displays the optical power detected through the detection unit A in numerical and graphic form, and the interface 48 allows connection to external devices. The control unit 45 is connected to the comparison unit 43, signal processing unit 44, display 46, and interface 48 and controls their operations. The data processing unit 40 presented above is merely an example, and measurements can be made in various forms within the scope of the present invention.

Figure 2 is an exploded view showing the filter element unit 20 according to an embodiment of the present invention. At this time, the optical power meter 100 will be referred to in FIG. 1 . Here, the filter element unit 20 is presented as an example, and may be modified in various ways within the scope of the present invention.

According to FIG. 2, the filter element portion 20 includes a first ferrule portion 21 and a second ferrule portion 23 spaced apart by a predetermined distance. The first ferrule portion 21 includes, for example, a first ferrule body 21a such as a stub ferrule and a first lens 21c such as a C type lens. The second ferrule portion 23 includes, for example, a second ferrule body 23a such as a stub ferrule and a second lens 23c such as a G type lens. At this time, since the first and second ferrule bodies 21a and 23a and the first and second lenses 21c and 23c are already well known, detailed description thereof will be omitted. The ends of the first and second ferrule bodies 21a and 23a are polished to 8 degrees and then anti-reflective coating is applied. The first ferrule body 21a includes a first step 21b, and the second ferrule portion 23 includes a second step 23b.

The first ferrule body 21a and the first lens 21c are finely aligned along the XYZ axes along the angular direction to reduce insertion loss, and the glass tube 22 is inserted and hardened with EMI3410 epoxy or the like. A thin film wavelength filter 24 is fixed with epoxy to one surface of the second ferrule body 23a and the second lens 23c, and finely aligned to reduce insertion loss in the XYZ axes according to the angular direction of light. EMI3410 epoxy is applied and cured. Within the scope of the present invention, the first and second lenses 21c and 23c may be appropriately selected and applied from spherical lenses, aspherical lenses, GRIN lenses, C-type lenses, G-type lenses, etc.

The thin film wavelength filter 24 functions to distribute a single optical power by radiating collimated optical signals from the first ferrule body 21a and the first lens 21c as parallel light. At this time, the first ferrule body 21a is polished to 8 degrees and then has an anti-reflective coating applied thereto. The thin film wavelength filter 24 is compatible with normal, coarse and dense wavelength division multiplexing (WDM, CWDM, DWDM). The thin film wavelength filter 24 can transmit only specific wavelengths of optical signals and reflect some of them. The degree to which the specific wavelength of light and insertion loss are transmitted may vary depending on the purpose and characteristics of the optical power meter 100. Although not shown in the drawings, a known special filter means may be separately disposed between the first and second ferrule portions 21 and 23.

The portion of the first ferrule body (21a) in contact with the first lens (21c) and the portion of the second ferrule body (23a) in contact with the second lens (23c) are polished at an 8-degree inclination to increase light transparency. An anti-reflective coating may be applied. The 8-degree inclined polishing reduces insertion loss and increases the light transmittance by allowing the optical signal to pass through the anti-reflective coating, thereby reducing light loss. A cylindrical protective tube 25 made of a ceramic material such as zirconia is disposed between the first and second steps 21b and 23b, and within the protective tube 25, the first ferrule body 21a has a smaller diameter. In the true part, the first lens 21c, the thin film wavelength filter 24, the second lens 23c, and the second ferrule body 23a, the part with a smaller diameter is built in. The first and second ferrule bodies 21a and 23a include optical fibers in a path through which optical signals are transmitted. The filter element portion 20 including the first and second ferrule portions 21 and 23 adopts an attenuator type.

Figures 3 and 4 are cross-sectional process views showing the process of manufacturing the filter element unit 20 according to an embodiment of the present invention. At this time, the optical power meter 100 will be referred to in FIG. 1 .

According to FIG. 3, the method of manufacturing the filter element portion 20 first prepares the first and second ferrule portions 21 and 23. Specifically, the first ferrule body (21a) on which the first step (21b) is formed is manufactured by polishing at an angle of 8 degrees and then applying an anti-reflective coating. That is, one end surface of the first ferrule body 21a is polished at an 8-degree angle to reduce insertion loss, and an anti-reflective coating is applied to the end surface. Thereafter, the first lens 21c is aligned with the first ferrule body 21a so that the insertion loss is less than 0.2 dB, and then bonded with an adhesive such as epoxy to complete the first ferrule portion 21. When the alignment of the first ferrule body (21a) and the first lens (21c) is completed, the first ferrule body (21a) and the first lens (21c) are bonded to the glass tube 22 with EMI-3410 epoxy, etc. and hardened. Do. At this time, it is preferable that one side of the glass tube 22 is in contact with the first step 21b.

The second ferrule body 23a with the second step 23b is manufactured by polishing at an angle of 8 degrees and then applying an anti-reflective coating. That is, one end face of the second ferrule body 23a may be polished at an 8-degree angle to reduce insertion loss, and the end face may be subjected to anti-reflection coating. Thereafter, the second lens 23c is aligned with the second ferrule body 23a and then bonded with an adhesive such as epoxy to complete the second ferrule portion 23. When the alignment of the second ferrule body 23a and the second lens 23c is completed, a thin film wavelength filter 24 is placed on one side of the second lens 23c, for example, along the angular direction so that the insertion loss is less than 0.25 dB. Finely align the XYZ axes and bond them with an adhesive such as epoxy. The thin film wavelength filter 24 radiates collimated optical signals from the first ferrule portion 21 as parallel light to transmit a specific desired wavelength and enables the manufacture of a device with a small insertion chamber.

According to Figure 4, the diameter of the portion of the first ferrule body 21a where the diameter is reduced, the first lens 21c, the thin film wavelength filter 24, the second lens 23c, and the second ferrule body 23a have a smaller diameter. The smaller part is embedded in the protective tube (25). That is, the protective tube 25 is made of a material such as ceramic, and is disposed between the first and second steps 21b and 23b. A key lock 26 consisting of a support tube 26a, a flange 26b, and a fixing key 26c is disposed outside the protection tube 25. The fixing key 26c provided on the flange 26b is inserted into the optical power meter 100 at a predetermined position. In this case, the filter element unit 20 is firmly fixed to the optical power meter 100, and the insertion angle of the filter element unit 20 is maintained at 8 degrees.

The optical power meter 100 according to an embodiment of the present invention can be applied to existing attenuator types such as SC/PC, SC/APC, FC/PC, FC/APC, LC/PC, LC/APC, etc. and can be easily connected to existing connectors. It is compatible and easy to install, and has low installation costs and low maintenance costs for transmitting multiple wavelengths of CWDM and DWDM in an optical communication multi-channel transmission network. Additionally, since the optical power meter 100 of the present invention is manufactured by a simple method, it is inexpensive.

Above, the present invention has been described in detail with preferred embodiments, but the present invention is not limited to the above embodiments, and various modifications can be made by those skilled in the art within the scope of the technical idea of the present invention. possible.

10; Optical splitter 11; Key fixation government
20; Filter element section
21, 23; 1st and 2nd ferrule
21a, 23a; first and second ferrule bodies
21b, 23b; 1st and 2nd steps
21c, 23c; 1st and 2nd lenses
22; Glass tube 24; Wavelength filter
25; Protective tube 26; Key lock
26a; Support tube 26b; Flange
26c; fixed key

Claims (8)

An optical splitter that separates the input optical signal according to its wavelength;
a filter element unit that blocks and adjusts optical power generated by the optical signal that has passed through the optical splitter; and
A multi-channel optical power meter including an optical wavelength filter including multiple optical switches that open and close the optical signal that has passed through the filter element unit. The optical wavelength filter according to claim 1, comprising a key locking unit disposed outside the filter element unit and including a fixing key, wherein the fixing key is inserted into a key fixing unit into which the filter element unit is inserted. Multi-channel optical power meter. The optical wavelength filter according to claim 1, wherein the filter element unit includes first and second ferrule units, and a protective tube is disposed between first and second steps of each of the first and second ferrule units. A multi-channel optical power meter including. The multi-channel optical power meter including an optical wavelength filter according to claim 3, wherein the protective tube is made of a ceramic material. The multi-channel optical power meter including an optical wavelength filter according to claim 3, wherein cross-sections of the first and second ferrule bodies are polished at an angle of 8 degrees and coated with an anti-reflection coating. The multi-channel optical power meter including an optical wavelength filter according to claim 3, wherein the first ferrule portion is press-fitted into a glass tube. The multi-channel optical power meter including an optical wavelength filter according to claim 1, wherein the key lock unit includes a support tube, a flange, and the fixing key, and the fixing key is formed on the flange. The multi-channel optical power meter including an optical wavelength filter according to claim 1, wherein the fixing key is fixed to the key fixing part to maintain an angle of 8 degrees with respect to the optical signal.

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