WO2023093275A1 - Light source assembly and optical module - Google Patents

Abstract

Some embodiments of the present disclosure provide a light source assembly and an optical module. The light source assembly and the optical module comprise a laser chip and a plurality of lasers. The plurality of lasers are configured on a surface of the laser chip. Each laser comprises a gain area and a grating area. The gain area and the grating area are each provided with an optical waveguide. The plurality of lasers comprise a first set of lasers and a second set of lasers. The grating area of each laser in the first set of lasers is configured to receive an external current to output a first light beam having a corresponding wavelength. An angle of inclination is present between the optical waveguide of the grating area and the optical waveguide of the gain area of each laser in the second set of lasers, so as to output a second light beam having a corresponding wavelength. The wavelength of the second light beam is different from the wavelength of the first light beam.

Description

A light source component and an optical module

This application claims the priority of the Chinese patent application with application number 202122905995.4, filed on November 24, 2021, the entire contents of which are incorporated in this application by reference.

technical field

The present disclosure relates to the technical field of optical communication, in particular to a light source component and an optical module.

Background technique

Realizing the photoelectric conversion function by silicon photonics chips has become a mainstream solution currently adopted by high-speed optical modules. Since the silicon material used in the silicon photonics chip is not an ideal light-emitting material for laser chips, the light-emitting unit cannot be integrated in the silicon photonics chip manufacturing process, so the silicon photonics chip needs to be provided by an external light source. In the design of contemporary high-speed silicon photonics chips, improving the integration of light sources is the main trend.

Contents of the invention

In one aspect, some embodiments of the present disclosure provide a light source assembly. The light source component includes a laser chip and multiple lasers. The multiple lasers are arranged on the surface of the laser chip, and each laser includes a gain region and a grating region, and both the gain region and the grating region have an optical waveguide. The plurality of lasers includes a first set of lasers and a second set of lasers. The grating region of each laser in the first group of lasers is configured to receive an external current to output a first beam of corresponding wavelength, the optical waveguide of the grating region of each laser in the second group of lasers and the optical waveguide of the gain region There is an inclination angle between them, so as to output the second light beam corresponding to the wavelength. The first light beam and the second light beam have different wavelengths.

On the other hand, some embodiments of the present disclosure provide an optical module. The optical module includes a circuit board, the above-mentioned light source assembly and a silicon photonics chip. The light source assembly is connected to the circuit board. The silicon photonic chip is electrically connected to the circuit board and optically connected to the light source component, and is configured to receive the light beam emitted by the light source component.

Description of drawings

In order to illustrate the technical solutions in the present disclosure more clearly, the following will briefly introduce the accompanying drawings required in some embodiments of the present disclosure. Obviously, the accompanying drawings in the following description are only appendices to some embodiments of the present disclosure. Figures, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings. In addition, the drawings in the following description can be regarded as schematic diagrams, and are not limitations on the actual size of the product involved in the embodiments of the present disclosure, the actual process of the method, the actual timing of signals, and the like.

Fig. 1 is a connection diagram of an optical communication system according to some embodiments;

Fig. 2 is a structural diagram of an optical network terminal according to some embodiments;

Fig. 3 is a structural diagram of an optical module according to some embodiments;

Figure 4 is an exploded view of an optical module according to some embodiments;

5 is a schematic diagram of the structure and materials along the growth direction outside the gain region (left) and the grating region (right) of a laser according to some embodiments;

6 is a cross-sectional view of the optical waveguide in the gain region and the optical waveguide in the grating region of the laser according to some embodiments;

7 is a schematic diagram of the distribution of lasers arranged on a laser chip according to some embodiments;

FIG. 8 is a schematic diagram of a specific design of a gain region and a grating region of a laser according to some embodiments;

9 is a schematic diagram showing the relationship between the inclination angle of the optical waveguide extension direction of the grating region and the wavelength variation relative to the optical waveguide extension direction of the gain region according to some embodiments;

10 is a schematic diagram of wavelengths for a 10-channel laser of a light source assembly according to some embodiments.

Detailed ways

The technical solutions in some embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present disclosure, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments provided in the present disclosure belong to the protection scope of the present disclosure.

Throughout the specification and claims, unless the context requires otherwise, the term "comprise" and other forms such as the third person singular "comprises" and the present participle "comprising" are used Interpreted as the meaning of openness and inclusion, that is, "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "exemplary embodiments", "example", "specific examples" example)" or "some examples (some examples)" etc. are intended to indicate that specific features, structures, materials or characteristics related to the embodiment or examples are included in at least one embodiment or example of the present disclosure. Schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be included in any suitable manner in any one or more embodiments or examples.

Hereinafter, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features. Thus, a feature defined as "first" and "second" may explicitly or implicitly include one or more of these features. In the description of the embodiments of the present disclosure, unless otherwise specified, "plurality" means two or more.

In describing some embodiments, the expressions "coupled" and "connected" and their derivatives are used. The term "connection" should be understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral body; it can be a direct connection or an indirect connection through an intermediary. As another example, the term "coupled" may be used in describing some embodiments to indicate that two or more elements are in direct physical or electrical contact. However, the terms "coupled" or "communicatively coupled" may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other. The embodiments disclosed herein are not necessarily limited by the context herein.

"At least one of A, B and C" has the same meaning as "at least one of A, B or C" and both include the following combinations of A, B and C: A only, B only, C only, A and B A combination of A and C, a combination of B and C, and a combination of A, B and C.

"A and/or B" includes the following three combinations: A only, B only, and a combination of A and B.

The use of "suitable for" or "configured to" herein means open and inclusive language that does not exclude devices that are suitable for or configured to perform additional tasks or steps.

As used herein, "about", "approximately" or "approximately" includes the stated value as well as the average within the acceptable deviation range of the specified value, wherein the acceptable deviation range is as determined by one of ordinary skill in the art. Determined taking into account the measurement in question and the errors associated with the measurement of a particular quantity (ie, limitations of the measurement system).

Exemplary embodiments are described herein with reference to cross-sectional and/or plan views that are idealized exemplary drawings. In the drawings, the thickness of layers and regions are exaggerated for clarity. Accordingly, variations in shape from the drawings as a result, for example, of manufacturing techniques and/or tolerances are contemplated. Thus, example embodiments should not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an etched region illustrated as a rectangle will, typically, have curved features. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments.

In an optical communication system, optical signals are used to carry information to be transmitted, and the optical signals carrying information are transmitted to information processing equipment such as computers through optical fibers or optical waveguides to complete information transmission. Due to the passive transmission characteristics of light when transmitted through optical fibers or optical waveguides, low-cost, low-loss information transmission can be achieved. In addition, the signals transmitted by information transmission equipment such as optical fibers or optical waveguides are optical signals, while the signals that can be recognized and processed by information processing equipment such as computers are electrical signals. To establish an information connection between them, it is necessary to realize the mutual conversion of electrical signals and optical signals.

The optical module realizes the mutual conversion function of the above-mentioned optical signal and electrical signal in the technical field of optical fiber communication. The optical module includes an optical port and an electrical port. The optical module realizes optical communication with information transmission equipment such as optical fiber or optical waveguide through the optical port, and realizes the electrical connection with the optical network terminal (such as an optical modem) through the electrical port. It is mainly used for power supply, I2C signal transmission, data information transmission and grounding, etc.; the optical network terminal transmits electrical signals to information processing equipment such as computers through network cables or wireless fidelity technology (Wi-Fi).

Fig. 1 is a connection diagram of an optical communication system according to some embodiments. As shown in FIG. 1 , the optical communication system includes a remote server 1000 , a local information processing device 2000 , an optical network terminal 100 , an optical module 200 , an optical fiber 101 and a network cable 103 .

One end of the optical fiber 101 is connected to the remote server 1000 , and the other end is connected to the optical network terminal 100 through the optical module 200 . Optical fiber itself can support long-distance signal transmission, such as signal transmission of several kilometers (6 kilometers to 8 kilometers). On this basis, if repeaters are used, theoretically unlimited distance transmission can be achieved. Therefore, in a common optical communication system, the distance between the remote server 1000 and the optical network terminal 100 can usually reach thousands of kilometers, tens of kilometers or hundreds of kilometers.

One end of the network cable 103 is connected to the local information processing device 2000 , and the other end is connected to the optical network terminal 100 . The local information processing device 2000 may be any one or more of the following devices: routers, switches, computers, mobile phones, tablet computers, televisions, and so on.

The physical distance between the remote server 1000 and the optical network terminal 100 is greater than the physical distance between the local information processing device 2000 and the optical network terminal 100 . The connection between the local information processing device 2000 and the remote server 1000 is completed by the optical fiber 101 and the network cable 103 ; and the connection between the optical fiber 101 and the network cable 103 is completed by the optical module 200 and the optical network terminal 100 .

The optical module 200 includes an optical port and an electrical port, and the optical port is configured to be connected to the optical fiber 101, so that the optical module 200 and the optical fiber 101 establish a bidirectional optical signal connection; the electrical port is configured to be connected to the optical network terminal 100, so that The optical module 200 establishes a bidirectional electrical signal connection with the optical network terminal 100 . The optical module 200 implements mutual conversion between optical signals and electrical signals, so that an information connection is established between the optical fiber 101 and the optical network terminal 100 . For example, the optical signal from the optical fiber 101 is converted into an electrical signal by the optical module 200 and then input to the optical network terminal 100 , and the electrical signal from the optical network terminal 100 is converted into an optical signal by the optical module 200 and input to the optical fiber 101 . Since the optical module 200 is a tool for realizing mutual conversion of photoelectric signals and does not have the function of processing data, the information does not change during the above photoelectric conversion process.

The optical network terminal 100 includes a substantially rectangular parallelepiped housing (housing), and an optical module interface 102 and a network cable interface 104 disposed on the housing. The optical module interface 102 is configured to access the optical module 200, so that the optical network terminal 100 and the optical module 200 establish a bidirectional electrical signal connection; the network cable interface 104 is configured to access the network cable 103, so that the optical network terminal 100 and the network cable 103 A two-way electrical signal connection is established. A connection is established between the optical module 200 and the network cable 103 through the optical network terminal 100 . For example, the optical network terminal 100 transmits the electrical signal from the optical module 200 to the network cable 103, and transmits the electrical signal from the network cable 103 to the optical module 200, so the optical network terminal 100, as the host computer of the optical module 200, can monitor the optical module 200 jobs. In addition to the optical network terminal 100, the host computer of the optical module 200 may also include an optical line terminal (Optical Line Terminal, OLT) and the like.

The remote server 1000 establishes a two-way signal transmission channel with the local information processing device 2000 through the optical fiber 101 , the optical module 200 , the optical network terminal 100 and the network cable 103 .

FIG. 2 is a structural diagram of an optical network terminal according to some embodiments. In order to clearly show the connection relationship between the optical module 200 and the optical network terminal 100, FIG. 2 only shows the optical network terminal 100 related to the optical module 200. structure. As shown in Figure 2, the optical network terminal 100 also includes a circuit board 105 disposed in the casing, a cage 106 disposed on the surface of the circuit board 105, a radiator disposed on the cage 106, and an electrical connector disposed inside the cage 106 . The electrical connection is configured to be connected to the electrical port of the optical module 200 ; the heat sink 107 has a raised structure such as a fin that increases the heat dissipation area.

The optical module 200 is inserted into the cage 106 of the optical network terminal 100 , and the optical module 200 is fixed by the cage 106 . The heat generated by the optical module 200 is conducted to the cage 106 and then diffused through the radiator 107 . After the optical module 200 is inserted into the cage 106 , the electrical port of the optical module 200 is connected to the electrical connector inside the cage 106 , so that the optical module 200 establishes a bidirectional electrical signal connection with the optical network terminal 100 . In addition, the optical port of the optical module 200 is connected to the optical fiber 101 , so that the optical module 200 establishes a bidirectional optical signal connection with the optical fiber 101 .

Fig. 3 is a structural diagram of an optical module according to some embodiments, and Fig. 4 is an exploded structural diagram of an optical module according to some embodiments. As shown in FIG. 3 and FIG. 4 , the optical module 200 includes a housing, a circuit board 300 disposed in the housing, a silicon photonics chip 400 and a light source assembly 500 .

The casing includes an upper casing 201 and a lower casing 202. The upper casing 201 is covered on the lower casing 202 to form the above-mentioned casing with two openings; the outer contour of the casing generally presents a square shape.

In some embodiments of the present disclosure, the lower shell 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and perpendicular to the bottom plate 2021; the upper shell 201 includes a cover plate 2011, and the cover plate 2011 covers Two lower side panels 2022 of the housing 202 to form the above housing.

In some embodiments, the lower case 202 includes a bottom plate 2021 and two lower side plates 2022 located on both sides of the bottom plate 2021 and perpendicular to the bottom plate 2021; The two upper side plates 2012 perpendicular to the cover plate 2011 are combined with the two lower side plates 2022 so as to cover the upper case 201 on the lower case 202 .

The direction of the line connecting the two openings 204 and 205 may be consistent with the length direction of the optical module 200 , or may not be consistent with the length direction of the optical module 200 . For example, the opening 204 is located at the end of the optical module 200 (the left end in FIG. 3 ), and the opening 205 is also located at the end of the optical module 200 (the right end in FIG. 3 ). Alternatively, the opening 204 is located at the end of the optical module 200 , while the opening 205 is located at the side of the optical module 200 . The opening 204 is an electrical port, and the golden finger 301 of the circuit board 300 extends from the electrical port 204, and is inserted into the upper computer (for example, the optical network terminal 100); the opening 205 is an optical port, which is configured to be connected to the external optical fiber 101, so that The external optical fiber 101 is connected to the silicon photonics chip 400 inside the optical module 200 .

The combination of the upper housing 201 and the lower housing 202 is used to facilitate the installation of components such as the circuit board 300, the silicon photonics chip 400 and the light source assembly 500 into the housing, and the upper housing 201 and the lower housing 202 control these devices. Form package protection. In addition, when assembling components such as the circuit board 300 , the silicon photonics chip 400 , and the light source assembly 500 , it facilitates the deployment of positioning components, heat dissipation components, and electromagnetic shielding components of these components, and facilitates automatic production.

In some embodiments, the upper shell 201 and the lower shell 202 are generally made of metal materials, which is beneficial to realize electromagnetic shielding and heat dissipation.

In some embodiments, the optical module 200 also includes an unlocking component 203 located outside the housing, configured to realize the fixed connection between the optical module 200 and the host computer, or release the fixed connection between the optical module 200 and the host computer .

Exemplarily, the unlocking part 203 is located on the outer side of the two lower side plates 2022 of the lower housing 202, and has a locking part matching with the upper computer cage (for example, the cage 106 of the optical network terminal 100). When the optical module 200 is inserted into the cage of the host computer, the optical module 200 is fixed in the cage of the host computer by the engaging part of the unlocking part 203; when the unlocking part 203 is pulled, the engaging part of the unlocking part 203 moves accordingly, thereby changing The connection relationship between the engaging part and the host computer is to release the engagement relationship between the optical module 200 and the host computer, so that the optical module 200 can be pulled out from the cage of the host computer.

The circuit board 300 includes circuit traces, electronic components and chips, through which the electronic components and chips are connected together according to the circuit design, so as to realize functions such as power supply, electrical signal transmission and grounding. The electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET). The chip can include, for example, a Microcontroller Unit (MCU), a Limiting Amplifier (LA), a Clock and Data Recovery chip (CDR), a power management chip, and a Digital Signal Processing (DSP) chip. ) chip, transimpedance amplifier (Trans-Impedance Amplifier).

The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the bearing function, such as the rigid circuit board can stably carry the above-mentioned electronic components and chips; the rigid circuit board can also be inserted into the upper computer cage 106 in the electrical connector.

The circuit board 300 also includes a gold finger 301 formed on the surface of its end, and the gold finger 301 is composed of a plurality of independent pins. The circuit board 300 is inserted into the cage 106 , and is conductively connected with the electrical connector in the cage 106 by the gold finger 301 . Gold fingers 301 can be set on only one side of the circuit board 300 (such as the upper surface shown in FIG. 4 ), or can be set on the upper and lower sides of the circuit board 300, so as to meet the occasions where the number of pins is large. The golden finger 301 is configured to establish an electrical connection with a host computer to realize power supply, grounding, I2C signal transmission, data signal transmission, and the like.

Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards as a supplement to rigid circuit boards.

The optical module of the silicon photonics structure also includes a silicon photonic chip 400 and a light source assembly 500 . The light source assembly 500 can be a laser box, and a laser chip is packaged inside the laser box, and the laser chip emits light. The light source assembly 500 is used to provide a laser beam to the silicon photonics chip 400 .

The silicon photonics chip 400 is optically connected to the light source assembly 500 . The light emitted by the light source assembly 500 enters the silicon photonics chip 400 , and the silicon photonics chip 400 receives the light from the light source assembly 500 . In some embodiments, the light source assembly 500 provides light with a single wavelength, stable power, and no information to the silicon photonic chip 400, and the silicon photonic chip 400 modulates the light to load the data to be transmitted into the light to form an optical signal . In addition, the silicon photonic chip 400 also receives an optical signal from outside the optical module, and converts the optical signal into a current signal to extract data from the optical signal. That is to say, both the modulation of the light emitted by the optical module 200 and the demodulation of the optical signal received by the optical module 200 are completed by the silicon optical chip 400 .

In some embodiments, the circuit board 300 provides the silicon photonic chip 400 with an electrical signal from the host computer, and the silicon photonic chip 400 receives the light that does not carry information output by the light source assembly 500, and modulates the received light based on the above electrical signal An optical signal is formed, and the optical signal is sent to the outside of the optical module 200, so that the electrical signal is converted into an optical signal. The optical signal from the outside of the optical module 200 is converted into a current signal by the silicon optical chip 400, and the current signal is converted into a differential voltage signal by the transimpedance amplifier, and the differential voltage signal is output to the In the upper computer, the optical signal is converted into an electrical signal.

In order to realize the above optical signal modulation and demodulation process, it is necessary to assemble the circuit board 300, the silicon photonics chip 400 and the light source assembly 500 according to predetermined positions, so as to form a predetermined light propagation path.

Since the optical path is very sensitive to the positional relationship between the silicon photonics chip 400 and the light source assembly 500 , materials with different expansion coefficients will cause different degrees of deformation, which is not conducive to the realization of the preset optical path. In some embodiments of the present disclosure, the silicon photonics chip 400 and the light source assembly 500 are disposed on the same substrate, and the substrate is a plate structure made of the same material. The deformation of the substrate of the same material has the same impact on the silicon photonics chip 400 and the light source assembly 500 , and the change of the relative position between the silicon photonics chip 400 and the light source assembly 500 can be avoided. This embodiment does not limit the material of the substrate. Exemplarily, the expansion coefficient of the substrate material is close to the thermal expansion coefficient of the silicon photonic chip 400 and/or the light source assembly 500. For example, the main material of the silicon photonic chip 400 is silicon. The light source assembly 500 can be made of Kovar alloy, and the substrate can be made of silicon or glass. Kovar alloy, also known as iron-nickel-cobalt alloy, or iron-nickel-cobalt glass sealing alloy, generally contains 29% nickel, 18% cobalt, and the rest is iron. The thermal expansion coefficient of Kovar alloy is reduced by the addition of cobalt, which is similar to that of glass, and is suitable for matching and sealing with glass.

It can be known from the above that the silicon photonics chip 400 and the light source assembly 500 are usually disposed on the same side of the circuit board 300 . At this time, there are various positional relationships between the substrate and the circuit board 300 .

In some embodiments, as shown in FIG. 4 , the circuit board 300 has a through hole through the upper and lower surfaces, the substrate is disposed in the through hole, and the silicon photonics chip 400 and/or the light source assembly 500 are disposed on the substrate. In this way, not only can the relative position change between the silicon photonics chip 400 and the light source assembly 500 be avoided, but also the electrical connection between the silicon photonics chip 400 and/or the light source assembly 500 and the circuit board 300 is facilitated. In addition, the silicon photonics chip 400 and/or the light source assembly 500 can dissipate heat to the substrate, so that the substrate can simultaneously have the effect of supporting and dissipating heat.

In other embodiments, the circuit board 300 is not provided with through holes, and the substrate is provided on the circuit board. Specifically, the substrate may be provided on the surface of the circuit board 300 or embedded in the circuit board 300. The silicon photonic chip 400 and the light source assembly 500 are provided on the substrate surface.

It should be noted that the light output surface of the light source assembly 500 is the surface of the light source assembly 500 near the silicon photonic chip 400 , and the light incident surface of the silicon photonic chip 400 is the surface of the silicon photonic chip 400 near the light source assembly 500 .

The optical module 200 also includes a first internal optical fiber ribbon 600, a second internal optical fiber ribbon 700, and an optical fiber interface 800. Each of the first internal optical fiber ribbon 600 and the second internal optical fiber ribbon 700 is formed by a plurality of internal optical fibers arranged in parallel and cured by ultraviolet light. thin flat strips. In some embodiments of the present disclosure, the first inner fiber optic ribbon 600 is a launch fiber optic ribbon and the second inner fiber optic ribbon 700 is a receive fiber optic ribbon. One end of the first internal optical fiber ribbon 600 is connected to the silicon photonics chip 400 , and the other end is connected to the optical fiber interface 800 . One end of the second internal optical fiber ribbon 700 is connected to the silicon photonics chip 400 , and the other end is connected to the optical fiber interface 800 . The optical fiber interface 800 is connected with the external optical fiber 101 . It can be seen that the optical connection between the silicon photonics chip 400 and the optical fiber interface 800 is realized through the first internal optical fiber ribbon 600 and the second internal optical fiber ribbon 700, and the optical fiber interface 800 is optically connected to the external optical fiber 101 of the optical module.

The light source assembly 500 transmits the light that does not carry information to the silicon photonics chip 400, and the silicon photonics chip 400 modulates the light that does not carry information, that is, loads data into the light that does not carry information, and then modulates the light that does not carry information into The light (optical signal) carrying information, the light (optical signal) carrying information is transmitted to the optical fiber interface 800 through the first internal optical fiber ribbon 600, and then transmitted to the external optical fiber 101 through the optical fiber interface 800, so that the light carrying information ( Optical signal) is transmitted to the external optical fiber 101 to convert the electrical signal into an optical signal.

The optical signal from the external optical fiber 101 is transmitted to the silicon optical chip 400 through the optical fiber interface 800 and the second internal optical fiber ribbon 700. The silicon optical chip 400 demodulates the optical signal into an electrical signal, and outputs it to the host computer through the circuit board 300. Realize the conversion of optical signals into electrical signals.

In order to realize the integration of multi-channel light sources, multiple laser chips are usually mechanically welded on the same substrate, and the electrodes of the laser chips are connected to the electrodes of the substrate through gold wires to realize the integration of light sources at the substrate level. Since the laser chip is fixed on the substrate by mechanical operation, the precision of industrial operation is low, and the distance between adjacent laser chips is maintained at the order of mm, so the integration degree of the light source in this way is low.

The light source assembly 500 in some embodiments of the present disclosure includes a laser chip and multiple lasers, and the multiple lasers are arranged on the laser chip. Some embodiments of the present disclosure take a laser chip with a size of 1*4mm as an example. In some embodiments of the present disclosure, multiple lasers are arranged on a single laser chip to realize chip-level light source integration, thereby improving the light source integration degree. In addition, multiple lasers on the single laser chip output light beams of different wavelengths to realize wavelength division multiplexing, improve bandwidth usage efficiency, and thereby improve information transmission efficiency and speed.

In some embodiments of the present disclosure, a laser array is provided on the surface of the laser chip, and the laser array includes at least two lasers, each laser includes a gain region, a grating region, and a Fabry-Perot resonator connected to the grating region, and the gain region is Configured to emit light when excited by the gain energizing signal, the grating region is configured to modulate the wavelength of the light when excited by the Bragg reflective grating energizing signal. The Fabry Perot resonant cavity tailed by the grating region is configured to output the optical signal transmitted by the grating region.

5 is a schematic diagram of the structure and materials along the growth direction outside the gain region (left) and the grating region (right) of the laser according to some embodiments; FIG. 6 is the optical waveguide structure in the gain region and the grating region of the laser according to some embodiments Sectional view. As shown in FIG. 5 and FIG. 6 , in some embodiments of the present disclosure, the grating region includes a grating layer, a waveguide layer and electrodes stacked in sequence. It can be understood that the grating layer can also be called a grating, and the waveguide layer can also be called an optical waveguide.

The grating layer in the grating area may be a distributed Bragg reflection grating, and an InGaAsP material with a photoluminescence peak of 1150 nm and a thickness of 450 A ^O . The waveguide layer in the grating area is made of InGaAsP material with a photoluminescence peak of 1170nm and a thickness of 3100A ^O , and the width of the waveguide layer in the grating area is controlled at about 1.5 μm to achieve a single-mode waveguide.

The gain region includes waveguide layers and electrodes stacked in sequence. It can be understood that the waveguide layer can also be called an optical waveguide.

The electrode of the gain area is electrically connected with an external current source, and the gain area emits light under the excitation of the gain power signal, and the light is transmitted to the grating area through the optical waveguide of the gain area, and the optical waveguide of the grating area is connected to the grating area. The Fabry Perot resonator is transmitted to the light entrance of the silicon photonics chip.

The electrodes of one of the laser grating regions in the laser array are electrically connected to another external current source, and the output of first light beams with different wavelengths is achieved by changing the current magnitude of the Bragg reflection grating energizing signal injected into the grating region. The extension direction of the optical waveguide of the grating region of the other laser in the laser array is inclined relative to the extension direction of the optical waveguide of the gain region to form an inclination angle, and outputting second beams of different wavelengths is achieved by changing the inclination angle. The wavelength of the second light beam is greater than the wavelength of the first light beam.

At least two lasers output at least two beams with different wavelengths by changing the magnitude of the current injected into the grating region, and changing the inclination angle between the extending direction of the optical waveguide in the gain region and the extending direction of the optical waveguide in the grating region, so that wave Multiplexing, improve the efficiency of bandwidth usage, and then improve the efficiency and speed of information transmission. The present disclosure can realize the integration of at least two lasers at the laser chip level, and realize the precise modulation of wavelength through carrier (current carrier) injection change and inclined waveguide design.

Figure 7 is a schematic diagram of the distribution of lasers arranged on the laser chip according to some embodiments; Figure 7 shows that the surface of the laser chip is respectively provided with a first signal laser, a first photodetector, a first laser, a A laser, a third laser, a fourth laser, a fifth laser, a sixth laser, a seventh laser, an eighth laser, a ninth laser, a tenth laser, a second photodetector and a second signal laser. The first signal laser, the first photodetector, the second photodetector and the second signal laser are used for active alignment of 10 lasers.

In Fig. 7, the optical devices labeled 11, 21, 20, and 10 are respectively the first signal laser, the first photodetector, the second photodetector and the second signal laser; the optical devices labeled 0-9 are respectively 10 The lasers of channels, the lasers of channel 0, channel 1, channel 2, channel 3, channel 4, channel 5, channel 6, channel 7, channel 8 and channel 9 in Fig. 7 Corresponding to the first laser, the second laser, the third laser, the fourth laser, the fifth laser and the sixth laser, the seventh laser, the eighth laser, the ninth laser and the tenth laser.

In this way, 10 lasers, 2 signal lasers and 2 photodetectors are arranged on the surface of the laser chip, and the anodes of the 10 lasers are all connected to the surface of the laser chip through their surfaces, so as to be electrically connected to an external current source. Each laser is connected to two electrical signals, which are the gain power-on signal and the Bragg reflection grating power-on signal. The grating area of the laser.

Among the 10 lasers marked 0-9 in Figure 7, each laser is 1 channel, and there are 10 channels in total. According to the standard of wavelength division multiplexing, the interval between adjacent channels should be 200 GHz.

The distance between adjacent lasers in the 10-channel laser is 250 μm. There are two factors that affect the distance between lasers. One factor is the requirements of the receiving end of the silicon photonic chip that matches the laser; the other factor is the size of the laser spot. . The distance of 250 μm between adjacent lasers is an order of magnitude that cannot be achieved by the traditional solution of multiple laser chips arranged on a substrate. In some embodiments of the present disclosure, taking the 1280nm wavelength band as an example, multiple lasers are arranged on a single laser chip to realize simultaneous emission of light beams with different wavelengths.

In some embodiments of the present disclosure, the first laser, the second laser, the third laser, the fourth laser, the fifth laser and the sixth laser are divided into the first group of lasers, and the seventh laser, the eighth laser, the ninth laser The laser and the tenth laser are divided into the second group of lasers; the first group of lasers optimizes the material of the optical waveguide in the grating area, and at the same time cooperates with the change of injected carriers into the optical waveguide in the grating area, to achieve a short wavelength relative to the target wavelength band (1280nm). In the direction of wavelength (1275nm-1280nm), the wavelength modulation range of the Bragg grating tailed with the Fabry-Perot resonator itself is increased; the second group of lasers adopts an oblique waveguide design, and the direction of the long wavelength (1280nm-1285nm) relative to the target band (1280nm) Increase the wavelength modulation range; this eventually enables each laser on the laser chip to achieve a wavelength modulation range of 10nm.

In some embodiments of the related technology, a temperature adjustment device is provided inside the grating area of the laser, such as a heating device, and the wavelength can be tuned by changing the temperature of the grating area. This tuning method is called thermal tuning; the grating area of the laser There are electrodes inside, and the wavelength is tuned by inputting currents of different sizes to the grating area through the electrodes. This tuning method is called electrical tuning; There is an inclination angle between the extension direction of the optical waveguide in the gain region, and the wavelength can be tuned by changing the inclination angle. This tuning method is called mechanical tuning. These three tuning modes can be combined in different ways in different embodiments to realize the adjustment of the wavelength.

In some embodiments of the present disclosure, the gain region of the laser generates photons due to the excitation of the injection current and is amplified. The distributed Bragg reflection grating in the grating region selects the frequency of the amplified light wave, and the specific wavelength is in the tailed Fabry The Perot resonant cavity is reflected and oscillated back and forth, so as to realize the output of laser light.

Illustratively, each laser in the first group of lasers outputs first light beams with different wavelengths by changing the current magnitude of the Bragg reflection grating energizing signal injected into each grating region; the optical waveguide extension direction of each grating region of each laser in the second group of lasers The extension direction of the optical waveguide is inclined relative to the gain region, and second light beams with different wavelengths are output by changing the size of the inclination angle.

The gratings in the grating areas of the first laser, the second laser, the third laser, the fourth laser, the fifth laser and the sixth laser in the first group of lasers are all distributed Bragg reflection gratings, and the entire laser chip is only subjected to a holographic exposure A grating is formed so that the period of the grating is fixed.

In related technologies, since the laser peak position of the distributed grating is affected by the phase of the end face, precise control of the wavelength cannot be achieved; although phase gratings, loss gratings, and gain gratings can solve the phase control problem, the process is complicated and the efficiency is not high. Power efficiency has an impact. In contrast, a distributed Bragg reflection grating tailed with a Fabry-Perot resonator is a simple and practical solution. In some embodiments of the present disclosure, a distributed Bragg reflection grating in the grating area is used to tail the Fabry-Perot resonant cavity, so as to avoid the random distribution of laser peaks affected by the phase in the filter channel band, and realize precise control of the wavelength.

Compared with mechanical tuning and thermal tuning for wavelength adjustment, electrical tuning for wavelength adjustment has a larger wavelength adjustment range and faster wavelength switching speed, which can better meet the needs of optical fiber communication for lasers. In some embodiments of the present disclosure, electrical tuning is achieved by injecting carriers into the grating region to change the refractive index of the material in the grating region. As an example, by changing the current magnitude of the Bragg reflection grating energization signal applied to the grating area, the refractive index of the optical waveguide in the grating area can be continuously changed, thereby realizing the continuous change of the grating passband, and selecting the Fabryper corresponding to the target wavelength. Luo mode.

When current is injected into the grating region, the free carrier plasma effect causes the refractive index to change, and the projected spectrum of the grating will shift to the short wavelength direction at this time.

Therefore, in some embodiments of the present disclosure, a Bragg reflection grating power-on signal is applied to the grating area to reduce the internal refractive index of the laser, thereby shortening the effective wavelength and moving to a relatively short wavelength (1275nm-1280nm) direction relative to 1280nm to achieve a relative target wavelength. The wavelength modulation range of 5nm in the short wavelength direction.

In this way, by optimizing the material of the optical waveguide in the grating area, the first group of lasers increases the distributed Bragg frequency in the direction of short wavelength (1275nm-1280nm) by cooperating with the optical waveguide in the grating area and the change of the current magnitude of the distributed Bragg reflection grating power signal. The reflective grating is connected to the wavelength modulation range of the Fabry-Perot cavity itself; the wavelength modulation can cover the wavelength variation requirements of 6-way lasers from 0 to 5. The carrier injection into the optical waveguide in the grating region leads to a change in the refractive index of the waveguide, and ultimately a wavelength change.

Fig. 8 is a specific design schematic diagram of the gain region (left) and the grating region (right) of the laser chip according to some embodiments; The extension direction of the waveguide is inclined, thereby increasing the grating period experienced by the optical waveguide in the grating area, making the effective wavelength larger, and realizing the wavelength modulation of 5nm in the long wavelength direction relative to the target wavelength in the direction of the long wavelength (1280nm-1285nm) relative to 1280nm scope.

Exemplarily, the gratings of the seventh laser, the eighth laser, the ninth laser and the tenth laser in the second group of lasers are also distributed Bragg reflection gratings, and the sixth laser, the seventh laser, the ninth laser and the tenth laser The extension direction of the optical waveguide in the grating area is inclined relative to the extension direction of the optical waveguide in the gain area, that is, there is an inclination angle between the extension direction of the optical waveguide in the grating area and the extension direction of the optical waveguide in the gain area, by changing the inclination angle The size outputs a second light beam of a different wavelength.

The magnitude of the output wavelength of the laser is proportional to the grating period experienced by the optical waveguide in the grating area. Some embodiments of the present disclosure set the optical waveguide in the grating area as an oblique waveguide relative to the extending direction of the optical waveguide in the gain area to increase the grating area. The grating period experienced by the optical waveguide makes the wavelength of the laser output light larger than that of 1280nm, and achieves a wavelength modulation range of 5nm in the long wavelength direction relative to the target wavelength in the direction of the long wavelength (1280nm-1285nm) relative to 1280nm.

In some embodiments of the present disclosure, the inclination angles between the extending direction of the optical waveguide in the grating region of the seventh laser, the eighth laser, the ninth laser, and the tenth laser and the extending direction of the optical waveguide in the gain region are 2.57 degrees and 3.63 degrees respectively. degrees, 4.44 degrees and 5.15 degrees, the equivalent grating period changes are 1947.09A, 1949.05A, 1951.01A, 1953.03A, and the modulation range of wavelength from 1280nm to 1285nm can be realized.

In some embodiments of the present disclosure, a variety of wavelength modulation techniques are used. The first group of 6 laser channels optimizes the material of the optical waveguide in the grating area, and at the same time cooperates with the change of injected carriers into the optical waveguide in the grating area. The short-wavelength direction of the target band is modulated; the second group of 4 laser channels is modulated in the long-wavelength direction relative to the target band by adopting an oblique waveguide structure.

Fig. 9 is a schematic diagram showing the relationship between the inclination angle of the optical waveguide extension direction of the grating region relative to the optical waveguide extension direction of the gain region and the wavelength change of the laser according to some embodiments, and the labels in Fig. 9 are 1, 2, 3, 4 and 5 The change lines respectively correspond to inclination angles with angles of 0 degree, 2.57 degrees, 3.63 degrees, 4.44 degrees and 5.15 degrees. As shown in Figure 9, the inclination angles between the extending direction of the optical waveguide of the grating region of the seventh laser, the eighth laser, the ninth laser and the tenth laser and the extending direction of the optical waveguide of the gain region are 2.57 degrees, 3.63 degrees, At 4.44 degrees and 5.15 degrees, the wavelength range from 1280 to 1285nm can be realized.

There is an inclination angle between the extension direction of the optical waveguide of the grating area of the seventh laser, the eighth laser, the ninth laser, and the tenth laser and the optical waveguide of the gain area, due to the inclined grating (or the optical waveguide of the inclined grating area) The roughness of the side of the optical waveguide in the grating area increases, and the loss becomes larger, and the loss becomes larger with the increase of the angle. Simultaneously, because the extension direction of the optical waveguide in the gain region is inconsistent with the extension direction of the optical waveguide in the grating region, the loss in the tail region (that is, the region where the optical waveguide in the gain region is connected to the optical waveguide in the grating region) will increase with the increase of the angle. get bigger. Therefore, although the optical waveguide in the grating area is inclined relative to the optical waveguide in the gain area, although the equivalent grating period can be increased, it will cause the loss of the optical waveguide in the grating area to increase, the starting current of the device will increase, and the power will decrease. Since this application has a lower limit requirement for power, the tilt angle cannot be increased all the time. After repeated experiments, the tilt angles of channels 6, 7, 8, and 9 are designed to be 2.57 degrees, 3.63 degrees, 4.44 degrees, and 5.15 degrees, and the equivalent grating period changes are 1947.09A, 1949.05A, 1951.01A, 1953.03A , can achieve wavelength changes from 1280nm to 1285nm.

The first laser, the second laser, the third laser, the fourth laser, the fifth laser, the sixth laser, the seventh laser, the eighth laser, the ninth laser, and the tenth laser The optical waveguide and the grating area of the 10 lasers The relationship between the angle between the optical waveguides in the gain area, the injection current parameters in the grating area, and the output wavelength is shown in Table 1.

Table 1 The relationship between the angle between the optical waveguide in the grating area and the optical waveguide in the gain area of the laser, the injection current parameter and the output wavelength

aisle	Optical waveguide angle (°)	Injection current (mA)	Output wavelength(nm)
0	0	40	1274.96

1	0	25	1276.18
2	0	9.5	1277.10
3	0	5.4	1278.30
4	0	2	1279.40
5	0	0.3	1280.58
6	2.57	0.3	1281.52
7	3.63	0.3	1282.62
8	4.44	0.2	1283.76
9	5.15	0.5	1284.92

As shown in Table 1, the distance between the extending direction of the optical waveguide in the grating region of the first laser, the second laser, the third laser, the fourth laser, the fifth laser and the sixth laser and the extending direction of the optical waveguide in the gain region The included angles are all 0 degrees, and the extension direction of the optical waveguide in the grating area and the extension direction of the optical waveguide in the gain area are on the same horizontal line, that is, the first laser, the second laser, the third laser, the fourth laser, the fifth laser and The sixth laser is not set as an inclined optical waveguide, but modulates beams of different wavelengths by changing the magnitude of the Bragg reflection energization signal applied to the grating area, the first laser, the second laser, the third laser, the fourth laser, The currents of the fifth laser and the sixth laser injected into the optical waveguide of the grating area are 40mA, 25mA, 9.5mA, 5.4mA, 2mA, 0.3mA, and the corresponding output wavelengths are 1274.96nm, 1276.18nm, 1277.10nm, 1278.30 nm, 1279.40nm, 1280.58nm; realized to increase the wavelength modulation range of the Bragg grating tailed Fabry-Perot cavity to the short wavelength (1275nm-1280nm) direction.

The included angles between the extension direction of the optical waveguide in the grating area of the seventh laser, the eighth laser, the ninth laser, and the tenth laser and the extension direction of the optical waveguide in the gain area are 2.57 degrees, 3.63 degrees, 4.44 degrees and 5.15 degrees in sequence, That is, the seventh laser, the eighth laser, the ninth laser, and the tenth laser are all set as oblique waveguides, and the corresponding output wavelengths are 1281.52nm, 1282.62nm, 1283.76nm, and 1284.92nm; the increase in the direction of long wavelength (1280nm-1285nm) wavelength modulation range.

In this way, each laser on the laser chip can finally realize a wavelength modulation range of 10nm.

Fig. 10 is a schematic diagram of specific wavelength modulation of a 10-channel laser of a light source assembly according to some embodiments. As shown in Fig. The wavelength changes corresponding to the laser, the second laser, the third laser, the fourth laser, the fifth laser and the sixth laser, the seventh laser, the eighth laser, the ninth laser and the tenth laser, that is, channel 0 and channel 1 , Channel 2, Channel 3, Channel 4, Channel 5, Channel 6, Channel 7, Channel 8, and Channel 9 corresponding to the wavelength change of the laser.

In the light source assembly and the optical module provided by some embodiments of the present disclosure, at least two lasers are arranged on the surface of the laser chip, one of the lasers includes a gain region and a grating region, and the first output of different wavelengths is output by changing the magnitude of the current injected into the grating region. light beam, and then increase the wavelength modulation range of the grating itself to the short wavelength direction relative to the target wavelength; the other laser includes a gain region and a grating region, and the extension direction of the optical waveguide in the grating region is relative to the extension direction of the optical waveguide in the gain region Tilting and forming a tilt angle, by changing the size of the tilt angle to output second light beams with different wavelengths, and by adopting a slope waveguide design, the wavelength modulation range can be increased in the long wavelength direction relative to the target wavelength. The present invention can realize the integration of lasers at the level of laser chips, realize the simultaneous operation of multiple lasers on a single chip, improve the integration density of chips, and realize precise modulation of wavelength through carrier injection changes and inclined waveguides.

The light source assembly in some embodiments of the present disclosure can be used as a light source of an optical module with a silicon optical structure, and the optical signal emitted from the Fabry Perot resonant cavity tailed by the grating region of the light source assembly is coupled to the optical entrance of the silicon optical chip. The optical module provided by some embodiments of the present disclosure realizes the integration of multiple lasers at the chip level, realizes simultaneous output of beams of different wavelengths by multiple lasers on the same laser chip, improves the integration of light sources and realizes precise modulation of wavelengths.

Those skilled in the art will appreciate that the disclosed scope of the present invention is not limited to the specific embodiments described above, and some elements of the embodiments can be modified and replaced without departing from the spirit of the present disclosure. The scope of the present disclosure is limited by the appended claims.

Claims (15)

1. A light source assembly, comprising:

   laser chip;

   A plurality of lasers are arranged on the surface of the laser chip, each laser includes a gain region and a grating region, and the gain region and the grating region each have an optical waveguide; wherein the plurality of lasers include:

   A first group of lasers, the grating region of each laser in the first group of lasers is configured to receive an external current to output a first beam of corresponding wavelength;

   The second group of lasers, the optical waveguide of each laser in the second group of lasers has an inclination angle between the optical waveguide of the grating area and the optical waveguide of the gain area, so as to output a second beam of corresponding wavelength, and the wavelength of the second beam is the same as that of the gain area. The wavelengths of the first light beams are different.
2. The light source assembly according to claim 1, wherein the grating regions of the plurality of lasers are each terminated with a Fabry-Perot resonator.
3. The light source assembly according to claim 1, wherein the material of the optical waveguide in the grating region comprises InGaAsP with a photoluminescence peak of 1170nm.
4. The light source assembly according to claim 3, wherein the grating area further includes a grating, the grating is stacked with the optical waveguide, and the material of the grating includes InGaAsP with a photoluminescence peak of 1150nm.
5. The light source assembly of claim 4, wherein the grating is a distributed Bragg reflection grating.
6. The light source assembly according to claim 1, wherein the plurality of lasers comprises 10 lasers, and the distance between adjacent lasers is 250 μm.
7. The light source assembly according to claim 6, wherein the first group of lasers includes 6 lasers, and the extending direction of the optical waveguide in the grating region of each laser is the same as the extending direction of the optical waveguide in the gain region;

   The grating regions of the six lasers receive different external currents to output first light beams with different wavelengths.
8. The light source assembly according to claim 7, wherein the second group of lasers includes four lasers, and the inclination angles between the optical waveguides in the grating region and the optical waveguides in the gain region of the four lasers are different to output different wavelength of the second beam.
9. The light source assembly according to claim 8, wherein the inclination angles between the optical waveguides in the grating area and the optical waveguides in the gain area of the four lasers are 2.57 degrees, 3.63 degrees, 4.44 degrees and 5.15 degrees in sequence.
10. The light source assembly according to claim 1, further comprising a plurality of signal lasers and a plurality of photodetectors;

    The plurality of signal lasers and the plurality of photodetectors are disposed on the surface of the laser chip for active alignment.
11. The light source assembly according to claim 1, wherein the plurality of lasers further comprises a third group of lasers, the grating area of each laser in the third group of lasers further comprises a temperature regulator, and the temperature regulator is arranged at The optical waveguide is configured to regulate the temperature of the grating region.
12. An optical module, comprising:

    circuit board;

    The light source assembly according to claim 1, connected to the circuit board;

    The silicon photonics chip is electrically connected to the circuit board and optically connected to the light source component, configured to receive the light beam emitted by the light source component.
13. The optical module according to claim 12, wherein the circuit board includes a through hole, and the light source component and the silicon photonic chip are arranged in the through hole.
14. The optical module according to claim 13, further comprising a substrate, the substrate is arranged in the through hole, and the silicon photonic chip and the light source assembly are arranged on the substrate.
15. The optical module according to claim 14, wherein the material of the substrate comprises silicon or glass.

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