Laser chip and optical module

Abstract

The laser chip and the optical module provided by the invention comprise a circuit board, a coherent optical component and a light source, the coherent optical component is used for modulating and demodulating an optical signal, and the light source provides light without carrying data for the coherent optical component, so that the coherent optical component modulates the optical signal according to the light without carrying data. The light source comprises a laser chip, the laser chip comprises a gain area, a first grating area and a second grating area, the first grating area and the second grating area are located on the two sides of the gain area respectively, the second grating area comprises a continuous non-etching section and an interval etching section which are connected with each other, the continuous non-etching section does not generate refractive index difference, and the interval etching section does not generate refractive index difference. According to the invention, on the premise that the length of the first grating region is kept unchanged, the continuous non-etching sections are arranged, so that the reflectivity of the first grating region is reduced, and on the premise that the line width is ensured, the light emitting power is increased.

Description

Technical Field

[0001] The present application relates to the field of optical communication technology, and in particular to a laser chip and an optical module. Background Art

[0002] In the field of high-speed coherent optical communications, since 50 GHz or even narrower channel widths are used for communication, high quality requirements are placed on the line width of optical signals generated by laser chips, such as requiring the line width of optical signals to be as small as possible less than 100 kHz.

[0003] Distributed Bragg Reflector (DBR) lasers have the characteristics of narrow line width and wide wavelength tunable range, and their application range is becoming more and more extensive. In order to pursue higher output optical power, current DBR lasers usually shorten the length of the laser resonant cavity to reduce the reflectivity and obtain higher output optical power. However, when the length of the resonant cavity is shortened, the line width becomes wider and the line width cannot be guaranteed, thus failing to meet the line width quality requirements of the optical signal. Summary of the invention

[0004] The present application provides a laser chip and an optical module to increase the output optical power while ensuring the line width.

[0005] The present application provides a laser chip, comprising:

[0006] A substrate, the surface of which includes a first partition, a second partition and a third partition, wherein the second partition and the third partition are respectively arranged on both sides of the first partition;

[0007] A gain region is provided on the surface of the first sub-region, and the gain region includes, from bottom to top, an etching stop layer, a lower limiting layer, an active layer, an upper limiting layer, a spacer layer, and a contact layer along the surface of the first sub-region; the gain region is used to generate gain light according to the injected carriers;

[0008] A first grating region is provided on the surface of the second sub-region, and the first grating region includes, from bottom to top along the surface of the second sub-region: a waveguide layer, a grating layer, a spacer layer, and a contact layer;

[0009] A second grating region is arranged on the surface of the third sub-region, and the second grating region includes, from bottom to top along the surface of the third sub-region: a waveguide layer, a grating layer, a spacer layer, and a contact layer, wherein the grating layer includes a plurality of grating periods, and the grating period includes continuous non-etched segments and spaced etched segments connected to each other, and the spaced etched segments include etched areas and non-etched areas arranged at intervals; the non-etched segments and the non-etched areas are used to not reflect the gain light, and the etched areas are used to reflect the gain light, and the sum of the lengths of the non-etched segments and the non-etched areas is greater than the length of the etched area, thereby reducing the reflectivity of the second grating region.

[0010] The sum of the lengths of the non-etched areas is greater than the length of the etched areas, thereby reducing the reflectivity of the second grating area.

[0011] In the laser chip and optical module provided by the present application, the laser chip includes a substrate, a gain region, a first grating region and a second grating region. The surface of the substrate includes a first partition, a second partition and a third partition, the second partition and the third partition are respectively arranged on both sides of the first partition, the gain region is arranged on the surface of the first partition, the first grating region is arranged on the surface of the second partition, and the second grating region is arranged on the front surface of the third partition, then the first grating region and the second grating region are respectively arranged on both sides of the gain region. The gain region is used to generate gain light according to the injected carriers, and the first grating region and the second grating region are used to tune the wavelength of the laser. The first grating region includes: a waveguide layer, a grating layer, a spacer layer, and a contact layer from bottom to top along the surface of the second partition. The second grating region includes, from bottom to top, along the surface of the third sub-region: a waveguide layer, a grating layer, a spacer layer, and a contact layer, wherein the grating layer includes interconnected continuous non-etched segments and spaced etched segments, the spaced etched segments include spaced etched areas and non-etched areas, the continuous non-etched segments and the non-etched areas will not produce a refractive index difference, will not reflect the gain light, and the sum of the lengths of the non-etched segments and the non-etched areas is greater than the length of the etched areas, so relative to all uniformly etched grating regions, the second grating region in the present application has a lower reflectivity, thereby increasing the output light power, and the length of the second grating region in the present application remains unchanged, thereby ensuring the line width, so the second grating region of the present application reduces its reflectivity by setting a continuous non-etched segment while keeping the length unchanged, so that the present application achieves an increase in the output light power while ensuring the line width. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the present disclosure, the following briefly introduces the drawings used in some embodiments of the present disclosure. Obviously, the drawings described below are only drawings of some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can also be obtained based on these drawings. In addition, the drawings described below 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 the signal, etc.

[0013] Figure 1 is a partial architecture diagram of an optical communication system according to some embodiments;

[0014] Figure 2 is a partial structural diagram of a host computer according to some embodiments;

[0015] Figure 3 is a structural diagram of an optical module according to some embodiments;

[0016] Figure 4 is an exploded view of an optical module according to some embodiments;

[0017] Figure 5 is a diagram of the internal structure of an optical module according to some embodiments;

[0018] Figure 6 is a structural diagram of a light source according to some embodiments;

[0019] Figure 7 is a diagram of the internal structure of a light source according to some embodiments;

[0020] Figure 8 is a structural diagram of a laser chip according to some embodiments;

[0021] Fig. 9 is a partial structural diagram of a laser chip according to some embodiments;

[0022] Fig.10 is a further partial structural diagram of a laser chip according to some embodiments;

[0023] Fig.11 is a structural diagram of a grating period of a second grating region according to some embodiments;

[0024] Fig.12 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 1 ;

[0025] Fig.13 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 2 ;

[0026] Fig.14 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 3 . DETAILED DESCRIPTION

[0027] In optical communication technology, in order to establish information transmission between information processing devices, it is necessary to load information onto light and use the propagation of light to achieve information transmission. Here, the light loaded with information is an optical signal. When optical signals are transmitted in information transmission equipment, the loss of optical power can be reduced, so high-speed, long-distance, and low-cost information transmission can be achieved. The signals that information processing equipment can recognize and process are electrical signals. Information processing equipment usually includes optical network terminals (Optical Network Unit, ONU), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., and information transmission equipment usually includes optical fibers and optical waveguides.

[0028] The optical module can realize the mutual conversion between optical signals and electrical signals between information processing equipment and information transmission equipment. For example, at least one of the optical signal input end or the optical signal output end of the optical module is connected to an optical fiber, and at least one of the electrical signal input end or the electrical signal output end of the optical module is connected to an optical network terminal; the first optical signal from the optical fiber is transmitted to the optical module, and the optical module converts the first optical signal into a first electrical signal, and transmits the first electrical signal to the optical network terminal; the second electrical signal from the optical network terminal is transmitted to the optical module, and the optical module converts the second electrical signal into a second optical signal, and transmits the second optical signal to the optical fiber. Since multiple information processing devices can transmit information through electrical signals, at least one of the multiple information processing devices needs to be directly connected to the optical module, and all information processing devices do not need to be directly connected to the optical module. Here, the information processing device directly connected to the optical module is called the upper computer of the optical module. In addition, the optical signal input end or the optical signal output end of the optical module can be called an optical port, and the electrical signal input end or the electrical signal output end of the optical module can be called an electrical port.

[0029] Figure 1 FIG. 1 is a partial structural diagram of an optical communication system according to some embodiments. Figure 1 As shown, the optical communication system mainly includes a remote information processing device 1000 , a local information processing device 2000 , a host computer 100 , an optical module 200 , an optical fiber 101 and a network cable 103 .

[0030] One end of the optical fiber 101 extends toward the remote information processing device 1000, and the other end of the optical fiber 101 is connected to the optical module 200 through the optical port of the optical module 200. The optical signal can be totally reflected in the optical fiber 101, and the propagation of the optical signal in the total reflection direction can almost maintain the original optical power. The optical signal undergoes multiple total reflections in the optical fiber 101 to transmit the optical signal from the remote information processing device 1000 to the optical module 200, or to transmit the optical signal from the optical module 200 to the remote information processing device 1000, thereby realizing long-distance, low-power loss information transmission.

[0031] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 are detachably connected or fixedly connected to the optical module 200. The host computer 100 is configured to provide data signals to the optical module 200, receive data signals from the optical module 200, or monitor or control the working state of the optical module 200.

[0032] The host computer 100 includes a substantially rectangular housing and an optical module interface 102 disposed on the housing. The optical module interface 102 is configured to connect to the optical module 200 so that the host computer 100 and the optical module 200 establish a unidirectional or bidirectional electrical signal connection.

[0033] The host computer 100 also includes an external electrical interface, which can be connected to an electrical signal network. For example, the external electrical interface includes a Universal Serial Bus (USB) interface or a network cable interface 104, and the network cable interface 104 is configured to access the network cable 103 so that the host computer 100 establishes a unidirectional or bidirectional electrical signal connection with the network cable 103. One end of the network cable 103 is connected to the local information processing device 2000, and the other end of the network cable 103 is connected to the host computer 100, so as to establish an electrical signal connection between the local information processing device 2000 and the host computer 100 through the network cable 103. For example, the third electrical signal sent by the local information processing device 2000 is transmitted to the host computer 100 through the network cable 103, and the host computer 100 generates a second electrical signal according to the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200, and the optical module 200 converts the second electrical signal into a second optical signal, and transmits the second optical signal to the optical fiber 101, and the second optical signal is transmitted to the remote information processing device 1000 in the optical fiber 101. For example, the first optical signal from the remote information processing device 1000 is transmitted through the optical fiber 101, and the first optical signal from the optical fiber 101 is transmitted to the optical module 200, and the optical module 200 converts the first optical signal into a first electrical signal, and the optical module 200 transmits the first electrical signal to the host computer 100, and the host computer 100 generates a fourth electrical signal according to the first electrical signal, and transmits the fourth electrical signal to the local information processing device 2000. It should be noted that the optical module is a tool for realizing the mutual conversion between optical signals and electrical signals. During the conversion process between the optical signals and electrical signals, the information does not change, but the encoding and decoding methods of the information can change.

[0034] In addition to the optical network terminal, the host computer 100 also includes an optical line terminal (OLT), an optical network device (ONT), or a data center server.

[0035] Figure 2 FIG. 1 is a partial structural diagram of a host computer according to some embodiments. In order to clearly show the connection relationship between the optical module 200 and the host computer 100, Figure 2 Only the structure of the host computer 100 related to the optical module 200 is shown. Figure 2 As shown, the host computer 100 further includes a PCB circuit board 105 disposed in the housing, a cage 106 disposed on the surface of the PCB circuit board 105, a heat sink 107 disposed on the cage 106, and an electrical connector disposed inside the cage 106. The electrical connector is configured to access the electrical port of the optical module 200; the heat sink 107 has a protruding structure such as fins to increase the heat dissipation area.

[0036] The optical module 200 is inserted into the cage 106 of the host computer 100, and the cage 106 fixes the optical module 200. The heat generated by the optical module 200 is transferred to the cage 106 and then diffused through the heat sink 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 host computer 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.

[0037] Figure 3 is a structural diagram of an optical module according to some embodiments, Figure 4 FIG. 1 is an exploded view of an optical module according to some embodiments. Figure 3 and Figure 4 As shown, the optical module 200 includes a shell, a circuit board 300 disposed in the shell, a light source 900 , and a coherent optical component 1100 .

[0038] The housing comprises an upper housing 201 and a lower housing 202 . The upper housing 201 covers the lower housing 202 to form the housing having two openings 204 and 205 . The outer contour of the housing is generally a square body.

[0039] In some embodiments, 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 arranged perpendicular to the bottom plate 2021; the upper shell 201 includes a cover plate 2011, and the cover plate 2011 covers the two lower side plates 2022 of the lower shell 202 to form the above-mentioned shell.

[0040] In some embodiments, 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 vertically arranged with the bottom plate 2021; the upper shell 201 includes a cover plate 2011 and two upper side plates located on both sides of the cover plate 2011 and vertically arranged with the cover plate 2011, and the two upper side plates are combined with the two lower side plates 2022 to realize that the upper shell 201 covers the lower shell 202.

[0041] 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 be inconsistent with the length direction of the optical module 200. For example, the opening 204 is located at the end of the optical module 200 ( Figure 3 The opening 205 is also located at the end of the optical module 200 ( Figure 3Alternatively, the opening 204 is located at the end of the optical module 200, and the opening 205 is located at the side of the optical module 200. The opening 204 is an electrical port, and the gold finger 301 of the circuit board 300 extends from the opening 204 and is inserted into the electrical connector of the host computer 100; the opening 205 is an optical port, which is configured to access the external optical fiber 101, so that the optical fiber 101 is connected to the light source 900 and the coherent optical component 1100 in the optical module 200.

[0042] The upper housing 201 and the lower housing 202 are combined to facilitate the installation of the circuit board 300, the light source 900, the coherent optical component 1100, etc. into the housing, and the upper housing 201 and the lower housing 202 can encapsulate and protect the above components. In addition, when assembling the circuit board 300, the light source 900, the coherent optical component 1100, etc., it is convenient to deploy the positioning components, heat dissipation components, and electromagnetic shielding components of these components, which is conducive to automated production.

[0043] In some embodiments, the upper shell 201 and the lower shell 202 are made of metal materials to facilitate electromagnetic shielding and heat dissipation.

[0044] In some embodiments, the optical module 200 further includes an unlocking component 600 located outside its housing. The unlocking component 600 is configured to achieve a fixed connection between the optical module 200 and the host computer, or to release the fixed connection between the optical module 200 and the host computer.

[0045] For example, the unlocking component 600 is located on the outside of the two lower side plates 2022 of the lower housing 202, and includes a snap-fit ​​component that matches the cage 106 of the host computer 100. When the optical module 200 is inserted into the cage 106, the snap-fit ​​component of the unlocking component 600 fixes the optical module 200 in the cage 106; when the unlocking component 600 is pulled, the snap-fit ​​component of the unlocking component 600 moves accordingly, thereby changing the connection relationship between the snap-fit ​​component and the host computer, so as to release the fixation of the optical module 200 and the host computer, so that the optical module 200 can be pulled out of the cage 106.

[0046] The circuit board 300 includes circuit traces, electronic components and chips, etc. The electronic components and chips are connected according to the circuit design through the circuit traces to realize the functions of power supply, electrical signal transmission and grounding. The electronic components may include capacitors, resistors, transistors, metal-oxide-semiconductor field-effect transistors (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET), etc. The chips may include microcontroller units (Microcontroller Unit, MCU), laser driver chips, transimpedance amplifiers (Transimpedance Amplifier, TIA), limiting amplifiers (Limiting amplifier), clock and data recovery chips (Clock and Data Recovery, CDR), power management chips, digital signal processing (Digital Signal Processing, DSP) chips.

[0047] The circuit board 300 is generally a rigid circuit board. Due to its relatively hard material, the rigid circuit board can also realize the load-bearing function. For example, the rigid circuit board can stably carry the above-mentioned electronic components and chips; the rigid circuit board can also be inserted into the electrical connector in the cage 106 of the host computer 100.

[0048] The circuit board 300 also includes a gold finger 301 formed on the end surface thereof. The gold finger 301 is composed of a plurality of independent pins. The circuit board 300 is inserted into the cage 106, and the gold finger 301 is connected to the electrical connector in the cage 106. The gold finger 301 can be provided on only one side of the circuit board 300 (e.g. Figure 4 The upper surface shown in the figure) can also be set on the upper and lower surfaces of the circuit board 300 to provide more pins, so as to adapt to occasions where the number of pins is large. The gold finger 301 is configured to establish an electrical connection with the host computer to achieve power supply, grounding, two-wire synchronous serial (Inter-Integrated Circuit, I2C) signal transmission, data signal transmission, etc. Of course, flexible circuit boards are also used in some optical modules. Flexible circuit boards are generally used in conjunction with rigid circuit boards to supplement rigid circuit boards.

[0049] Figure 5 FIG. 1 is a diagram showing the internal structure of an optical module according to some embodiments. Figure 5 As shown, in some embodiments, a light source 900 and a coherent optical component 1100 are respectively disposed on the surface of the circuit board 300. The coherent optical component 1100 includes an optical modulation chip inside, which is used to modulate and demodulate optical signals. Exemplarily, the optical modulation chip is a silicon photonic chip or a thin-film lithium niobate chip.

[0050] The optical modulation chip itself does not have a light source. The light source 900 is used as an external light source of the optical modulation chip. The light source 900 emits light from the side, and the light it emits enters the optical modulation chip, so that the optical signal is modulated by the modulator built into the optical modulation chip. The external optical signal enters the optical modulation chip and is then coherently demodulated with the local oscillator light to achieve demodulation of the optical signal.

[0051] Figure 6 FIG. 1 is a structural diagram of a light source according to some embodiments. Figure 6 As shown, in some embodiments, the light source 900 can be in the form of a laser module, which includes a packaging cavity 910 and an internal optical fiber adapter 920. A laser chip is integrated inside the packaging cavity 910. The laser chip is used to generate a light beam of a specific wavelength. The generated light beam is transmitted to the inside of the coherent optical component 1100 via the internal optical fiber adapter 920 to modulate the optical signal.

[0052] Figure 7 FIG. 9 is an internal structure diagram of a light source according to some embodiments. In some embodiments, the light source 900 is in the form of a laser module, and illustratively, the laser module is a wavelength tunable laser module.

[0053] In some embodiments, the wavelength tunable laser module includes optical elements such as a laser chip 930, a first etalon 940, a phase shifter 950, and a second etalon 960. The light beam output by the laser chip 930 enters the first etalon 940, and the wavelength that can pass through the first etalon 940 and the second etalon 960 is screened out through the combination of the first etalon 940 and the second etalon 960. Specifically, by heating the first etalon 940 and the second etalon 960, the required wavelength (target wavelength) can be selected through the vernier effect of the two to achieve wavelength tuning; the resonant cavity of the tunable laser is long, and there are many cavity modes that may oscillate; the filter transmission spectrum only allows one of the cavity modes to have a lower loss and form a laser oscillation output; because the cavity mode is easily drifted due to the influence of temperature, stress, etc., and the output wavelength is related to the cavity mode, which leads to the drift of the output wavelength, it is necessary to lock the output wavelength of the laser chip. In the embodiment of the present application, the phase shifter 950 is used to lock the wave. By changing the temperature of the phase shifter 950 to change the refractive index of the phase shifter 950, the optical length of the phase shifter 950 is changed, and then the cavity length of the resonant cavity is changed to lock the cavity length of the resonant cavity, and accordingly lock the cavity mode of the resonant cavity, thereby locking the wavelength.

[0054] In the field of high-speed coherent optical communication, since a 50 GHz or even narrower channel width is used for communication, the line width quality of the optical signal generated by the laser chip 930 is required to be relatively high, such as requiring the line width of the optical signal to be as small as possible less than 100 KHz.

[0055] In some embodiments of the present application, a laser chip structure is provided to reduce the photoelectric interaction and light absorption effect, thereby reducing low-frequency phase noise and narrowing the line width.

[0056] Figure 8 is a structural diagram of a laser chip according to some embodiments; Fig. 9 FIG. 1 is a partial structural diagram of a laser chip according to some embodiments. Fig. 9 for Figure 8 The local structure diagram of Figure 8-Figure 9 As shown, in some embodiments of the present application, the laser chip 930 is a DBR laser chip, and the DBR laser chip uses the screening function of the Labuge reflection grating for a specific wavelength to achieve the output of a specific wavelength. In some embodiments, the laser chip 930 includes a substrate 930a, which is divided along the surface of the substrate 930a to include: a first partition 930a1, a second partition 930a2, and a third partition 930a3, and the second partition 930a2 and the third partition 930a3 are respectively located on both sides of the first partition 930a1. A gain region 931 is grown along the surface of the first partition 930a1. The gain region 931 is an active region for generating gain. In order to make the gain region 931 generate laser, carriers are electrically injected into the gain region 931. At this time, the stimulated radiation in the gain region 931 causes discrete electron-hole pairs (eh pairs) to recombine and generate photons, thereby effectively converting the electrically injected carriers into photons to generate gain light. By changing the current injected into the grating area, the effective refractive index of the grating area can be changed, thereby changing the resonant lasing wavelength of the laser chip and realizing the wavelength tuning function.

[0057] In some embodiments, in order to increase the tuning range of the wavelength, a first grating region 932 and a second grating region 933 are formed on the surfaces of the second sub-area 930a2 and the third sub-area 930a3, respectively. For example, the first grating region 932 is formed along the surface of the second sub-area 930a2, and the second grating region 933 is formed along the surface of the third sub-area 930a3. Since the second sub-area 930a2 and the third sub-area 930a3 are respectively located on both sides of the first sub-area 930a1, the first grating region 932 and the second grating region 933 are respectively arranged on both sides of the gain region 931. Current is injected into region 933 to change the effective refractive index inside each grating, and the reflection peaks of the first grating region 932 and the second grating region 933 will move along the same wavelength direction, such as moving toward the long wavelength direction. Since the spacing between the reflection peaks of the first grating region 932 and the second grating region 933 is different, each time the reflection peaks of the first grating region 932 and the second grating region 933 are matched at different peak values, a new wavelength mode will be generated accordingly. With the emergence of more matching modes, the output wavelength range of the laser chip is expanded, so that by jointly tuning the first grating region 932 and the second grating region 933, the tuning range of the wavelength can be increased.

[0058] In some embodiments, a fourth partition 930a4 is provided between the second partition 930a2 and the first partition 930a1 of the substrate 930a, and a phase zone 934 is grown along the surface of the fourth partition 930a4. By injecting different currents into the phase zone 934, the effective refractive index of the material is changed, thereby changing the wavelength mode in the resonant cavity, providing a more precise wavelength tuning capability for the output of the laser chip. Exemplarily, the reflection peaks matched by the first grating region 932 and the second grating region 933 contain multiple equally spaced longitudinal modes. When the current injected into the phase zone 934 is increased, the longitudinal mode moves, and the output wavelength moves slightly, thereby making the wavelength tuning more precise.

[0059] In some embodiments, the phase region 934 and the second grating region 933 are respectively arranged on both sides of the gain region 931, the phase region 934 is located on one side of the gain region 931, the second grating region 933 is located on the other side of the gain region 931, and the first grating region 932 is located on one side of the phase region 934, that is, the first grating region 932, the phase region 934, the gain region 931, and the second grating region 933 are arranged in sequence to form a resonant cavity. The end face of the first grating region 932 has a high reflectivity, and the end face of the second grating region 933 has a high transmittance, so the gain light generated by the gain region 931 oscillates back and forth between the phase region 934, the first grating region 932, and the second grating region 933, thereby generating laser light, which is transmitted along the light emitting direction of the laser chip 930. Exemplarily, the gain light generated by the gain zone 931 is transmitted from the phase zone 934 to the first grating zone 932, re-enters the phase zone 934 after being reflected by the first grating zone 932, and is then transmitted to the gain zone 931 and the second grating zone 933 in sequence, repeatedly oscillating in the resonant cavity, forming positive feedback to generate laser, which is emitted from the second grating zone 933.

[0060] In some embodiments, in order to increase the laser output light power, a semiconductor optical amplifier region (SOA) 935 is formed on one side of the second grating region 933. The SOA has the same epitaxial structure as the gain region 931 and functions to further amplify the photons output from the second grating region 933, thereby increasing the output light power and enhancing the output light signal size of the laser chip.

[0061] In some embodiments, the epitaxial structure of the gain region 931 includes, from bottom to top, along the surface of the first subarea 930a1 of the substrate: an etching stop layer 9317, a lower limiting layer 9316, an active layer 9315, an upper limiting layer 9314, a waveguide layer 9313, a spacer layer 9312, and a contact layer 9311. Among them, the contact layer 9311 is an ohmic contact layer. The active layer 9315 adopts a multi-quantum well structure to improve the ability of the active region to collect carriers and increase the ability of radiation recombination. As the number of quantum wells increases and the number of activated substances increases, the optical gain gradually increases, thereby increasing the output optical power. The upper limiting layer 9314 and the lower limiting layer 9316 are respectively located on both sides of the active layer 9315, and are mainly used to provide a heterojunction to better regulate and limit the recombination area of ​​the carriers, and to limit the light to the active layer 4215. At the same time, the refractive index of the waveguide layer 4213 is smaller than the refractive indexes of the upper confinement layer 4214 , the lower confinement layer 4216 , and the active layer 4215 , thereby better confining the photons within the active layer 4215 .

[0062] Selective etching is one of the key processes for preparing laser chips, and its methods include wet etching. Wet etching uses a chemical reaction between a corrosive solution and the material to be etched. By selecting a suitable chemical etching solution, it is possible to selectively react with the etching material or not react. The etching stop layer 9317 is a chemical etching solution that does not react with the etching material, thereby avoiding etching, to effectively control the depth and range of wet etching.

[0063] In some embodiments, the epitaxial structure of the first grating region 932 includes, from bottom to top along the surface of the second sub-region 930a2 of the substrate: a first hollowed-out region 9325, a waveguide layer 9324, a grating layer 9323, a spacer layer 9322, and a contact layer 9321. The grating layer 9323 and the waveguide layer 9324 are located on one side of the active layer 9315, so the light field distribution of the grating layer 9323 and the waveguide layer 9324 is relatively strong.

[0064] In some embodiments, the epitaxial structure of the second grating region 933 includes, from bottom to top along the surface of the third sub-region 930a3 of the substrate: a second hollowed-out region 9335, a waveguide layer 9334, a grating layer 9333, a spacer layer 9332, and a contact layer 9331. The epitaxial structure of the second grating region 933 is the same as the epitaxial structure of the first grating region 932.

[0065] In some embodiments, the epitaxial structure of the phase zone 934 includes, from top to bottom along the fourth partition 930a4 of the substrate: a third hollowed-out region 9344 , a waveguide layer 9343 , a spacer layer 9342 , and a contact layer 9341 .

[0066] In some embodiments of the present application, the first hollowed-out region 9325 is connected to the third hollowed-out region 9344 and is located on one side of the etch stop layer 9317 in the gain region 931 , and the second hollowed-out region 9335 is located on the other side of the etch stop layer 9317 .

[0067] In some embodiments, a heating layer is formed above the contact layer 9321 of the first grating region 932. Exemplarily, the heating layer is a TaN heating layer. A protective layer is formed above the heating layer. Exemplarily, the protective layer is a SiO2 protective layer, and the protective layer is used to wrap the heating layer. By electrically heating the heating layer, heat is transferred toward the grating layer 9323 and the waveguide layer 9324, thereby heating the grating layer 9323 and the waveguide layer 9324, changing the effective refractive index of the material, thereby achieving the purpose of wavelength tuning. The provision of the first hollowed-out area 9325 can reduce the dissipation of heat, so that the heat is concentrated on the grating layer 9323 and the waveguide layer 9324, thereby effectively heating the grating layer 9323 and the waveguide layer 9324. Similarly, when the second grating region 933 is heated, the second hollowed-out region 9335 is also arranged so that the heat is concentrated in the grating layer 9333 and the waveguide layer 9334 of the second grating region 933, and the second grating region 933 is effectively heated to achieve the purpose of wavelength tuning. The third hollowed-out region 9344 also functions in the same manner.

[0068] After the SiO2 protective layer wraps the TaN heating layer, the temperature of the middle suspended area can be raised by electrical heating, thereby changing the refractive index of the DBR grating area to achieve the purpose of wavelength tuning. This suspended area has no direct heat conduction channel with the surrounding semiconductor materials, so it does not affect the temperature and refractive index of the gain area and SOA area.

[0069] In some embodiments, the passive waveguide layer of the first grating region 932 and the second grating region 933 is a semiconductor material, which has a conductive property, so the photons generated in the gain region of the laser chip will interact with the semiconductor material photoelectrically, and the mechanism is that the electromagnetic field of the photons will cause the electrons and holes in the semiconductor material to move, forming free carriers, thereby transferring the energy of the electromagnetic field to the electrons and holes, that is, being absorbed by the passive waveguide semiconductor material of the DBR laser chip. Low-frequency phase noise will be generated during the above-mentioned photoelectric interaction and light absorption effect, resulting in a certain degree of broadening of the line width of the optical signal generated by the laser chip, affecting the line width quality of the optical signal.

[0070] In some embodiments of the present application, since the first grating region 932 and the second grating region 933 are respectively located on both sides of the gain region 931, the light field distribution of the first grating region 932 and the second grating region 933 is relatively strong. When the gain light generated by the gain region 931 is transmitted to the first grating region 932 and the second grating region 933, the gain photons will have a strong mutual photoelectric effect with the free carriers inside the first grating region 932 and the second grating region 933, affecting the line width. In the present application, a first doped region is formed in the first grating region 932, and a second doped region is formed in the second grating region 933. Doping substances are added to both the first doping region and the second doping region. The doping substances can consume free carriers, thereby reducing the concentration of free carriers. The lifetime of free carriers is proportional to the concentration of free carriers. Therefore, when doping substances are added, the lifetime of free carriers is reduced, thereby reducing the interaction between free carriers and photons and the light absorption effect, reducing low-frequency phase noise, and thus narrowing the line width; at the same time, when the free carrier concentration is reduced, the resistivity of the semiconductor material in the first grating region 932 and the second grating region 933 increases, and the conductive performance decreases, forming a semi-insulating characteristic, thereby reducing the interaction between free carriers and photons and the light absorption effect, further reducing the low-frequency phase noise, and thus narrowing the line width. For example, the line width is made as small as possible to meet the optical signal line width quality requirements.

[0071] In some embodiments, a phase zone 934 is provided between the first grating zone 932 and the gain zone 931. The phase zone 934 also contains free carriers. When the gain photons are transmitted to the phase zone 934, the gain photons will also undergo photoelectric interactions with the free carriers inside the phase zone 934, thereby affecting the line width. Therefore, in the present application, doping substances are also added to the phase zone 934, and the free carriers are consumed by the doping substances, thereby reducing the concentration of the free carriers, thereby reducing the mutual photoelectric interaction between the gain photons and the free carriers, so as to reduce the line width of the optical signal and meet the optical signal line width quality requirements.

[0072] Fig.10 FIG. 1 is a further partial structural diagram of a laser chip according to some embodiments. Fig.10 for Fig. 9 The structure diagram of Fig.10As shown, in some embodiments, the active layer 9315 in the gain region 931 outputs gain light, and the output gain light field is distributed in the grating layer 9323 and the waveguide layer 9324 of the first grating region 932, and is also distributed in the waveguide layer 9343 of the phase region 934, and is also distributed in the grating layer 9333 and the waveguide layer 9334 of the second grating region 933. Therefore, when doping substances are added in the first grating region 932, the phase region 934 and the second grating region 933, the first doping region is located in the grating layer 9323 and the waveguide layer 9324 of the first grating region 932, the third doping region is located in the waveguide layer 9343 of the phase region 934, and the second doping region is located in the grating layer 9333 and the waveguide layer 9334 of the second grating region 933. Doping substances are added in the above layers to consume free carriers by adding doping substances, thereby achieving line width narrowing.

[0073] Exemplarily, the materials used for the grating layer 9323 , the waveguide layer 9324 of the first grating region 932 , the waveguide layer 9343 of the phase region 934 , the grating layer 9333 , and the waveguide layer 9334 of the second grating region 933 are all InGaAsP semiconductor materials.

[0074] In some embodiments, the doping material may be iron-doped. For example, the doping material is a material containing trivalent iron ions. Fe ions replace In positions to form a neutral trivalent iron oxygen state. The doped trivalent iron ions introduce deep energy level defects in the material band gap. When shallow energy level donors reduce trivalent iron ions, divalent iron is produced. Free carriers are consumed in the reduction process, resulting in a decrease in the equilibrium free carrier concentration, thereby reducing the interaction between free carriers and photons and the light absorption effect, reducing low-frequency phase noise, and thus narrowing the line width. At the same time, this process will cause the resistance of the InGaAsP material to increase. For example, the resistivity exceeds 10 7 Ω.cm, thereby reducing the conductivity of the InGaAsP semiconductor material and forming a semi-insulating property, thereby reducing the interaction between free carriers and photons and light absorption. For example, during MOCVD growth, an iron-containing gas material is doped, and the iron-doped concentration is about (0.5-10)x10 16 cm -3 .

[0075] In some embodiments, the doping material may also be ruthenium. Ruthenium can introduce two defect energy levels in the band gap of semiconductor materials, such as InGaAsP or InP, corresponding to the deeper donor energy level and acceptor energy level, respectively, thereby neutralizing free carriers and holes in the semiconductor material, reducing conductivity, thereby reducing the interaction between free carriers and photons and the light absorption effect, reducing low-frequency phase noise, and thus narrowing the line width.

[0076] In some embodiments of the present application, when the laser is a Y-branch wavelength tunable laser, the two arms of the Y are iron-doped semi-insulating InGaAsP passive optical waveguide DBR grating structures.

[0077] In the present application, the first grating region and the second grating region contain their own free carriers respectively. Since the first grating region and the second grating region are respectively located on both sides of the gain region, the light field distribution of the first grating region and the second grating region is relatively strong. When the gain light generated by the gain region is transmitted to the first grating region and the second grating region, the gain photons will have a photoelectric effect with the free carriers in the first grating region and the second grating region, affecting the line width. In the present application, doping substances are added to the first grating region and the second grating region respectively. The doping substances can consume carriers, thereby reducing the concentration of free carriers. The lifetime of free carriers is proportional to The free carrier concentration is affected by the free carrier lifetime, so when the doping material is added, the free carrier lifetime is relatively small, thereby reducing the interaction between the free carriers and the gain photons and the light absorption effect, reducing the low-frequency phase noise, and thus narrowing the line width; at the same time, when the free carrier concentration in the first grating area and the second grating area is reduced, the resistivity of the semiconductor material in the first grating area and the second grating area becomes larger, the conductivity is reduced, and a semi-insulating characteristic is formed, thereby reducing the interaction between the carriers and the photons and the light absorption effect, further reducing the low-frequency phase noise, and thus narrowing the line width to meet the optical signal line width quality requirements.

[0078] In some embodiments of the present application, the line width and output optical power of an optical signal are often not taken into account at the same time. For example, in order to pursue a higher output optical power, a DBR laser can reduce the reflectivity by shortening the resonant cavity length of the laser to obtain a higher output optical power. However, when the length of the resonant cavity is shortened, the line width becomes wider and the line width cannot be guaranteed, thereby failing to meet the line width quality requirements of the optical signal, resulting in a failure to take into account the line width and output optical power of the optical signal.

[0079] In some embodiments, while ensuring that the length of the resonant cavity remains unchanged, that is, the line width is ensured, by arranging interconnected continuous non-etched segments and spaced etched segments within the grating period of the second grating region 933, the second grating region 933 has a lower reflectivity, thereby increasing the output light power, thereby taking into account both the line width and the output light power of the optical signal.

[0080] Fig.11 FIG. 4 is a structural diagram of a grating period of a second grating region according to some embodiments. Fig.11As shown, in some embodiments of the present application, in order to ensure both line width and high light output power, the grating layer 9333 of the second grating region 933 includes a plurality of grating periods 933a, and one grating period 933a includes interconnected continuous non-etching segments 933b and spaced etched segments 933c, and the spaced etched segments 933c include etched areas and non-etched areas arranged at intervals, and the spaced etched segments 933c are intermittently etched. Exemplarily, the intermittent etching is in the form of uniform etching, and the etching is performed at intervals of a fixed period, thereby achieving uniform etching. In some embodiments, each grating period 933a includes interconnected continuous non-etching segments 933b and spaced etched segments 933c.

[0081] Since no etching is performed in the continuous non-etched section 933b, there is no refractive index difference, so the gain light is not reflected. The non-etched area of ​​the spaced etched section 933c is also not etched, and there is no refractive index difference, so the gain light is not reflected. The etched area of ​​the spaced etched section 933c has a refractive index difference, so the gain light is reflected. Exemplarily, the reflection is weak. In one grating period, the sum of the lengths of the non-etched areas of the continuous non-etched section 933b and the spaced etched section 933c is greater than the length of the etched area of ​​the spaced etched section 933c. Therefore, relative to the grating area that is uniformly etched, the second grating area 933 in the present application has a lower reflectivity, thereby increasing the light output power.

[0082] In some embodiments, the grating period is repeated and covers all positions of the second grating region 933, so that the weak reflection of the gain light by the etched area of ​​each spaced etched segment 933c is accumulated, thereby forming the total reflectivity of the second grating region 933 as required by the design; illustratively, the length ratio of the continuous non-etched segment 933b and the spaced etched segment 933c in the grating period can be fixed.

[0083] In some embodiments, the length of a grating period 933a is equal to the sum of the length of the continuous non-etched segment 933b and the length of the spaced etched segment 933c. For example, the length of the continuous non-etched segment 933b is greater than the length of the spaced etched segment 933c, so that the grating layer 9333 of the second grating region 933 has a lower reflectivity, thereby achieving a higher light output power. At the same time, the length of a grating period 933a remains unchanged relative to the grating layer that is uniformly etched. That is, the continuous non-etched segment 933b and the spaced etched segment 933c are processed within the original grating period. Since the length of the grating layer remains unchanged, the length of the resonant cavity remains unchanged, thereby ensuring the line width. At the same time, due to the setting of the continuous non-etched segment 933b, the reflectivity of the second grating region 933 can be reduced, thereby increasing the light output power. The laser chip of the present application can both ensure the line width and increase the light output power, thereby achieving a balance between the line width and the light output power.

[0084] In some embodiments, the first grating region 932 has a higher reflectivity, and the second grating region 933 has a higher transmittance and a lower reflectivity. The ideal reflectivity of the second grating region 933 is defined as a target reflectivity. The length of the continuous non-etched segment 933b and the length of the interval etched segment 933c can be designed according to the target reflectivity. Exemplarily, the length of the continuous non-etched segment 933b is greater than the length of the interval etched segment 933c; exemplary, the length of the continuous non-etched segment 933b is equal to the length of the interval etched segment 933c; exemplary, the length of the continuous non-etched segment 933b is less than the length of the interval etched segment 933c.

[0085] Exemplarily, when the grating is etched using an electron beam lithography (EBL) grating process, the length L1 of the continuous non-etched segment 933b and the length L2 of the spaced etched segment 933c need to be integer multiples of the electron beam etching spot size Λ0, that is, L1 = m1*Λ0 and L2 = m2*Λ0, where m1 and m2 are integers.

[0086] In some embodiments of the present application, in order to obtain the final comb spectrum design of the second grating region, a non-etched phase shift segment is inserted in the grating period of the second grating region. For example, a non-etched phase shift segment of 1 / 4 wavelength is inserted, and the insertion position of the non-etched 1 / 4 wavelength phase shift segment follows the following formula:

[0087]

[0088] Where I0 is the relative intensity of any value; N is the target wavelength λ in the comb reflectance spectrum k The total number of , k is the wavelength subscript; n is the average effective refractive index of the grating area; z is the relative length position of the grating; Λ k represents the required kth target reflection wavelength λ k The corresponding virtual grating period length satisfies λ k =2nΛ k The relationship between k is an adjustable phase parameter used to adjust the kth target wavelength λ k The intensity of the corresponding spectral reflection peak. It can be seen that the wavelength is related to the period length of the virtual grating. When the period length of the virtual grating is locked, k and phase parameter θ k When the wavelength λ k Then locked.

[0089] In some embodiments, the position of the unetched phase-shift segment is the relative length position of the grating corresponding to when I is equal to 0. Exemplarily, the unetched phase-shift segment is a 1 / 4 wavelength unetched phase-shift segment.

[0090] Fig.12 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 1 .like Fig.12 As shown, in some embodiments, the absolute value of the above I(z) formula will fluctuate as z changes. Whenever the I(z) curve passes through the zero point, that is, when I is equal to 0, Fig.12 At the circled position, the phase changes, and the change in phase affects the period length of the virtual grating, thereby affecting the locking of the target wavelength. The present application adjusts the phase by inserting a 1 / 4 wavelength non-etched phase shift segment, thereby locking the period length of the virtual grating and locking the target wavelength.

[0091] Fig.13 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 2 ; Fig.14 Schematic diagram of the principle of not etching the phase shift segment of a laser chip according to some embodiments Figure 3 In some embodiments, a similar Fig.13 The second grating area can present a similar Fig.14 The reflectance spectrum is a comb spectrum. Fig.12 A 1 / 4 wavelength non-etched phase shift segment is inserted into each of the connections marked 8, 4, 12, 2, 14, 15, etc.

[0092] The optical module provided in the present application includes a circuit board, a coherent optical component, and a light source. The coherent optical component is used to modulate and demodulate optical signals. The light source provides the coherent optical component with light that does not carry data, so that the coherent optical component modulates the optical signal according to the light that does not carry data. Among them, the light source includes a laser chip, and the laser chip includes a gain region, a first grating region and a second grating region. The first grating region and the second grating region are respectively located on both sides of the gain region. The first grating region uses a higher reflectivity to make the gain light emitted by the gain region oscillate back and forth in the resonant cavity. The second grating region includes interconnected continuous non-etched sections and spaced etched sections. The continuous non-etched sections will not produce a refractive index difference, so the gain light will not be reflected. The refractive index in the spaced etched sections changes periodically, so the gain light is reflected. Since the second grating region of the present application includes a continuous non-etched section, the section will not reflect the gain light. Therefore, relative to the grating region that is uniformly etched, the second grating region in the present application has a lower reflectivity, thereby increasing the light output power. Moreover, the length of the second grating region in the present application remains unchanged, so that the line width can be guaranteed. Therefore, the second grating region of the present application reduces its reflectivity by setting a continuous non-etched section while keeping the length unchanged, so that the present application achieves the increase of the light output power under the premise of ensuring the line width.

[0093] In some embodiments of the present application, the second grating region 933 includes interconnected continuous non-etched segments and spaced etched segments, the continuous non-etched segments do not produce a refractive index difference, and thus do not reflect the gain light, the refractive index in the spaced etched segments changes periodically, and thus reflects the gain light, since the second grating region 933 of the present application includes a continuous non-etched segment, the segment does not reflect the gain light, so relative to the grating region that is all uniformly etched, the second grating region in the present application has a lower reflectivity, thereby increasing the output light power. At the same time, the waveguide layer and the grating layer of the first grating region 932 both include a first doped region, the first doped region contains a doping substance, and the first doped region is used to consume the free carriers inside the first grating region through the doping substance; the waveguide layer and the grating layer of the second grating region 933 both include a second doped region, the second doped region contains a doping substance, and the second doped region is used to consume the free carriers inside the second grating region through the doping substance. The phase zone 934 also includes a third doped region, in which there is a doping substance, and the third doped region is used to consume the free carriers inside the phase zone through the doping substance. When the gain photons generated by the gain zone 931 are transmitted to the first grating zone 932, the second grating zone 933, and the phase zone 934, the gain photons will interact with the free carriers in the first grating zone, the second grating zone, and the phase zone 934. Photoelectric interaction and light absorption effect, when the free carriers inside are consumed, the concentration of free carriers is reduced, thereby reducing the mutual photoelectric interaction and light absorption effect between the gain photons and the free carriers, thereby reducing the low-frequency phase noise, thereby narrowing the line width to meet the optical signal line width quality requirements. Therefore, the laser chip of the present application can simultaneously increase the output light power and narrow the line width.

[0094] The above is only a specific embodiment of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any changes or substitutions that can be thought of by any person skilled in the art within the technical scope disclosed in the present disclosure should be included in the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure should be based on the protection scope of the claims.

Claims

1. A laser chip, characterized in that: include: A substrate, the surface of which includes a first partition, a second partition and a third partition, wherein the second partition and the third partition are respectively arranged on both sides of the first partition; A gain region is provided on the surface of the first sub-region, and the gain region includes, from bottom to top, an etching stop layer, a lower limiting layer, an active layer, an upper limiting layer, a spacer layer, and a contact layer along the surface of the first sub-region; the gain region is used to generate gain light according to the injected carriers; A first grating region is provided on the surface of the second sub-region, and the first grating region includes, from bottom to top along the surface of the second sub-region: a waveguide layer, a grating layer, a spacer layer, and a contact layer; A second grating region is arranged on the surface of the third sub-region, and the second grating region includes, from bottom to top along the surface of the third sub-region: a waveguide layer, a grating layer, a spacer layer, and a contact layer, wherein the grating layer includes a plurality of grating periods, and the grating period includes continuous non-etched segments and spaced etched segments connected to each other, and the spaced etched segments include etched areas and non-etched areas arranged at intervals; the non-etched segments and the non-etched areas are used to not reflect the gain light, and the etched areas are used to reflect the gain light, and the sum of the lengths of the non-etched segments and the non-etched areas is greater than the length of the etched area, thereby reducing the reflectivity of the second grating region.

2. The laser chip according to claim 1, characterized in that: In the grating period, the length of the continuous non-etching segment is greater than the length of the interval etching segment.

3. The laser chip according to claim 1, characterized in that: The effective reflectivity of the first grating region is greater than the effective reflectivity of the second grating region.

4. The laser chip according to claim 1, characterized in that: The grating period also includes a non-etched phase-shift segment, and the position of the non-etched phase-shift segment satisfies: Where I0 is the relative intensity of any value; N is the target wavelength λ in the comb reflectance spectrum k The total number of , k is the wavelength subscript; n is the average effective refractive index of the grating area; z is the relative length position of the grating; Λ k represents the required kth target reflection wavelength λ k The corresponding virtual grating period length; θ k is an adjustable phase parameter used to adjust the kth target wavelength λ k The intensity of the corresponding spectral reflection peak; The position of the unetched phase-shift segment is the relative length position z of the grating corresponding to when I(z) is equal to 0.

5. The laser chip according to claim 1, characterized in that: The substrate surface also includes a fourth partition; A phase region is provided between the gain region and the first grating region, and the phase region is used to tune the wavelength of the gain light; The phase zone includes, from bottom to top along the surface of the fourth subzone: a waveguide layer, a spacer layer, and a contact layer; A first hollow region is formed under the waveguide layer of the first grating region, a second hollow region is formed under the waveguide layer of the second grating region, and a third hollow region is formed under the waveguide layer of the phase region; The first hollowed-out area, the second hollowed-out area and the third hollowed-out area are in the same layer, and the first hollowed-out area is connected to the third hollowed-out area.

6. The laser chip according to claim 1, characterized in that: A heating layer is further formed above the contact layer of the first grating region, a protective layer is further formed above the heating layer, a first hollowing region is formed below the waveguide layer of the first grating region, and the first hollowing region allows the heat transferred by the heating layer to be concentrated in the grating layer and the waveguide layer; A heating layer is formed above the contact layer of the second grating region, a protective layer is formed above the heating layer, and a second hollowed-out area is formed below the waveguide layer of the second grating region. The second hollowed-out area concentrates the heat transferred by the heating layer in the grating layer and the waveguide layer.

7. An optical module, characterized in that: The invention is characterized by comprising: Circuit boards; A coherent optical component, electrically connected to the circuit board, for modulation and demodulation of optical signals; A light source is optically connected to the coherent optical component and is used to provide the coherent optical component with light that does not carry data, and includes a laser chip, wherein the laser chip includes any one of the laser chips described in Claims 1 to 6.

8. The optical module according to claim 7, characterized in that: The laser chip comprises a first grating region and a second grating region; the waveguide layer and the grating layer of the first grating region both comprise a first doped region, the first doped region comprises a doping substance, and the first doped region is used to consume free carriers inside the first grating region through the doping substance; The waveguide layer and the grating layer of the second grating region both include a second doped region, wherein the second doped region has a doping substance, and the second doped region is used to consume free carriers inside the second grating region through the doping substance.

9. The optical module according to claim 8, characterized in that: The laser chip further comprises a phase zone, which is used to tune the wavelength; the phase zone comprises a third doping region, wherein the third doping region has a doping substance, and the third doping region is used to consume free carriers inside the phase zone through the doping substance.

10. The optical module according to claim 9, characterized in that: The doping substances in the first doping region, the second doping region, and the third doping region include doped iron.

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