Laser and manufacturing method therefor

Abstract

A laser (900) and a manufacturing method therefor. The laser (900) comprises a packaging chamber, and a gain chip (910), a wavelength selection assembly and a reflector (960) are separately provided in the packaging chamber. The gain chip (910) comprises a top layer (911), a bottom layer (916) and a light-emitting layer (914). The light-emitting layer (914) comprises a first active region (9141), a passive grating region (9142) and a second active region (9143). The first active region (9141) emits a light beam with a wide wavelength range. The end surface of the passive grating region (9142) can serve as a first resonance end surface of the laser (900). The reflector (960) serves as a second resonance end surface of the laser (900), and forms a resonance chamber with the first resonance end surface. The wavelength selection assembly selects light of a specific wavelength from the light beam with a wide wavelength range; the light of the specific wavelength oscillates back and forth in the resonance chamber to obtain a gain so as to form laser, and the second active region (9143) further performs gain amplification on the laser, thereby improving the output optical power of the laser. On-chip integration of the first active region (9141) and the second active region (9143) is achieved by means of the passive grating region (9142), thereby reducing the volume of the packaging chamber, and miniaturizing the laser.

Description

Laser and preparation method thereof

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 31, 2023, with application number 202311424689.6, the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0002] The present disclosure relates to the field of optical communication technology, and in particular to a laser and a method for manufacturing the same. Background Art

[0003] As demand for communication capacity increases, coherent optical modules are using modulation methods such as Quadrature Amplitude Modulation (QAM) to maximize fiber capacity. However, these modulation methods all have significant insertion loss, requiring tunable lasers to output higher optical power.

[0004] Summary of the Invention

[0005] The present disclosure provides a laser and a method for manufacturing the same.

[0006] According to a first aspect of the present disclosure, a laser is provided, including a packaging cavity, wherein the packaging cavity is provided with:

[0007] Gain chips, including:

[0008] a top layer, comprising a first electrode region and a second electrode region, wherein a first electrical isolation trench is formed between the first electrode region and the second electrode region;

[0009] The bottom layer includes a third electrode region, wherein the third electrode region is electrically connected to the first electrode region and the second electrode region respectively to output carriers;

[0010] The light-emitting layer is located between the top layer and the bottom layer and includes a light-emitting area. The light-emitting area includes the following connected in sequence:

[0011] a first active region located within a downwardly projected region of the first electrode region to receive carriers and configured to emit a light beam having a wide wavelength range based on the injected carriers;

[0012] a passive grating region, located in a downwardly projected region of the first electrical isolation slot, comprising a grating region and a waveguide region, and configured to provide a first resonant end facet for the laser;

[0013] a second active region located within a downwardly projected region of the second electrode region for receiving carriers;

[0014] a wavelength selection component disposed on one side of the first active region and configured to select light of a specific wavelength from the light beam emitted from the first active region;

[0015] a reflector disposed on one side of the wavelength selection component and configured to provide a second resonant end facet for the laser, so that light of a specific wavelength selected by the wavelength selection component oscillates between the first resonant end facet and the second resonant end facet to form laser light, and transmit the laser light to the second active region;

[0016] The second active region is configured to amplify laser light based on the injected carriers.

[0017] According to a second aspect of the present disclosure, a method for preparing a laser is provided, which is applied to the laser provided in the first aspect of the present disclosure, wherein a gain chip is encapsulated in the laser, and the method for preparing the gain chip includes:

[0018] Growing a buffer layer, a multi-quantum well structure layer and a cap layer in sequence from bottom to top;

[0019] Etching longitudinally downward along the local surface of the cap layer to the surface of the buffer layer to form a void area;

[0020] A passive structure is grown on the surface of the empty area, the passive structure including two layers of passive waveguides, and a grating is fabricated on the surface of the upper passive waveguide; a grating cover layer is then grown on the grating surface so that the grating cover layer is flush with the cover layer surface;

[0021] Etching downward along the surface of the cap layer to the surface of the buffer layer to form a first active region, a passive grating region and a second active region respectively;

[0022] After the side surfaces of the first active area, the passive grating area, and the second active area are completed, a sidewall current blocking layer is formed on both sides; an upper confinement layer, a contact layer, and a top layer are sequentially grown along the surface of the first active area, the passive grating area, and the second active area; and at the same time, the growth continues along the bottom surface of the buffer layer until a lower confinement layer is formed;

[0023] Etching downwards along the projection area of ​​the passive grating region on the top layer to form a first electrical isolation groove, wherein a first partition and a second partition are respectively formed on both sides of the first electrical isolation groove;

[0024] Electrode windows are respectively opened on the surfaces of the first subarea and the second subarea, and electrodes are fabricated to form a first electrode region and a second electrode region respectively;

[0025] Electrodes are formed on the bottom surface of the lower confinement layer to form a third electrode region. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solutions of the present disclosure, the following briefly describes the drawings used in some embodiments of the present disclosure. Obviously, the drawings described below are merely illustrations of some embodiments of the present disclosure, and those skilled in the art can also derive other drawings based on these drawings. Furthermore, the drawings described below are schematic diagrams and are not intended to limit the actual dimensions of the products, actual processes of the methods, actual timing of signals, and the like involved in the embodiments of the present disclosure.

[0027] FIG1 is a partial architecture diagram of an optical communication system according to some embodiments of the present disclosure;

[0028] FIG2 is a partial structural diagram of a host computer according to some embodiments of the present disclosure;

[0029] FIG3 is a structural diagram of an optical module provided according to some embodiments of the present disclosure;

[0030] FIG4 is an exploded view of an optical module according to some embodiments of the present disclosure;

[0031] FIG5 is a diagram illustrating the internal structure of an optical module according to some embodiments of the present disclosure;

[0032] FIG6 is a diagram showing the internal structure of a tunable laser according to some embodiments of the present disclosure;

[0033] FIG7 is a structural diagram of a gain chip in a tunable laser according to some embodiments of the present disclosure;

[0034] FIG8 is a cross-sectional view of a gain chip in a tunable laser according to some embodiments of the present disclosure;

[0035] FIG9 is a schematic diagram of optical transmission of a tunable laser in a tunable laser according to some embodiments of the present disclosure;

[0036] FIG10 is a schematic diagram of a process for preparing a gain chip in a tunable laser according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0037] In optical communication technology, to establish information transmission between information processing devices, it is necessary to load the information onto light and use the propagation of light to achieve information transmission. Here, the light loaded with information is an optical signal. When transmitting optical signals within information transmission equipment, they can reduce optical power loss, thereby enabling high-speed, long-distance, and low-cost information transmission. The signals that information processing equipment can recognize and process are electrical signals. Information processing equipment typically includes optical network units (ONUs), gateways, routers, switches, mobile phones, computers, servers, tablets, televisions, etc., and information transmission equipment typically includes optical fibers and optical waveguides.

[0038] Optical modules can convert optical signals into electrical signals between information processing devices and information transmission devices. For example, at least one of the optical signal input or output ends of an optical module is connected to an optical fiber, and at least one of the electrical signal input or output ends of the optical module is connected to an optical network terminal. A first optical signal from the optical fiber is transmitted to the optical module, which converts the first optical signal into a first electrical signal and transmits the first electrical signal to the optical network terminal. A second electrical signal from the optical network terminal is transmitted to the optical module, which converts the second electrical signal into a second optical signal and transmits the second optical signal to the optical fiber. Because multiple information processing devices can transmit information via electrical signals, at least one of the multiple information processing devices needs to be directly connected to the optical module, rather than all of them. Here, the information processing device directly connected to the optical module is referred to as the optical module's host computer. Furthermore, the optical signal input or output end of the optical module can be referred to as an optical port, and the electrical signal input or output end of the optical module can be referred to as an electrical port.

[0039] Figure 1 is a partial architecture diagram of an optical communication system according to some embodiments of the present disclosure. As shown in Figure 1 , 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.

[0040] One end of optical fiber 101 extends toward remote information processing device 1000, and the other end of optical fiber 101 is connected to optical module 200 through the optical port of optical module 200. Optical signals can be totally reflected in optical fiber 101, and the propagation of the optical signal in the direction of total reflection can almost maintain the original optical power. The optical signal undergoes multiple total reflections in optical fiber 101 to transmit the optical signal from remote information processing device 1000 to optical module 200, and vice versa, thereby achieving long-distance, low-power information transmission.

[0041] The optical communication system may include one or more optical fibers 101, and the optical fibers 101 may be 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 operating status of the optical module 200.

[0042] 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 to establish a unidirectional or bidirectional electrical signal connection between the host computer 100 and the optical module 200.

[0043] The host computer 100 also includes an external electrical interface that can access an electrical signal network. For example, the external electrical interface includes a Universal Serial Bus (USB) interface or a network cable interface 104. The network cable interface 104 is configured to access a 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 that an electrical signal connection is established between the local information processing device 2000 and the host computer 100 via the network cable 103. For example, a third electrical signal emitted by the local information processing device 2000 is transmitted to the host computer 100 via the network cable 103. The host computer 100 generates a second electrical signal based on the third electrical signal. The second electrical signal from the host computer 100 is transmitted to the optical module 200. 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. The second optical signal is then transmitted to the remote information processing device 1000 via the optical fiber 101. For example, a first optical signal from the remote information processing device 1000 is transmitted through the optical fiber 101. The first optical signal from the optical fiber 101 is transmitted to the optical module 200. The optical module 200 converts the first optical signal into a first electrical signal. The optical module 200 transmits the first electrical signal to the host computer 100. The host computer 100 generates a fourth electrical signal based on the first electrical signal and transmits the fourth electrical signal to the local information processing device 2000. It should be noted that optical modules are tools for converting optical signals into electrical signals. During this conversion process, the information does not change, but the encoding and decoding methods of the information can change.

[0044] 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.

[0045] Figure 2 is a partial structural diagram of a host computer provided according to some embodiments of the present disclosure. To clearly illustrate the connection between the optical module 200 and the host computer 100, Figure 2 only shows the structure of the host computer 100 related to the optical module 200. As shown in Figure 2, the host computer 100 also includes a PCB circuit board 105 disposed within 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 within the cage 106. The electrical connector is configured to connect to the electrical port of the optical module 200; the heat sink 107 has a raised structure such as fins to increase the heat dissipation area.

[0046] The optical module 200 is inserted into the cage 106 of the host computer 100. The cage 106 secures the optical module 200. Heat generated by the optical module 200 is transferred to the cage 106 and then dissipated through the heat sink 107. After the optical module 200 is inserted into the cage 106, the electrical port of the optical module 200 connects with the electrical connector inside the cage 106, thereby establishing a bidirectional electrical signal connection between the optical module 200 and the host computer 100. Furthermore, the optical port of the optical module 200 connects to the optical fiber 101, thereby establishing a bidirectional optical signal connection between the optical module 200 and the optical fiber 101.

[0047] Figure 3 is a structural diagram of an optical module according to some embodiments of the present disclosure, and Figure 4 is an exploded view of an optical module according to some embodiments of the present disclosure. As shown in Figures 3 and 4, the optical module 200 includes a housing, a circuit board 300 disposed within the housing, a tunable laser 900, and a coherent optical component 1100.

[0048] The housing includes 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.

[0049] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicular to the base 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.

[0050] In some embodiments, the lower shell 202 includes a base plate 2021 and two lower side plates 2022 located on both sides of the base plate 2021 and arranged perpendicularly to the base 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 arranged perpendicularly to the cover plate 2011. The two upper side plates are combined with the two lower side plates 2022 to achieve the upper shell 201 covering the lower shell 202.

[0051] The direction of the line connecting the two openings 204 and 205 can be consistent with the length direction of the optical module 200, or it can be inconsistent with the length direction of the optical module 200. For example, opening 204 is located at the end of the optical module 200 (the right end in Figure 3), and opening 205 is also located at the end of the optical module 200 (the left end in Figure 3). Alternatively, opening 204 is located at the end of the optical module 200, while opening 205 is located on the side of the optical module 200. Opening 204 is an electrical port, and the gold finger 301 of the circuit board 300 extends from opening 204 and is inserted into the electrical connector of the host computer 100. Opening 205 is an optical port, configured to connect to the external optical fiber 101, so that the optical fiber 101 can connect to the tunable laser 900 and coherent optical component 1100 in the optical module 200.

[0052] The combined assembly of the upper housing 201 and the lower housing 202 facilitates installation of the circuit board 300, the tunable laser 900, the coherent optical component 1100, and the like within the housing. The upper housing 201 and the lower housing 202 provide encapsulation and protection for these components. Furthermore, during assembly of the circuit board 300, the tunable laser 900, the coherent optical component 1100, and the like, positioning components, heat dissipation components, and electromagnetic shielding components of these components are easily positioned, facilitating automated production.

[0053] In some embodiments, the upper shell 201 and the lower shell 202 are made of metal materials, which facilitates electromagnetic shielding and heat dissipation.

[0054] 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.

[0055] For example, the unlocking component 600 is located on the outside of the two lower side panels 2022 of the lower housing 202 and includes a snap-fit ​​component that mates with 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 secures 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 between the snap-fit ​​component and the host computer, thereby releasing the optical module 200 from the cage 106 and allowing the optical module 200 to be removed from the cage 106.

[0056] The circuit board 300 includes circuit traces, electronic components, and chips. The electronic components and chips are connected according to the circuit design through the circuit traces to achieve functions such as power supply, electrical signal transmission, and grounding. Electronic components may include, for example, capacitors, resistors, transistors, and metal-oxide-semiconductor field-effect transistors (MOSFETs). Chips may include, for example, microcontroller units (MCUs), laser driver chips, transimpedance amplifiers (TIAs), limiting amplifiers, clock and data recovery chips (CDRs), power management chips, and digital signal processing (DSP) chips.

[0057] 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.

[0058] The circuit board 300 also includes a gold finger 301 formed on its end surface, and 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 set only on the surface of one side of the circuit board 300 (for example, the upper surface shown in Figure 4), or it can be set on the upper and lower surfaces of the circuit board 300 to provide a larger number of pins, thereby adapting to occasions where a large number of pins are required. 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.

[0059] Figure 5 is a diagram showing the internal structure of an optical module according to some embodiments of the present disclosure. As shown in Figure 5 , in some examples of the present disclosure, a tunable laser 900 may be provided on the surface of the circuit board 300 .

[0060] In some examples, a coherent optical component 1100 may be provided on the surface of the circuit board 300. The coherent optical component 1100 may include an optical modulation chip therein. The optical modulation chip is configured to modulate and demodulate an optical signal.

[0061] In some examples, the optical modulation chip can be a silicon photonic chip.

[0062] In some examples, the light modulation chip can be a thin film lithium niobate chip.

[0063] The optical modulation chip lacks its own light source. Instead, the tunable laser 900 serves as an external light source for the optical modulation chip. The tunable laser 900 emits light from the side, which then enters the optical modulation chip, where the built-in modulator modulates the optical signal. The external optical signal enters the optical modulation chip and is coherently demodulated with the local oscillator light, achieving optical signal demodulation.

[0064] Fig. 6 is a diagram illustrating the internal structure of a tunable laser according to some embodiments of the present disclosure. As shown in Fig. 6 , in some embodiments, the tunable laser 900 may include a packaging cavity.

[0065] In some examples, a gain chip 910 may be disposed inside the package cavity.

[0066] In some examples, a lens 920 may be disposed inside the packaging cavity.

[0067] In some examples, a wavelength selection component may be provided inside the package cavity.

[0068] In some examples, the wavelength selection component may include a first filter, such as a first etalon 930 .

[0069] In some examples, the wavelength selection component may include a second filter, such as a second etalon 950 .

[0070] In some examples, a phase shifter 940 may be provided inside the package cavity.

[0071] In some examples, a reflector 960 may be provided inside the packaging cavity.

[0072] In some embodiments, carriers are injected into the gain chip 910, causing it to emit light across a wide wavelength range based on the carriers. Specific currents are then supplied to the first and second etalons 930, 950, respectively, heating them to specific temperatures. This allows light of specific wavelengths to be selected from the broad spectrum, achieving wavelength selection. Wavelength tuning is achieved by supplying different currents to the wavelength selection component to adjust its temperature.

[0073] In some examples, the light emitted by gain chip 910 may be divergent light. Therefore, lens 920 collimates the divergent light beam emitted by gain chip 910 into a parallel light beam, which then enters first etalon 930 as parallel light. The combination of first etalon 930 and second etalon 950 filters out light of wavelengths that can pass through both. In some examples, by heating first etalon 930 and second etalon 950 separately, light of a desired wavelength (target wavelength) can be selected through the vernier effect of both.

[0074] In some examples, the first etalon 930 and the second etalon 950 can be spaced apart to form a vernier etalon. The two etalons have different FSRs (Free spectral ranges). Based on the vernier principle, light waves in the common passable wavelength band of the first etalon 930 and the second etalon 950 can be screened out. That is, when a wavelength in the transmission spectra of the two etalons coincides (i.e., is aligned), light of that specific wavelength can be selected.

[0075] In some embodiments, by heating the first etalon 930 and the second etalon 950 to different temperatures, the refractive indices of the two etalons change accordingly, and the optical path lengths of the two etalons change accordingly. The cavity length of the resonant cavity changes accordingly, and the wavelengths selected by the two etalons change, thereby achieving wavelength tuning.

[0076] In some embodiments, the resonant cavity of the tunable laser 900 is relatively long, and there are many possible oscillating cavity modes. The filter transmission spectrum only allows one of the cavity modes to have low loss and form a laser oscillation output. Because the cavity mode is easily drifted by the influence of temperature, stress, etc., and the output wavelength is related to the cavity mode, which in turn causes the output wavelength to drift, it is necessary to lock the specific wavelength selected by the wavelength selection component. In some embodiments, by changing the temperature of the phase shifter 940 to change the refractive index of the phase shifter 940, the optical length of the phase shifter 940 is changed, and 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, and then lock the wavelength.

[0077] In some embodiments, one end face of the gain chip 910 can be configured as the first resonant end face of the resonant cavity of the tunable laser 900, and the reflector 960 can be configured as the second resonant end face of the resonant cavity, and the first resonant end face and the second resonant end face constitute a resonant cavity. The resonant cavity has a laser mode wavelength (i.e., a resonant wavelength) that it supports. The laser mode can be a longitudinal mode or a transverse mode. The laser mode wavelength is related to the length of the resonant cavity. When the current wavelength is the laser mode wavelength supported by the resonant cavity, the light of the current wavelength can oscillate in the resonant cavity and obtain a positive net gain, ultimately forming a laser output. When the current wavelength is not a wavelength supported by the resonant cavity, the light cannot oscillate in the resonant cavity and eventually disappears in the resonant cavity. By tuning the temperature of the wavelength selection component and tuning the length of the resonant cavity to the resonant cavity length corresponding to light of a specific wavelength (i.e., the target wavelength), the light of the specific wavelength selected by the wavelength selection component reflects back and forth and oscillates in the resonant cavity. When the gain is equal to the loss, spontaneous emission is converted to stimulated emission, thereby forming a laser output.

[0078] In some embodiments of the present disclosure, in order to increase the laser output optical power, a semiconductor optical amplifier may be provided inside the packaging cavity. In some embodiments, a fiber optic adapter may be provided on the outer wall of the packaging cavity, and the fiber optic adapter may be close to the reflector 960. The semiconductor optical amplifier is provided between the fiber optic adapter and the reflector 960, and the oscillated laser is amplified by the semiconductor optical amplifier to increase the laser output optical power. When a semiconductor optical amplifier is used to amplify the optical power, a lens is added between the discrete gain chip and the semiconductor optical amplifier, or the discrete devices are coupled with optical fibers to obtain a higher power output. However, due to problems such as interface reflection and large loss in lens or fiber coupling, the optical power is reduced.

[0079] In some embodiments of the present disclosure, to increase laser output power and avoid the need for separate gain chips and semiconductor optical amplifiers, the gain chip and semiconductor optical amplifier can be integrated. Because one end facet of the gain chip serves as the first resonant end facet, a reflective coating can be applied to that end facet. Since the semiconductor optical amplifier is a one-way optical device, both end faces of the gain chip can be coated with a high-transmittance coating, and the waveguide can be curved and tilted to prevent end facet feedback light from affecting laser mode selection.

[0080] Figure 7 illustrates the structure of a gain chip in a tunable laser according to some embodiments of the present disclosure, and Figure 8 illustrates a cross-sectional view of a gain chip in a tunable laser according to some embodiments of the present disclosure. As shown in Figures 7 and 8 , in some embodiments of the present disclosure, a gain chip 910 may include a top layer 911. This top layer 911 primarily serves as a protective layer, acting as a passivation layer and providing protection against oxidation and water, thereby protecting the gain chip 910. An upper electrode may be formed on the surface of the top layer 911.

[0081] In some examples, the gain chip 910 may include a contact layer 912. The contact layer 912 may be located below the top layer 911. The contact layer 912 may be an ohmic contact layer, and its material may be InGaAs.

[0082] In some examples, the gain chip 910 can include an upper confinement layer 913 . The upper confinement layer 913 can be located below the contact layer 912 .

[0083] In some examples, the gain chip 910 may include a light emitting layer 914 . The light emitting layer 914 may be located below the upper confinement layer 913 .

[0084] In some examples, the gain chip 910 can include a lower confinement layer 915 . The lower confinement layer 915 can be located below the light emitting layer 914 .

[0085] In some examples, the gain chip 910 may include a bottom layer 916. The bottom layer 916 may be located below the lower confinement layer 915. A bottom electrode is formed on the surface of the bottom layer 916. The top and bottom electrodes are respectively connected to the positive and negative electrodes of the power supply, thereby forming an electrical circuit to output carriers.

[0086] In some examples, the upper confinement layer 913 and the lower confinement layer 915 are respectively located on both sides of the light-emitting layer 914 , and are mainly configured to provide a heterojunction to better regulate and limit the carrier recombination area and confine light within the light-emitting layer 914 .

[0087] In some embodiments, the light-emitting layer 914 may include a light-emitting region 914a. The light-emitting region 914a may include a first active region 9141, a passive grating region 9142, and a second active region 9143, which are sequentially connected. For example, the first active region 9141 and the second active region 9143 require power, while the passive grating region 9142 does not. The passive grating region 9142 may include a grating region 9144 and a waveguide region 9145.

[0088] In some embodiments, the first active region 9141 and the second active region 9143 may both adopt a multi-quantum well structure, thereby improving the ability of the active region to collect carriers and increasing the ability of radiative recombination.

[0089] In some embodiments, the passive grating region 9142 can achieve a flat reflection spectrum and act as a reflector, which can serve as the first resonant end face of the laser resonant cavity to reflect light of a specific wavelength. The wavelength range reflected by the passive grating region is affected by the refractive index of the passive grating region, and the fluctuation of the carrier concentration in the region will affect the refractive index. In order to ensure the stability of the effective refractive index of the passive grating region, the injection of carriers into the passive grating region should be avoided. Therefore, in the present disclosure, the surface of the top layer 911 is recessed to form a first electrical isolation groove 917. At this time, the first electrical isolation groove 917 splits the upper electrode into a first electrode region 9111 and a second electrode region 9112, that is, the first electrical isolation groove 917 is located between the first electrode region 9111 and the second electrode region 9112. Furthermore, the first active region 9141 is positioned within the downward projection of the first electrode region 9111, the second active region 9143 is positioned within the downward projection of the second electrode region 9112, and the passive grating region 9142 is positioned within the downward projection of the first electrical isolation trench 917. The provision of the first electrical isolation trench 917 ensures that more carriers are effectively injected into the first active region 9141 and the second active region 9143, thereby maintaining the carrier concentration in the first active region 9141 and the second active region 9143. Furthermore, the provision of the first electrical isolation trench 917 prevents carrier injection into the passive grating region 9142, providing electrical isolation and thereby preventing carrier injection into the passive grating region 9142, thereby ensuring a stable effective refractive index of the passive grating region 9142.

[0090] In some embodiments of the present disclosure, the bottom layer 916 may include a third electrode region, with the third electrode region and the first electrode region 9111 serving as a cathode and an anode, respectively. The first active region 9141 is located below the first electrode region 9111, thereby effectively injecting carriers into the first active region 9141. In some examples, the second active region 9143 is located below the second electrode region 9112, thereby effectively injecting carriers into the second active region 9143.

[0091] In some embodiments, the contact layer 912 has a high electrical conductivity. To prevent carriers from being transmitted through the contact layer 912 into the passive grating region 9142, the first electrical isolation trench 917 is extended downward to the contact layer 912, thereby splitting the contact layer 912 into a first contact region 9121 and a second contact region 9122. For example, the first contact region 9121 may be located below the first electrode region 9111, and the second contact region 9122 may be located below the second electrode region 9112. In some examples, the first electrical isolation trench 917 may continue to extend downward to the upper confinement layer 913.

[0092] In some embodiments, the first active region 9141 may be located directly below the first electrode region 9111, and the second active region 9143 may be located directly below the second electrode region 9112. To prevent carriers from flowing toward both sides of the first active region 9141 and the second active region 9143, thereby reducing the carrier concentration injected into the first active region 9141 and the second active region 9143, a second electrical isolation trench 918 and a third electrical isolation trench 919 may be formed on both sides of the first electrical isolation trench 917. For example, on one side of the first electrical isolation trench 917, a second electrical isolation trench 918 is formed by hollowing out from the top layer 911 downwards. The second electrical isolation trench 918 is located on one side of the light-emitting region 914a. On the other side of the first electrical isolation trench 917, a third electrical isolation trench 919 is formed by hollowing out from the top layer 911 downwards. The third electrical isolation trench 919 is located on the other side of the light-emitting region 914a.

[0093] In some examples, the length of the second electrical isolation groove 918 and the third electrical isolation groove 919 is consistent with the length of the gain chip 910. The length of the second electrical isolation groove 918 and the third electrical isolation groove 919 respectively covers the first active area 9141, the passive grating area 9142 and the second active area 9143 laterally, and the depth of the two can extend downward to the upper confinement layer 913 to fully confine the output carriers to the first active area 9141 and the second active area 9143, avoiding the carriers from being transmitted to both sides of the first active area 9141 and the second active area 9143, and ensuring the carrier concentration transmitted to the first active area 9141 and the second active area 9143.

[0094] In some embodiments, the first active region 9141 can emit spontaneous emission light across a wide wavelength range based on carriers injected from the first electrode region 9111. By tuning the temperature of the wavelength selection component, light of a specific wavelength can be selected from the light beam emitted by the first active region 9141. The selected light of a specific wavelength experiences reduced loss within the resonant cavity formed by the passive grating region 9142 and the reflector 960, reflecting and oscillating back and forth within the resonant cavity. When the gain equals the loss, the spontaneous emission light from the first active region 9141 begins to transition to stimulated emission, forming laser output. The resulting laser light is transmitted through the passive grating region 9142 to the second active region 9143, which amplifies the laser light based on the injected carriers, thereby increasing the laser output power.

[0095] In some embodiments, a fiber adapter 970 may be provided on the outer wall of the package cavity and located near the gain chip 910. Laser light amplified by the second active region 9143 is transmitted into the fiber adapter 970 and then transmitted to the exterior of the tunable laser 900 through the fiber adapter 970, achieving laser emission.

[0096] In some embodiments of the present disclosure, the first electrode region 9111, the first contact region 9121, the upper restriction layer region corresponding to the first contact region 9121, the first active region 9141, the lower restriction layer region corresponding to the first active region 9141 and the corresponding third electrode region are arranged in sequence from top to bottom to constitute a gain region 910a.

[0097] In some examples, the second electrode region 9112, the second contact region 9122, the upper confinement layer region corresponding to the second contact region 9122, the second active region 9143, the lower confinement layer region corresponding to the second active region 9143 and the corresponding third electrode region are arranged in sequence from top to bottom to constitute the optical amplification region 910c.

[0098] The grating region 910b is located between the gain region 910a and the optical amplification region 910c. In some examples of the disclosed embodiments, the optical amplification region 910c is equivalent to an optical amplifier. The optical amplifier is integrated into the gain chip 910, and the gain region 910a is connected to the optical amplification region 910c via the grating region 910b, thereby achieving optical power amplification.

[0099] In some examples of the disclosed embodiments, the grating region 910b can achieve a flat reflection spectrum in the C-band. Therefore, the grating region 910b serves as the first resonant end facet of the resonant cavity, and the reflector 960 serves as the second resonant end facet of the resonant cavity. Light of a selected specific wavelength reflects and oscillates back and forth between the grating region 910b and the reflector 960, and then within the resonant cavity. When the gain equals the loss, the spontaneous emission from the first active region 9141 begins to convert to stimulated emission, forming laser output.

[0100] In some examples of the disclosed embodiments, the gain region 910a and the optical amplification region 910c are electrically isolated by a first electrical isolation trench 917. Therefore, the gain region 910a and the optical amplification region 910c can be electrically tuned independently. For example, different currents can be supplied to the gain region 910a and the optical amplification region 910c, respectively.

[0101] In some embodiments of the present disclosure, a first high-transmittance film 910d and a second high-transmittance film 910e are respectively coated at both ends of the gain chip 910. The first high-transmittance film 910d is disposed adjacent to the first active region 9141, thereby increasing the transmittance of light entering and exiting the first active region 9141. The second high-transmittance film 910e is disposed adjacent to the second active region 9143, thereby increasing the transmittance of light entering and exiting the second active region 9143.

[0102] In some examples of the disclosed embodiments, the presence of grating region 910b enables the integration of an optical amplifier into a gain chip. Grating region 910b connects gain region 910a and optical amplification region 910c. Furthermore, grating region 910b provides a first resonant end facet, allowing light of a specific wavelength to reflect and oscillate back and forth between grating region 910b and reflector 960, resulting in a positive gain layer and, thus, forming a laser. Furthermore, the gain chip 910 is coated with a first high-transmittance film 910d and a second high-transmittance film 910e at both ends, respectively, to ensure the proper operation of the optical amplifier.

[0103] In the laser provided in some embodiments of the present disclosure, the second active region 9143 is integrated into the gain chip 910 through the passive grating region 9142. The second active region 9143 can amplify the laser light formed after oscillation, thereby increasing the output optical power of the laser. In addition, by connecting the first active region 9141 and the second active region 9143 through the passive grating region 9142, problems such as interface reflection can be reduced compared to using a lens or optical fiber, thereby ensuring the output optical power of the laser. In some embodiments of the present disclosure, by integrating the second active region 9143 inside the gain chip 910, the second active region 9143 can be used as an optical amplifier to increase the output optical power of the laser, thereby eliminating the need to separately set up a semiconductor optical amplifier outside the gain chip, thereby reducing the volume of the packaging cavity and facilitating the miniaturization of the laser.

[0104] In some embodiments of the present disclosure, a first active region 9141 and a second active region 9143 are integrated on-chip via a passive grating region 9142. The first active region 9141 functions as a gain region, and the second active region 9143 functions as an optical amplifier to increase the output optical power of the laser. The end facets of the passive grating region 9142 provide an effective reflection end facet for the laser. This eliminates the need for a separate semiconductor optical amplifier external to the gain chip, thereby reducing the volume of the package cavity and facilitating laser miniaturization. Furthermore, this facilitates discrete tuning of the laser's specific characteristics and output optical power to adapt to different operating environments.

[0105] In some embodiments of the present disclosure, the passive grating region 9142 may include a grating region 9144 and a waveguide region 9145. Light of a wide range of wavelengths emitted by the first active region 9141 is transmitted along the waveguide region 9145. In some embodiments, the light spot emitted by the first active region 9141 is relatively large and covers both the grating region 9144 and the waveguide region 9145. For example, the grating region 9144 reflects wavelengths that satisfy the Bragg condition.

[0106] In some embodiments of the present disclosure, the tunable laser is expected to achieve stable power output over a wide wavelength range. If the end face reflectivity difference is large, it will have a greater impact on the threshold, power and SMSR of the laser at different wavelengths, which will increase the difficulty of adjusting the module output power and the power consumption difference. To this end, the grating area 9144 can adopt a passive apodized chirped grating. By transforming the grating structure, a wide-spectrum reflection with uniform reflectivity within the wavelength range can be achieved, thereby achieving stable output of optical power within the band. The grating period of the apodized chirped grating varies gradually with the spatial position, and the feedback intensity varies with the apodization function along the direction of light propagation. The grating intensity variation is controlled by a series of m grating periods as a group, and n high refractive index regions are retained in the m grating periods. The reflectivity of the grating and the reflection spectrum width can be adjusted by adjusting the grating structure and the grating refractive index difference. For example, by adjusting the values ​​of m and n, the grating structure is adjusted, and then the reflectivity and reflection spectrum width of the grating are adjusted to achieve wide-spectrum reflection with uniform reflectivity within the wavelength range, thereby achieving stable output of optical power within the band.

[0107] In some embodiments of the present disclosure, coherent optical communication systems utilize the phase of light to increase communication capacity, requiring tunable laser 900 to have lower phase noise. The transition from 10G to 400G communication systems places higher demands on laser linewidth, relative intensity noise, and other indicators. Accordingly, the linewidth is reduced from 5MHz to 300kHz. For the 16-QAM modulation format, the laser linewidth is required to be less than 100kHz, and the relative intensity noise is required to be reduced to -145dB / Hz.

[0108] In some embodiments, the passive grating region 9142 can be undoped to reduce losses. However, undoped semiconductor materials will still introduce some impurities during the growth process. These impurities will form shallow donor or acceptor energy levels in the band gap. The semiconductor material absorbs photons and generates carriers. The carriers are in a dynamic equilibrium state. The fluctuation of carrier concentration causes changes in the refractive index, which leads to the broadening of the laser spectrum, thereby affecting the line width, relative intensity noise, etc. of the laser.

[0109] In some embodiments, the grating region 9144 and the waveguide region 9145 in the passive grating region 9142 are doped with Fe during the growth process. The doped Fe can serve as a donor energy level to compensate for the shallow donor impurity energy level, thereby reducing the free carrier concentration in the material and forming an insulating layer, thereby reducing the free carrier absorption loss in the material, thereby increasing the light output power of the device and reducing the line width and relative intensity noise of the laser.

[0110] Figure 9 is a schematic diagram of optical transmission within a tunable laser according to some embodiments of the present disclosure. As shown in Figure 9 , in some embodiments of the present disclosure, a fiber adapter 970 is located on one side of an optical amplification region 910c. The following components are arranged in order from one side where the fiber adapter 970 is located to the other side: the fiber adapter 970, the optical amplification region 910c, the grating region 910b, the gain region 910a, a wavelength selection component, and a reflector 960. For example, the wavelength selection component may include a first etalon 930 and a second etalon 950.

[0111] The grating region 910b can serve as the first resonant end facet of the resonant cavity, and the reflector 960 can serve as the second resonant end facet of the resonant cavity. The gain region 910a emits a beam of light across a wide range of wavelengths based on the injected carriers. By tuning the temperature of the wavelength selection component, light of a specific wavelength is selected from the wide range of wavelengths. This specific wavelength, the target wavelength, reflects and oscillates within the resonant cavity, achieving positive gain and thus forming a laser. The oscillated laser light is transmitted through the grating region 910b to the fiber adapter 970, and then through the fiber adapter 970 to the exterior of the tunable laser 900, providing a light source for the coherent optical component.

[0112] In some embodiments, a second high-transmittance film 910e may be coated on the side of the optical amplification region 910c facing the optical fiber adapter 970, and a first high-transmittance film 910d may be coated on the side of the gain region 910a facing the first etalon 930. The first high-transmittance film 910d is disposed adjacent to the first active region 9141 in the gain region 910a, thereby increasing the transmittance of light entering and exiting the first active region 9141. The second high-transmittance film 910e is disposed adjacent to the second active region 9143 in the optical amplification region 910c, thereby increasing the transmittance of light entering and exiting the second active region 9143.

[0113] In some embodiments of the present disclosure, the two sides of the grating region 910b can be connected to the gain region 910a and the optical amplifier region 910c respectively using a docking growth process, thereby integrating the optical amplifier into the gain chip, in order to obtain a gain chip that can output higher optical power.

[0114] In the laser provided by some embodiments of the present disclosure, the laser includes a packaging cavity, and a gain chip, a wavelength selection component and a reflector are respectively provided inside the packaging cavity. The gain chip includes a top layer, a bottom layer and a light-emitting layer located between the top layer and the bottom layer, the light-emitting layer includes a light-emitting area, and the light-emitting area includes a first active area, a passive grating area and a second active area connected in sequence. The top layer includes a first electrode area and a second electrode area, and a first electrical isolation groove is formed between the first electrode area and the second electrode area; the bottom layer includes a third electrode area, and the third electrode area is electrically connected to the first electrode area and the second electrode area, respectively, to inject carriers into the first active area and the second active area, respectively. The first active area is located in the downward projection area of ​​the first electrode area, and emits a light beam with a wide wavelength range according to the injected carriers. The passive grating area includes a grating, which acts as a reflector and can serve as the first resonant end face of the laser resonant cavity to reflect light of a specific wavelength. The wavelength reflected by the passive grating region is related to its effective refractive index, which in turn is related to the magnitude of the current. To ensure the stability of the effective refractive index of the passive grating region, carrier injection into the passive grating region should be avoided. Therefore, the present disclosure positions the passive grating region within the downward projection of the first electrical isolation groove. The placement of the first electrical isolation groove prevents carriers from flowing into the passive grating region, providing electrical isolation and thus preventing carrier injection into the passive grating region. The second active region is positioned within the downward projection of the second electrode region. In the present disclosure, the reflector serves as the second resonant end facet of the laser resonant cavity, with the first and second resonant end faces forming the laser resonant cavity. In the present disclosure, a wavelength selection component selects light of a specific wavelength from the broad wavelength range of the light beam output by the first active region. This specific wavelength of light reflects back and forth within the resonant cavity, oscillating and generating positive gain to form a laser beam. The generated laser beam is then transmitted along the passive grating region to the second active region, where it amplifies the laser beam gain based on the injected carriers, thereby increasing the output optical power of the laser beam. In the laser provided by the present disclosure, the second active region is integrated into the gain chip through the passive grating region. The second active region can amplify the laser formed after oscillation, thereby increasing the output optical power of the laser. In addition, the first active region and the second active region are connected through the passive grating region, which can reduce problems such as interface reflection compared to using a lens or optical fiber, thereby ensuring the output optical power of the laser. The present disclosure realizes on-chip integration of the first active region and the second active region through the passive grating region. The first active region serves as a gain region, and the second active region serves as an optical amplifier to increase the output optical power of the laser. The end face of the passive grating region provides an effective reflection end face for the laser, thereby eliminating the need to separately set a semiconductor optical amplifier outside the gain chip, thereby reducing the volume of the packaging cavity and facilitating the miniaturization of the laser. In addition, it is also beneficial for the discrete tuning of the laser specificity and output optical power to adapt to different usage environments.

[0115] Some embodiments of the present disclosure provide a method for preparing a laser, which is applied to the above-mentioned laser. A gain chip is packaged in the laser, so the method for preparing the laser includes a method for preparing the gain chip.

[0116] FIG10 is a schematic diagram of a process for preparing a gain chip in a tunable laser according to some embodiments of the present disclosure. As shown in FIG10 , in some embodiments of the present disclosure, the process for preparing the gain chip 110 includes:

[0117] S110: growing a buffer layer c, a multi-quantum well structure layer b and a cap layer a in sequence from bottom to top.

[0118] In some embodiments, the multi-quantum well structure layer b is encapsulated between the buffer layer c and the cap layer a. The multi-quantum well structure layer b is used for the subsequent preparation of the first active region 9141 and the second active region 9143. Both the first active region 9141 and the second active region 9143 utilize a multi-quantum well structure, thereby improving the active region's ability to collect carriers and increasing the ability for radiative recombination. As the number of quantum wells increases, the amount of activated material increases, and the optical gain gradually increases, thereby increasing the output optical power.

[0119] S120: Etching longitudinally downward along the local surface of the cap layer to the surface of the buffer layer to form an empty area A.

[0120] In some embodiments, one side of the empty region A corresponds to the optical amplification region 910c, the other side of the empty region A corresponds to the gain region 910a, and the empty region A corresponds to the grating region 910b. Exemplarily, the empty region A is excavated for the subsequent growth of the passive grating region 9142.

[0121] S130: A passive structure is grown on the surface of the empty area A, where the passive structure includes two layers of passive waveguides. A grating area 9144 is made on the surface of the upper passive waveguide. A grating covering layer is then grown on the surface of the grating area 9144 to make the grating covering layer flush with the surface of the cover layer a.

[0122] In some embodiments, a passive structure is grown on the surface of the empty area A. The passive structure includes two layers of InGaAsP passive waveguide structures, and the top, bottom, and middle of the material are filled with InP material.

[0123] In some embodiments, the grating region 9144 uses a passive apodized chirped grating. By transforming the grating structure, wide-spectrum reflection with uniform reflectivity within the wavelength range can be achieved, thereby achieving stable output of optical power.

[0124] S140: Etching along the surface of the cap layer downwards to the surface of the buffer layer to form a first active region, a passive grating region and a second active region.

[0125] In some embodiments, etching is performed along the surface of the cap layer down to the surface of the buffer layer, retaining the light-emitting region 914 a , thereby forming a first active region 9141 , a passive grating region 9142 , and a second active region 9143 .

[0126] S150: After the side surfaces of the first active area, the passive grating area and the second active area are completed, a sidewall current blocking layer is grown on both sides; an upper confinement layer, a contact layer and a top layer are grown upward along the surfaces of the first active area, the passive grating area and the second active area until an upper confinement layer, a contact layer and a top layer are formed in sequence; and the growth continues along the bottom surface of the buffer layer until a lower confinement layer is formed.

[0127] In some embodiments, after the side surfaces of the first active region 9141 , the passive grating region 9142 , and the second active region 9143 are completed, sidewall current blocking layers are grown on both sides.

[0128] It grows upward along the surfaces of the first active region 9141 , the passive grating region 9142 and the second active region 9143 until an upper confinement layer, a contact layer and a top layer are formed in sequence; and continues to grow along the bottom surface of the buffer layer until a lower confinement layer is formed.

[0129] S160: Etching downwards along the projection area of ​​the passive grating region on the top layer to form a first electrical isolation groove, wherein a first partition and a second partition are respectively formed on both sides of the first electrical isolation groove.

[0130] In some embodiments, etching is performed downward along the projection of the passive grating region on the top layer to form a first electrical isolation trench 917. Furthermore, a second electrical isolation trench 918 and a third electrical isolation trench 919 are formed on either side of the first electrical isolation trench 917. For example, on one side of the first electrical isolation trench 917, the top layer 911 is hollowed out downward to form the second electrical isolation trench 918, which is located on one side of the light-emitting region 914a. On the other side of the first electrical isolation trench 917, the top layer 911 is hollowed out downward to form the third electrical isolation trench 919, which is located on the other side of the light-emitting region 914a.

[0131] S170: growing a protection layer on the current top surface to form a top layer.

[0132] In some embodiments, a protective layer is grown on the top surface of the current chip. The protective layer is a passivation layer that plays a role in preventing oxidation and waterproofing, thereby protecting the gain chip 910 .

[0133] S180: Electrode windows are respectively opened on the surfaces of the first subarea and the second subarea.

[0134] In some embodiments, electrode windows B and electrode windows C are respectively opened on the surfaces of the first partition and the second partition.

[0135] S190: Fabricating electrodes on the surface of the electrode window to form a first electrode region and a second electrode region respectively.

[0136] In some embodiments, electrodes are fabricated on the surfaces of electrode window B and electrode window C to form a first electrode region 9111 and a second electrode region 9112 , respectively.

[0137] S200: Bottom table at the lower limit layer

[0138] Electrodes are fabricated on the surface to form a third electrode area.

[0139] In some embodiments, the bottom surface of the lower confinement layer 915 is thinned and an electrode is fabricated to form a third electrode region located at the bottom layer of the laser.

[0140] The third electrode region is electrically connected to the first electrode region 9111, and the first active region 9141 is located below the first electrode region 9111, thereby effectively injecting carriers into the first active region 9141. Similarly, the third electrode region is electrically connected to the second electrode region 9112, and the second active region 9143 is located below the second electrode region 9112, thereby effectively injecting carriers into the second active region 9143.

[0141] In some embodiments of the present disclosure, a first high-transmittance film 910d and a second high-transmittance film 910e are respectively coated at both ends of the gain chip 910. The first high-transmittance film 910d is disposed adjacent to the first active region 9141, thereby increasing the transmittance of light entering and exiting the first active region 9141. The second high-transmittance film 910e is disposed adjacent to the second active region 9143, thereby increasing the transmittance of light entering and exiting the second active region 9143.

[0142] In the tunable laser disclosed herein, the grating region is located between the gain region and the optical amplifier region. The optical amplifier region is equivalent to an optical amplifier. The optical amplifier is integrated into the gain chip and connected to the gain region and the optical amplifier region via the grating region, thereby achieving optical power amplification and achieving higher optical power output.

[0143] In the present disclosure, the grating region can achieve a flat reflection spectrum over a wide wavelength range. Therefore, the grating region serves as the first resonant end face of the resonant cavity, and the reflector serves as the second resonant end face of the resonant cavity. Light of a specific wavelength is selected and reflected back and forth between the grating region and the reflector, oscillating. When the gain is greater than the loss, the spontaneous emission from the first active region is converted to stimulated emission, forming laser output. The resulting laser light is transmitted through the passive grating region to the second active region, which amplifies the laser light based on the injected carriers, thereby increasing the laser output power.

[0144] In the present disclosure, the gain region and the optical amplification region are electrically isolated by a first electrical isolation trench, so the gain region and the optical amplification region can be tuned independently. For example, different currents can be provided to the gain region and the optical amplification region respectively.

[0145] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that a person skilled in the art can conceive within the technical scope disclosed in the present disclosure should be included within the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A laser, comprising a packaging cavity, wherein the packaging cavity is provided with: Gain chips, including: A top layer, comprising a first electrode region and a second electrode region, wherein a first electrical isolation groove is formed between the first electrode region and the second electrode region; A bottom layer, comprising a third electrode region, wherein the third electrode region is electrically connected to the first electrode region and the second electrode region respectively to output carriers; The light-emitting layer is located between the top layer and the bottom layer, and includes a light-emitting area, wherein the light-emitting area includes: a first active region, located within a downwardly projected region of the first electrode region to receive the carriers, and configured to emit a light beam in a wide wavelength range according to the injected carriers; a passive grating region, located in a downwardly projected region of the first electrical isolation slot, comprising a grating region and a waveguide region, and configured to provide a first resonant end face for the laser; a second active region, located within a downwardly projected region of the second electrode region, to receive the carriers; a wavelength selection component, disposed at one side of the first active region, configured to select light of a specific wavelength from the light beam emitted from the first active region; a reflector, disposed at one side of the wavelength selection component, configured to provide a second resonant end facet for the laser, so that the light of a specific wavelength selected by the wavelength selection component oscillates between the first resonant end facet and the second resonant end facet to form laser light, and transmits the laser light to the second active region; The second active region is configured to amplify the laser light according to the injected carriers.

2. The laser according to claim 1, wherein: A contact layer and an upper limiting layer are formed between the top layer and the light-emitting layer from top to bottom; A lower limiting layer is formed between the light-emitting layer and the bottom layer; The first electrical isolation groove extends downward to the contact layer, so that the contact layer is divided into a first contact region and a second contact region, wherein the first contact region is located below the first electrode region and the second contact region is located below the second electrode region.

3. The laser according to claim 1, wherein: On one side of the first electrical isolation groove, a second electrical isolation groove is formed by hollowing out from the top layer downwards, and the second electrical isolation groove is located on one side of the light emitting area; On the other side of the first electrical isolation groove, a third electrical isolation groove is hollowed out downward from the top layer to form the third electrical isolation groove, and the third electrical isolation groove is located on the other side of the light emitting area.

4. The laser according to claim 1, wherein The grating region includes an apodized chirped grating.

5. The laser according to claim 1, wherein The two side end surfaces of the gain chip are respectively plated with a first anti-reflection film and a second anti-reflection film.

6. The laser according to claim 1, wherein An optical fiber adapter is provided on the outer wall of the packaging cavity, and the optical fiber adapter is located at one side of the second active area; The light amplified by the second active region is output through the optical fiber adapter.

7. The laser according to claim 6, wherein: The optical fiber adapter, the gain chip, the wavelength selection component and the reflector are respectively arranged along one side to the other side of the packaging cavity; The second active region is closer to the optical fiber adapter than to the grating region.

8. A method for preparing a laser, applied to the laser according to any one of claims 1 to 7, wherein a gain chip is encapsulated in the laser, and the method for preparing the gain chip comprises: Growing a buffer layer, a multi-quantum well structure layer and a cap layer in sequence from bottom to top; Etching longitudinally downward along the local surface of the cap layer to the surface of the buffer layer to form a void area; A passive structure is grown on the surface of the empty area, wherein the passive structure includes two layers of passive waveguides, and a grating is made on the surface of the passive waveguide on the upper layer; then a grating cover layer is grown on the surface of the grating so that the grating cover layer is flush with the surface of the cover layer; Etching along the surface of the cap layer downward to the surface of the buffer layer to form a first active region, a passive grating region and a second active region respectively; After the side surfaces of the first active area, the passive grating area and the second active area are completed, a sidewall current blocking layer is formed on both sides; an upper limiting layer, a contact layer and a top layer are grown upward along the surfaces of the first active area, the passive grating area and the second active area until an upper limiting layer, a contact layer and a top layer are formed in sequence; and at the same time, the bottom surface of the buffer layer is continued to grow until a lower limiting layer is formed; Etching downwards along the projection area of ​​the passive grating region on the top layer to form a first electrical isolation groove, wherein a first partition and a second partition are respectively formed on both sides of the first electrical isolation groove; Opening electrode windows on the surfaces of the first subarea and the second subarea respectively, and performing electrode manufacturing to form a first electrode area and a second electrode area respectively; Electrode manufacturing is performed on the bottom surface of the lower confinement layer to form a third electrode region.

9. The method for preparing a laser according to claim 8, wherein: While forming the first electrical isolation groove, on one side of the first electrical isolation groove, hollowing out from the top layer downwards to form a second electrical isolation groove, wherein the second electrical isolation groove is located on one side of the light-emitting layer; On the other side of the first electrical isolation groove, a third electrical isolation groove is formed by hollowing out from the top layer downwards. The third electrical isolation groove is located on the other side of the light-emitting layer.

10. The method for preparing a laser according to claim 8, wherein: After the third electrode region is formed, a first anti-reflection film and a second anti-reflection film are respectively plated on both side end surfaces of the gain chip.

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