Lateral coupling grating dual-kappa semiconductor laser

Abstract

The invention relates to the technical field of semiconductor lasers, in particular to a lateral coupling grating dual-kappa semiconductor laser. Comprising a substrate, an epitaxial laminated layer and a functional waveguide region formed by etching the epitaxial laminated layer, the functional waveguide region comprises a ridge waveguide and lateral coupling gratings, the ridge waveguide is of a ridge-shaped structure formed by etching in the thickness direction of the epitaxial laminated layer, and the lateral coupling gratings are symmetrically distributed on the two sides of the ridge waveguide; the lateral coupling grating has at least two different geometric parameters along the cavity length direction or the lateral direction of the laser, and the geometric parameters comprise the grating shape, the lateral width, the duty ratio or the offset relative to the side wall of the ridge waveguide; lateral coupling gratings with different geometric parameters generate different coupling strengths for an optical mode field, grating areas with two Kappa values are formed in a laser cavity, and dual-Kappa optical feedback is achieved. The advantages are that the grating structure can be completed through single photoetching and etching; optical feedback of the dual-kappa is realized; cooperative regulation of strong mode selection and low optical loss is realized.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, and more particularly to a side-coupled grating dual-Kappa semiconductor laser. Background Technology

[0002] Semiconductor lasers are the core light source for optical communication and data centers, and their modulation rate and bandwidth directly determine the transmission capacity and reliability of the system. To improve the modulation bandwidth of directly modulated semiconductor lasers, commonly used techniques include optimizing quantum well structures, reducing the volume of the active region, utilizing detuning loading (DL), photon-photon resonance (PPR), and FM-AM conversion effects. The effective implementation of these techniques all relies on precise grating feedback structures.

[0003] Distributed feedback (DFB) and distributed Bragg reflection (DBR) lasers are the mainstream solutions for achieving high-performance single-mode lasing. However, traditional single-coupling coefficient (DBR) lasers... k When dealing with high-speed large-signal modulation, grating structures often suffer from insufficient eye opening and decreased mode stability. To overcome this challenge, the double Kappa grating structure has emerged. Currently, the closest existing technology is disclosed in publication number CN 112600071 A, published on April 2, 2021, entitled "Double Kappa Distributed Bragg Reflector Laser." This scheme adopts a vertical stacked structure, forming two gratings with different etching depths or duty cycles in different sections of the laser cavity, thus creating two different high and low gratings. k The high-speed performance is improved by utilizing the difference in their reflection spectrum characteristics and the synergistic effect of detuning loading. The above-mentioned longitudinal dual-Kappa grating scheme has the following significant drawbacks: (1) High difficulty in process implementation: k The value usually depends on the depth of the grating etching, which requires strict control of the etching process, uniformity and sidewall steepness, making the fabrication difficult and the yield low.

[0004] (2) Significant reliability risks: Different etching depths lead to inconsistent grating heights. During the necessary secondary epitaxy process, lattice defects are easily introduced due to material mismatch, which seriously affects the long-term reliability and lifespan of the device.

[0005] (3) Limited design flexibility: k The control of the value mainly relies on the single dimension of "etching depth", which limits the design freedom and makes it difficult to perform more precise local control of the light field.

[0006] To address the above shortcomings, there is an urgent need to provide a dual-Kappa structure for semiconductor lasers based on a side-coupled grating. Summary of the Invention

[0007] To solve the above problems, the present invention provides a side-coupled grating dual Kappa semiconductor laser.

[0008] The present invention aims to provide a side-coupled grating dual Kappa semiconductor laser, comprising: a substrate, an epitaxial stack, and a functional waveguide region formed by etching the epitaxial stack; The functional waveguide region includes a ridge waveguide and a lateral coupling grating. The ridge waveguide is a ridge-shaped structure etched along the thickness direction of the epitaxial stack, and the lateral coupling gratings are symmetrically distributed on both sides of the ridge waveguide. The lateral coupling grating has at least two different geometric parameters along the length of the laser cavity or in the lateral direction. The geometric parameters include grating shape, lateral width, duty cycle, or offset relative to the ridge waveguide sidewall. Lateral coupling gratings with different geometric parameters produce different coupling intensities to the optical mode field, forming grating regions with two Kappa values ​​in the laser cavity, thus realizing dual Kappa optical feedback.

[0009] Preferably, along the length of the laser cavity, the lateral coupling grating includes a high-calpa value grating region and a low-calpa value grating region; the low-calpa value grating region is symmetrically distributed on both sides of the high-calpa value grating region; the high-calpa value is 3 to 5 times the low-calpa value.

[0010] Preferably, the high-calpa value grating region includes several parallel-arranged wide-tooth gratings, and the low-calpa value grating region includes several parallel-arranged narrow-tooth gratings.

[0011] Preferably, the shape of the lateral coupling grating is rectangular, triangular, trapezoidal, sinusoidal, parabolic, chirped, or a sampling grating structure.

[0012] Preferably, the shape of the lateral coupling grating is rectangular; the tooth width of the rectangular grating in the high kappa value grating region is 1~2 μm, and the tooth width of the rectangular grating in the low kappa value grating region is 0.3~0.8 μm.

[0013] Preferably, the grating in the high-calpa value grating region is in direct contact with the ridge waveguide sidewall and has no offset relative to the ridge waveguide sidewall; the grating in the low-calpa value grating region has a gap with the ridge waveguide sidewall and has an offset of 0.8~2μm relative to the ridge waveguide sidewall.

[0014] Preferably, the lateral coupling grating is fabricated through a single photolithography and etching process; the etching depth of the lateral coupling grating is the same as that of the ridge waveguide.

[0015] Preferably, the coupling coefficient of the lateral coupling grating k Represented as: ; in: k 0 represents the free space wavenumber; n 1 represents the refractive index of the non-grating region;n 2 represents the refractive index of the grating region; Indicates the effective refractive index of the waveguide; m Indicates the order of the grating; Indicates the period of the grating; Indicates the fundamental mode optical field distribution; Z ( y ) represents the grating shape function.

[0016] Compared with the prior art, the present invention can achieve the following beneficial effects: (1) The complexity and difficulty of the process are greatly reduced: All grating structures in this invention can be completed by a single photolithography and a single etching process, and the etching depth is completely consistent. This completely avoids the highly difficult deep etching process.

[0017] (2) It changes from a single dimension of etching depth control to a multi-dimensional design freedom that can simultaneously adjust shape, width, duty cycle, offset, etc., enabling more precise and free design of the light field and k Value distribution. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of rectangular grating teeth of different widths in a laterally coupled grating dual-Kappa semiconductor laser provided according to an embodiment of the present invention.

[0019] Figure 2 These are schematic diagrams of grating teeth of different widths in a laterally coupled grating dual-Kappa semiconductor laser provided according to embodiments of the present invention; (A) triangular; (B) sinusoidal; (C) trapezoidal.

[0020] Figure 3 This is a schematic diagram of rectangular grating teeth with different offsets in a laterally coupled grating dual-Kappa semiconductor laser provided according to an embodiment of the present invention.

[0021] Figure 4 These are schematic diagrams of grating teeth with different offsets in a laterally coupled grating dual-Kappa semiconductor laser provided according to embodiments of the present invention; (A) triangle; (B) sine; (C) trapezoid.

[0022] Figure label: 1. Wide-tooth grating; 2. Narrow-tooth grating; 3. Ridge waveguide; 4. Cap layer; 5. Active region; 6. Substrate; 11. No offset grating; 12. High offset grating; a. Low Kappa value grating region; b. High kappa value grating region. Detailed Implementation

[0023] In the following description, embodiments of the invention will be described with reference to the accompanying drawings. In the description below, the same modules are denoted by the same reference numerals. Where the same reference numerals are used, their names and functions are also the same. Therefore, their detailed description will not be repeated.

[0024] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not constitute a limitation thereof.

[0025] The purpose of this invention is to provide a side-coupled grating dual-Kappa semiconductor laser. This structure abandons the traditional approach of vertical deep etching and instead achieves the spatial distribution of the κ value by designing and fabricating gratings with different geometric shapes or size parameters on the side of the laser ridge waveguide. Its core objective is to significantly reduce fabrication complexity, improve device reliability and yield, and, through the rich design freedom provided by the lateral geometric parameters, better achieve the optical field and feedback control required for high-speed modulation, ultimately obtaining a clearer eye diagram, higher modulation bandwidth, and better mode stability.

[0026] The present invention provides a side-coupled grating dual Kappa semiconductor laser, comprising: a substrate, an epitaxial stack, and a functional waveguide region formed by etching the epitaxial stack; The epitaxial stack is a conventional semiconductor laser epitaxial wafer; The functional waveguide region includes a ridge waveguide and a lateral coupling grating. The ridge waveguide is a ridge-shaped structure formed by etching along the thickness direction of the epitaxial stack. The lateral coupling grating is symmetrically distributed on both sides of the ridge waveguide and is fabricated by a single photolithography and etching process. The lateral coupling grating has at least two different geometric parameters along the length of the laser cavity or in the lateral direction. The geometric parameters include grating shape, lateral width, duty cycle, or offset relative to the ridge waveguide sidewall. Lateral coupling gratings with different geometric parameters produce different coupling intensities to the optical mode field, forming a double Kappa distribution in the laser cavity with a high Kappa value (κ1) grating region and a low Kappa value (κ2) grating region, thus realizing double Kappa optical feedback.

[0027] Preferably, along the length of the laser cavity, the lateral coupling grating includes a high KPa (κ1) grating region and a low KPa (κ2) grating region; the low KPa grating region is symmetrically distributed on both sides of the high KPa grating region; the grating periods of the high KPa grating region and the low KPa grating region are the same; the length of the high KPa grating region accounts for 30% to 50% of the cavity length and is used to provide strong mode selection; the length of the low KPa grating region accounts for 50% to 70% of the cavity length and is used to reduce optical loss. The high kappa value is 3 to 5 times that of the low kappa value; The lateral coupling grating and the ridge waveguide have the same etching depth, which is 1~3μm, and the etching depth does not exceed the thickness of the P-type confinement layer of the epitaxial stack. The shape of the lateral coupling grating can be rectangular, triangular, sinusoidal, or trapezoidal; Specifically, when the shape of the lateral coupling grating is rectangular, the width of the rectangular grating teeth in the high-calpa value grating region is greater than that in the low-calpa value grating region; In some embodiments, the rectangular grating tooth width in the high-calpa value grating region is 1~2μm, and the rectangular grating tooth width in the low-calpa value grating region is 0.3~0.8μm; In some embodiments, the grating period of both the high-calpa value grating region and the low-calpa value grating region is 1~2μm; In some embodiments, the geometric parameters of the high-Kappa grating region satisfy the following: grating lateral width of 1.5~3μm, duty cycle of 0.5~0.7, and no offset relative to the ridge waveguide sidewall; the geometric parameters of the low-Kappa grating region satisfy the following: grating lateral width of 0.5~1μm, duty cycle of 0.2~0.4, and offset relative to the ridge waveguide sidewall of 0.8~2μm. In some embodiments, the ridge waveguide has a width of 2~8μm and a length of 800μm~2mm; the lateral extension width of the single-sided lateral coupling grating is 2~5μm.

[0028] In some embodiments, the epitaxial stack comprises, from bottom to top, an N-type buffer layer, an N-type confinement layer, a lower waveguide layer, an active region, an upper waveguide layer, a P-type confinement layer, and a P-type capping layer; The active region is a multi-quantum-well structure, consisting of 1 to 9 InGaAsP or InAlGaAs quantum wells and GaAsP or InAlGaAs barriers stacked alternately; the materials of the lower waveguide layer and the upper waveguide layer are AlGaAs, InAlGaAs or AlInAs, with a refractive index 0.1 to 2% higher than that of the N-type confinement layer and the P-type confinement layer.

[0029] In some embodiments, the laterally coupled grating dual Kappa semiconductor laser further includes a temperature control component, which includes a heat sink, a heat sink, and a thermistor; the substrate is soldered onto the heat sink, the heat sink is soldered onto the heat sink, and the thermistor is electrically connected to the heat sink for real-time monitoring and regulation of the laser's operating temperature.

[0030] In some embodiments, the front cavity surface of the laser is coated with an antireflection film with a reflectivity of less than 1%; the rear cavity surface is coated with a high reflectivity film with a reflectivity of greater than 99%; the reflectivity of the lateral coupling grating is 10~70%, which is used to form a resonant cavity with the rear cavity surface; the modulation bandwidth of the laser is not less than 20 GHz, the 3dB linewidth is not greater than 0.1 nm, and the side-mode rejection ratio is not less than 10 dB.

[0031] This invention employs a laterally coupled grating structure to achieve different grating KPa values ​​in the laser, based on the grating coupling factor formula: ; in: k Represents the coupling coefficient. k i Indicates refractive index perturbation, indicating k g Gain perturbation; For the laterally coupled grating of this invention, the refractive index coupled grating is mainly considered, therefore the gain coupling coefficient of the imaginary part is ignored; for the laterally coupled grating, its coupling coefficient k It can be represented as: ; in: k 0 represents the free space wavenumber; n 1 represents the refractive index of the non-grating region; n 2 represents the refractive index of the grating region; Indicates the effective refractive index of the waveguide; m Indicates the order of the grating; Indicates the period of the grating; Indicates the fundamental mode optical field distribution; Z ( y The ) represents the grating shape function, which is related to the shape of the grating. Different grating shapes have different functions. For example, the grating shape can be rectangular, triangular, trapezoidal, sine, or parabolic, chirped, or sampling grating structures to meet specific needs.

[0032] This structure can be widely used in electro-absorption modulated lasers (EMLs); it can serve as an active or passive partial double Kappa grating structure on silicon-based photonic integrated circuits; it can also be used to construct double Kappa grating structures in external cavity lasers; furthermore, it is not limited to double Kappa values, but can be designed along the cavity length to design structures with continuously or segmented Kappa values ​​to further optimize performance; by fabricating independent electrodes above different Kappa value regions and injecting different tuning currents, dynamic real-time tuning of lasing wavelength or device performance can be achieved by utilizing thermo-optic or carrier dispersion effects.

[0033] Example 1 See Figure 1 This embodiment provides a laterally coupled grating dual Kappa semiconductor laser based on grating teeth of different widths, including: a substrate 6, an epitaxial stack, and a functional waveguide region formed by etching the epitaxial stack; The epitaxial stack consists of an active region 5 and a cap layer 4 from bottom to top; The functional waveguide region includes a ridge waveguide 3 and a lateral coupling grating. The ridge waveguide 3 is a ridge-shaped structure etched along the thickness direction of the epitaxial stack. The lateral coupling grating is symmetrically distributed on both sides of the ridge waveguide 3 and is fabricated by a single photolithography and etching process. The lateral coupling grating is rectangular in shape. Along the length of the laser cavity, the lateral coupling grating includes a high-calpa value grating region b and a low-calpa value grating region a; the low-calpa value grating region a is symmetrically distributed on both sides of the high-calpa value grating region b; the high-calpa value grating region b includes several parallel wide-tooth gratings 1, and the low-calpa value grating region a includes several parallel narrow-tooth gratings 2. Adjusting by changing the lateral width of the grating strips k Value: such as Figure 1 As shown, the wide-tooth grating 1 can more strongly perturb the light field, thereby achieving high... k The value is lower; while the narrow-tooth grating 2 has a weaker disturbance to the optical field, corresponding to a lower value. k value.

[0034] Example 2 See Figure 2 Figure A shows a laterally coupled grating dual-Kappa semiconductor laser based on grating teeth of different widths. The wide-tooth grating 1 and the narrow-tooth grating 2 are triangular in shape; the rest of the structure is the same as in Embodiment 1.

[0035] Example 3 See Figure 2 Figure B illustrates a laterally coupled grating dual-Kappa semiconductor laser based on gratings of different widths. The wide-tooth grating 1 and the narrow-tooth grating 2 are sinusoidal (half-sine curves). The contours of the sinusoidal gratings undulate periodically along the length of the laser cavity, with the peaks of the half-sine curves pointing laterally outwards towards the laser's edge. The amplitude of the sinusoidal curve in the wide-tooth grating 1 is greater than that in the narrow-tooth grating 2, thus achieving different optical field perturbation intensities. The remaining structure is the same as in Embodiment 1.

[0036] Example 4 See Figure 2 Figure C shows that this embodiment provides a laterally coupled grating dual Kappa semiconductor laser based on grating teeth of different widths. The wide-tooth grating 1 and the narrow-tooth grating 2 are trapezoidal in shape, and the long side of the trapezoid is distributed in accordance with the sidewall of the ridge waveguide 3; the rest of the structure is the same as in embodiment 1.

[0037] Example 5 See Figure 3 This embodiment provides a laterally coupled grating dual Kappa semiconductor laser based on different offsets, including: a substrate 6, an epitaxial stack, and a functional waveguide region formed by etching the epitaxial stack; The epitaxial stack consists of an active region 5 and a cap layer 4 from bottom to top; The functional waveguide region includes a ridge waveguide 3 and a lateral coupling grating. The ridge waveguide 3 is a ridge-shaped structure etched along the thickness direction of the epitaxial stack. The lateral coupling grating is symmetrically distributed on both sides of the ridge waveguide 3 and is fabricated by a single photolithography and etching process. The lateral coupling grating is rectangular in shape. Along the length of the laser cavity, the lateral coupling grating includes a high-calpa value grating region b and a low-calpa value grating region a; the low-calpa value grating region a is symmetrically distributed on both sides of the high-calpa value grating region b; the high-calpa value grating region b includes several parallel-arranged non-offset gratings 11, and the low-calpa value grating region a includes several parallel-arranged high-offset gratings 12. The adjustment is achieved by changing the offset of the grating relative to the sidewall of the ridge waveguide 3. k Value: The offset grating 11 is in direct contact with the sidewall of the ridge waveguide 3, which strongly disturbs the refractive index of the optical field, corresponding to a high value. k Value; the gap between the high-offset grating 12 and the sidewall of the ridge waveguide 3 results in a weaker perturbation to the refractive index of the optical field, corresponding to a low k value.

[0038] Example 6 See Figure 4 Figure A shows a dual Kappa semiconductor laser with a lateral coupling grating based on different offsets, wherein the lateral coupling grating is triangular in shape. In the high-Kappa value grating region b, the unoffset grating 11 is a triangular grating, with its base edge conforming to the sidewall of the ridge waveguide 3; in the low-Kappa value grating region a, the high-offset grating 12 is also a triangular grating, with a gap between its base edge and the sidewall of the ridge waveguide 3; the remaining structures and k The value adjustment logic is the same as in Example 5.

[0039] Example 7 See Figure 4 Figure B shows a dual Kappa semiconductor laser with a lateral coupling grating based on different offsets. The shape of the lateral coupling grating is sinusoidal (half-sine curve). The profile of the unoffset grating 11 in the high KPa value grating region b is a periodic half-sine curve undulating along the length of the laser cavity, with the peak of the half-sine curve facing the lateral outer side of the laser (close to the edge of the laser); the bottom edge of the high-offset grating 12 in the low KPa value grating region a has a gap with the sidewall of the ridge waveguide 3; the amplitude of the sine curve of the unoffset grating 11 is greater than the amplitude of the sine curve of the high-offset grating 12, so as to achieve different optical field perturbation intensities.

[0040] The remaining structure and κ value regulation logic are the same as in Example 5.

[0041] Example 8 See Figure 4Figure C shows a dual Kappa semiconductor laser with a lateral coupling grating based on different offsets, wherein the lateral coupling grating is trapezoidal in shape. The offset grating 11 in the high KPa value grating region b is a trapezoidal grating, with its long side conforming to the sidewall of the ridge waveguide 3; the high offset grating 12 in the low KPa value grating region a is a trapezoidal grating, with a gap between its long side and the sidewall of the ridge waveguide 3; the remaining structures and K value control logic are the same as in Example 5.

[0042] This invention modulates the lateral geometry parameters of the grating precisely. k value: (1) Adjustment by changing the lateral width of the grating strip k Value: As attached Figure 1 As shown, the wide grating teeth 1 (region b) can more strongly perturb the optical field, thereby achieving high... k Value; while the narrow grating teeth 2 (region a) have a weaker disturbance to the optical field, corresponding to a lower value. k value.

[0043] (2) The grating has different shapes: as shown in the attached figure Figure 2 As shown, different shapes such as rectangles, triangles, sines, and trapezoids can be used.

[0044] (3) Fine control can be achieved by changing the duty cycle and lateral offset of the grating: the duty cycle of the grating teeth and slots, as well as the offset of the overall grating structure relative to the ridge waveguide sidewall, can also contribute to achieving precise control. k Value design offers multiple degrees of freedom, as shown in the attached figure. Figure 3 .

[0045] Brief Description of the Invention: This invention innovatively develops a laterally coupled double Kappa grating structure for semiconductor lasers. Based on a conventional semiconductor laser epitaxial wafer, its core technology lies in: fabricating gratings with different geometric features along the cavity length or lateral direction on both sides of the laser ridge waveguide through a single photolithography and etching process; these gratings, due to differences in parameters such as shape (e.g., sinusoidal, triangular, trapezoidal), lateral width, duty cycle, or offset relative to the ridge waveguide sidewall, generate drastically different coupling strengths to the optical mode field, thereby naturally forming the required high ( ) coupling intensity within the laser cavity. k 1) Low ( k 2) Two KPa value distributions are used to achieve the optical feedback function of dual KPa.

[0046] It should be understood that the various forms of processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this invention disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this invention can be achieved, and this is not limited herein.

[0047] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A laterally coupled grating dual kappa semiconductor laser, characterized by: The application relates to a laser device, comprising: a substrate, an epitaxial stack, and a functional waveguide region formed by etching the epitaxial stack; the functional waveguide region comprises a ridge waveguide and a lateral coupling grating, the ridge waveguide is a ridge structure formed by etching along the thickness direction of the epitaxial stack, and the lateral coupling grating is symmetrically distributed on both sides of the ridge waveguide; the lateral coupling grating has at least two different geometric parameters in the laser cavity length direction or in the lateral direction, the geometric parameters include grating shape, lateral width, duty cycle or offset relative to the side wall of the ridge waveguide; the lateral coupling gratings with different geometric parameters have different coupling strengths on the optical mode field, form two grating regions with different kappa values in the laser cavity, and realize double-kappa optical feedback.

2. A laterally coupled grating dual kappa semiconductor laser as claimed in claim 1, characterized in that: In the laser cavity length direction, the lateral coupling grating comprises a high-kappa grating region and a low-kappa grating region; the low-kappa grating region is symmetrically distributed on both sides of the high-kappa grating region; the high-kappa value is 3-5 times the low-kappa value.

3. A laterally coupled grating dual kappa semiconductor laser as claimed in claim 2, wherein: The high-kappa grating region comprises a plurality of parallel arranged wide-tooth gratings, and the low-kappa grating region comprises a plurality of parallel arranged narrow-tooth gratings.

4. A side-coupled grating dual kappa semiconductor laser as claimed in claim 3, wherein: The shape of the lateral coupling grating is rectangular, triangular, trapezoidal, sinusoidal, parabolic, chirped or sampled grating structure.

5. A side-coupled grating dual kappa semiconductor laser as claimed in claim 4, wherein: The shape of the lateral coupling grating is rectangular; the rectangular grating tooth width of the high-kappa grating region is 1-2 mu m, and the rectangular grating tooth width of the low-kappa grating region is 0.3-0.8 mu m.

6. A laterally coupled grating dual kappa semiconductor laser as claimed in claim 2, wherein: The gratings of the high-kappa grating region are in direct contact with the side wall of the ridge waveguide and have no offset relative to the side wall of the ridge waveguide; the gratings of the low-kappa grating region have a gap relative to the side wall of the ridge waveguide, and the offset relative to the side wall of the ridge waveguide is 0.8-2 mu m.

7. A laterally coupled grating dual kappa semiconductor laser as claimed in claim 1, wherein: the first and second semiconductor laser cavities are formed in a single semiconductor chip. The lateral coupling grating is prepared by one-time photolithography and etching process; the etching depth of the lateral coupling grating and the ridge waveguide is the same.

8. A laterally coupled grating dual kappa semiconductor laser as claimed in claim 1, wherein: Coupling coefficient of a lateral coupling grating K is represented as: ； where: k 0 represents the free space wave number; n 1 represents the refractive index of the non-grating region; n 2 represents the refractive index of the grating region; represents the effective refractive index of the waveguide; m represents the order of the grating; represents the period of the grating; represents the fundamental mode optical field distribution; Z ( y ) represents the grating shape function.

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