Semiconductor laser device

Abstract

The invention relates to the technical field of semiconductor devices, in particular to a semiconductor laser device, which comprises a substrate; the ridge waveguide array comprises a fundamental mode waveguide array and a coupling waveguide array, the fundamental mode waveguide array comprises N fundamental mode waveguides, the coupling waveguide array comprises a plurality of coupling waveguides, and at least one coupling waveguide is provided with an optical loss structure; an electrical isolation structure; the coupling waveguide array is located on one side of the fundamental mode waveguide array, and the number of the coupling waveguides is N-1; or, the two coupling waveguide arrays are located on the two opposite sides of the fundamental mode waveguide array respectively, and the number of the coupling waveguides in each coupling waveguide array is N-1; or, the two coupling waveguide arrays are located on the two opposite sides of the fundamental mode waveguide array respectively, and the total number of the coupling waveguides of the two coupling waveguide arrays is N-1. The semiconductor laser device is at least beneficial to realizing high-power output of the fundamental mode of the semiconductor laser device.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor devices, and in particular relates to a semiconductor laser device. Background Art

[0002] Semiconductor lasers and semiconductor laser amplifiers operating in high-power fundamental mode have been widely used in fiber-optic communications, sensing, lidar and other fields due to their excellent beam quality and pure spectral characteristics. Since light will inevitably encounter various losses when transmitting in the medium, the demand for fundamental mode output power in practical applications is getting higher and higher. In order to obtain fundamental mode output, semiconductor laser chips generally use a narrow ridge structure, and the width of the narrow ridge structure is usually in the range of 2μm~4μm. If the output power is to be increased, the general means is to increase the area of ​​the gain region of the injected current, that is, to increase the width of the narrow ridge structure. However, due to theoretical limitations, it is difficult to maintain the fundamental mode output while further increasing the width of the narrow ridge structure. Therefore, when maintaining the fundamental mode operation, the area of ​​the gain region of the injected current is very small, resulting in a low overall gain of the laser device, making the final fundamental mode output power very limited. Summary of the invention

[0003] In view of this, the present invention aims to provide a semiconductor laser device, which is at least conducive to achieving high power output of the fundamental mode of the semiconductor laser device.

[0004] To achieve the above object, the technical solution created by the present invention is implemented as follows: The invention provides a semiconductor laser device, comprising: a substrate; a working layer, the working layer is located on the surface of the substrate, a ridge waveguide array is provided on a side of the working layer away from the substrate, the ridge waveguide array comprises a fundamental mode waveguide array and a coupling waveguide array, the fundamental mode waveguide array comprises N fundamental mode waveguides arranged at intervals along a first direction, the coupling waveguide array comprises a plurality of coupling waveguides arranged at intervals along the first direction, the coupling waveguide array is located on at least one side of the fundamental mode waveguide array in the first direction, at least one coupling waveguide has an optical loss structure; an electrical isolation structure, the electrical isolation structure The structure is used to achieve electrical isolation between the fundamental mode waveguide array and the coupled waveguide array; wherein the coupled waveguide array is located on one side of the fundamental mode waveguide array, the number of coupled waveguides is N-1, and N is an integer greater than 2; or, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array, the number of coupled waveguides in each coupled waveguide array is N-1, and N is an integer greater than 2; or, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array, the total number of coupled waveguides of the two coupled waveguide arrays is N-1, and N is an integer greater than 3.

[0005] Furthermore, the coupled waveguide array is located at one side of the fundamental mode waveguide array in the first direction, and each coupled waveguide in the coupled waveguide array has an optical loss structure.

[0006] Furthermore, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array in the first direction, the total number of coupled waveguides in the two coupled waveguide arrays is N-1, N is an odd number, and the number of coupled waveguides in the two coupled waveguide arrays is the same.

[0007] Further, along the extension direction of the fundamental mode waveguide, the width of the fundamental mode waveguide in the first direction gradually increases, and along the extension direction of the coupled waveguide, the width of the coupled waveguide in the first direction gradually increases.

[0008] Furthermore, the fundamental mode waveguide has a first end, a first middle part and a second end arranged along the extension direction, the size of the fundamental mode waveguide in the first direction gradually decreases from the first end to the middle part, and the size of the fundamental mode waveguide in the first direction gradually decreases from the second end to the middle part; the coupled waveguide has a third end, a second middle part and a fourth end arranged along the extension direction, the size of the coupled waveguide in the first direction gradually decreases from the third end to the second middle part, and the size of the coupled waveguide in the first direction gradually decreases from the fourth end to the second middle part.

[0009] Further, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array in the first direction, and each coupled waveguide in each coupled waveguide array has an optical loss structure.

[0010] Furthermore, the optical loss structures in the two coupled waveguide arrays located on opposite sides of the fundamental mode waveguide array are arranged differently.

[0011] Furthermore, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array in the first direction, and in each coupled waveguide array, except for one coupled waveguide adjacent to the fundamental mode waveguide array, the remaining coupled waveguides have an optical loss structure.

[0012] Furthermore, the optical loss structure extends from the coupling waveguide away from the top surface of the substrate toward the substrate.

[0013] Furthermore, the optical loss structure is disposed in the working layer below the coupling waveguide, and a plurality of optical loss structures are arranged at intervals along the thickness direction of the working layer, and each optical loss structure extends along the first direction.

[0014] Compared with the prior art, the invention can at least achieve the following beneficial effects: the technical advantage of the embodiment of the present invention is that the flow direction of the current is limited by the electrical isolation structure, so that the injected current mainly passes through the fundamental mode waveguide, which improves the current utilization rate, thereby helping to reduce the threshold current of the fundamental mode operation of the semiconductor laser device, and is conducive to improving the photoelectric conversion efficiency of the fundamental mode operation of the semiconductor laser device; by setting the optical loss structure, the loss of the high-order mode is improved, the threshold current of the high-order mode is further improved, and the working current range of the semiconductor laser device in the fundamental mode operation is expanded, and even the fundamental mode operation can be achieved before the semiconductor laser device is thermally reversed, so that a high-power semiconductor laser device working in the fundamental mode can be obtained. In addition, the semiconductor laser device provided by the embodiment of the present invention can achieve the output of fundamental mode laser with narrow divergence angle, high brightness, high beam quality and pure spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A schematic structural diagram of a first embodiment of a semiconductor laser device according to an embodiment of the present invention; Figure 2 A schematic structural diagram of a second embodiment of the semiconductor laser device according to an embodiment of the present invention; Figure 3 A schematic structural diagram of a third embodiment of a semiconductor laser device according to an embodiment of the present invention; Figure 4 A schematic structural diagram of a fourth embodiment of a semiconductor laser device according to an embodiment of the present invention; Figure 5 The present invention is a schematic structural diagram of a fifth embodiment of the semiconductor laser device described in the present invention.

[0016] Explanation of the reference numerals: 1, substrate; 2, working layer; 11, fundamental mode waveguide array; 12, coupled waveguide array; 21, electrical isolation structure; 31, optical loss structure; X, first direction. DETAILED DESCRIPTION

[0017] After analysis, it was found that in order to solve the problem of increasing the gain area of ​​the injected current while maintaining the fundamental mode operation, the main waveguide and the coupled waveguide can be constructed, and the coupled waveguide can be used to couple the high-order mode, thereby increasing the threshold of the high-order mode and realizing the fundamental mode lasing. However, it still has the following disadvantages: The coupling waveguide is not electrically isolated from the main waveguide. The lack of electrical isolation means that when current is injected, the injected current diffuses laterally farther, which leads to two obvious disadvantages: on the one hand, as the current injection diffuses laterally, the coupling waveguide is still in a state where current passes through it, and the quantum well in the device is pumped by current, resulting in gain in the coupling waveguide. As a result, the device can only maintain fundamental mode lasing under optical pumping or low current injection, and still exhibits multi-mode lasing under high current injection, which degrades the beam quality and affects the far-field spot brightness of the laser. On the other hand, the lateral diffusion of current injection will cause the coupling waveguide to work in the fundamental mode without the generation and amplification of photons, but there is still current. This part of the injected current is not converted into light, but is all converted into heat, thereby increasing the fundamental mode threshold current of the device and reducing the photoelectric conversion efficiency of the device. No optical loss structure is introduced. No optical loss means that under high-power working conditions with large current injection, high-order modes can easily overcome the very small waveguide loss in the coupled wave, resulting in a smaller current range for fundamental mode operation and a lower maximum power for fundamental mode operation, which leads to multi-mode lasing in the device, deteriorating the beam quality and divergence angle, reducing the brightness, and widening the spectral width range.

[0018] To solve the above problems, an embodiment of the present invention provides a semiconductor laser device, which is helpful in solving the problem of increased fundamental mode operating threshold current caused by lateral diffusion of current, and is helpful in solving the problem of high-order mode lasing under high current injection conditions, and is helpful in reducing the fundamental mode operating threshold current, improving efficiency, expanding the current and power range of fundamental mode operation, obtaining high-power fundamental mode lasing, and improving beam quality and brightness.

[0019] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0021] In the description of the invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the invention, unless otherwise specified, the meaning of "multiple" is two or more.

[0022] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0023] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0024] refer to Figures 1 to 5The present invention provides a semiconductor laser device, comprising: a substrate 1; a working layer 2, the working layer 2 is located on the surface of the substrate 1, and the side of the working layer 2 away from the substrate 1 has a ridge waveguide array, the ridge waveguide array includes a fundamental mode waveguide array 11 and a coupling waveguide array 12, the fundamental mode waveguide array 11 includes N fundamental mode waveguides arranged at intervals along a first direction X, the coupling waveguide array 12 includes a plurality of coupling waveguides arranged at intervals along the first direction X, the coupling waveguide array 12 is located on at least one side of the fundamental mode waveguide array 11 in the first direction X, and at least one coupling waveguide has an optical loss structure 31; an electrical isolation structure 21, the electrical isolation The isolation structure 21 is used to achieve electrical isolation between the fundamental mode waveguide array 11 and the coupled waveguide array 12; wherein the coupled waveguide array 12 is located on one side of the fundamental mode waveguide array 11, and the number of coupled waveguides is N-1, where N is an integer greater than 2; or, the two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the number of coupled waveguides in each coupled waveguide array 12 is N-1, where N is an integer greater than 2; or, the two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the total number of coupled waveguides of the two coupled waveguide arrays 12 is N-1, where N is an integer greater than 3.

[0025] In some embodiments of the present invention, the semiconductor laser device provided by the embodiments of the present invention can be a semiconductor laser that operates in a high-power fundamental mode, which is conducive to obtaining high-power, high-beam quality and high-brightness fundamental mode laser output.

[0026] In some embodiments of the present invention, on the basis of the semiconductor laser device provided by the embodiment of the present invention, other optical structures may be further introduced, such as a grating structure or a tapered amplification structure, etc., which is conducive to promoting the development of high-power distributed Bragg reflection lasers, distributed feedback lasers and other devices. In other embodiments of the present invention, the semiconductor laser device provided by the embodiment of the present invention may also be a tapered laser, a semiconductor optical amplifier, a reflective semiconductor optical amplifier and other devices.

[0027] In the semiconductor laser device provided by the embodiment of the present invention, the substrate 1 is the preparation basis of the entire semiconductor laser device, and other structures of the semiconductor laser device are prepared on the substrate 1. The working layer 2 is the semiconductor laser working layer, and the working layer 2 is the main component of the semiconductor laser device. In some examples, the working layer 2 may include: a buffer layer, an upper cladding layer, a lower cladding layer, a waveguide layer, a layer for limiting heterojunctions, an active layer, and a cap layer. The working layer 2 is used to generate optical gain based on the optical waveguide effect under current injection, and the ridge waveguide array is usually formed by the ridge structure of the waveguide layer.

[0028] The fundamental mode waveguide array 11 is the main optical field energy distribution area of ​​the fundamental mode. When the semiconductor laser device is working, it is energized to generate optical gain. The fundamental mode waveguide array 11 provided in the embodiment of the present invention includes multiple fundamental mode waveguides, which is beneficial to increase the area of ​​the gain region of the injected current. It should be noted that the width of each fundamental mode waveguide in the fundamental mode waveguide array 11 can be the same or different, and the spacing distance between two adjacent fundamental mode waveguides can be the same or different.

[0029] The coupling waveguide array 12 is distributed on one side or both sides of the fundamental mode waveguide array 11, and the coupling waveguide array 12 is configured to have the same or similar propagation constant as the high-order mode of the fundamental mode waveguide, so as to couple the high-order mode into the coupling waveguide. It should be noted that the physical definition of the transmission constant is 2×π / (laser wavelength / effective refractive index). When the difference in the effective refractive index between the two is less than 0.005, the embodiment of the present invention considers that the propagation constants of the two are similar. For the coupling waveguide array 12 distributed on both sides of the fundamental mode waveguide, the propagation constant of the optical mode of the coupling waveguide array 12 on one side can be set to be equal to or approximately equal to the propagation constant of one or several high-order modes in the fundamental mode waveguide. The propagation constant of the optical mode of the coupling waveguide array 12 is approximately equal to the propagation constant of one or several high-order modes in the fundamental mode waveguide, which means that the propagation constants of the two are similar. The propagation constant of the optical mode of the coupling waveguide array 12 on the other side is equal to or approximately equal to (the propagation constants are similar) the propagation constant of the high-order modes in the remaining fundamental mode waveguides. When the coupled waveguides in the coupled waveguide array 12 are in operation, no power is applied or a reverse bias is applied to generate optical loss due to light absorption.

[0030] The electrical isolation structure 21 is used to achieve electrical isolation between the fundamental mode waveguide array 11 and the coupled waveguide array 12. In some embodiments of the present invention, Figures 1 to 3 The electrical isolation structure 21 penetrates the working layer 2 along the thickness direction of the working layer 2 and contacts the substrate 1. The electrical isolation structure 21 is located between the fundamental mode waveguide array 11 and the coupled waveguide array 12. In other embodiments of the present invention, Figure 4 and Figure 5 The electrical isolation structure 21 may also be disposed in the working layer 2 below the coupling waveguide, and the electrical isolation structure 21 may be an electrical isolation layer extending along the first direction X. Specifically, the active layer in the working layer 2 may face the surface of the substrate 1, or the active layer in the working layer 2 may be away from the surface of the substrate 1. The electrical isolation structure 21 is used to isolate the current diffused from the fundamental mode waveguide to the coupling waveguide, so that the coupling waveguide works without current pumping. Specifically, the electrical isolation structure 21 may be formed by proton implantation and high-energy ion bombardment, or a PN junction designed with a reverse bias, a semi-insulating doped semiconductor material, and an insulating layer prepared by oxidation may be used as the electrical isolation structure 21.

[0031] The optical loss structure 31 is arranged on the coupling waveguide, or in the working layer 2 corresponding to the coupling waveguide. After the coupling waveguide couples the light field distribution of the high-order mode in the fundamental mode waveguide to the coupling waveguide through the same or similar propagation constant, it is suppressed by the optical loss structure 31 to increase the threshold of the high-order mode, thereby obtaining a semiconductor laser device operating in the fundamental mode and at high power.

[0032] In some embodiments of the present invention, reference Figures 1 to 3 , the optical loss structure 31 extends from the coupling waveguide away from the top surface of the substrate 1 to the direction of the substrate 1. It should be noted that the attached embodiment of the present invention provides Figures 1 to 3 An optical loss structure 31 based on an inclined optical groove / light leakage groove is shown. It should be noted that the optical loss structure 31 provided in the embodiment of the present invention is only an example and does not constitute a limitation on the optical loss structure 31. In other embodiments of the present invention, the optical loss structure 31 may also be of other types.

[0033] In some embodiments of the present invention, reference Figure 4 and Figure 5 The optical loss structure 31 is disposed in the working layer 2 below the coupling waveguide, and the optical loss structure 31 extends along the first direction X. Specifically, the optical loss structure 31 may be located on a surface of the active layer in the working layer 2 facing the substrate 1 , or located on a surface of the active layer in the working layer 2 away from the substrate 1 .

[0034] In some embodiments of the present invention, the optical loss structure 31 and the electrical isolation structure 21 may be the same film layer, which is a film layer made of a material having light absorption and electrical insulation, which may be located on the surface of the active layer in the working layer 2 facing the substrate 1, or located on the surface of the active layer in the working layer 2 away from the substrate 1, and which may be a reverse biased PN junction or a semi-insulating high resistance layer made during epitaxial growth. In some examples, the semi-insulating high resistance layer may be an InP material doped with Fe.

[0035] It should be noted that the electrical isolation structure 21 arranged in the working layer 2 below the coupled waveguide does not achieve complete electrical isolation between the fundamental mode waveguide array 11 and the coupled waveguide array 12, but can still reduce the current flow crosstalk between the fundamental mode waveguide array 11 and the coupled waveguide array 12.

[0036] It should be noted that the advantage of the fundamental mode waveguide array 11 provided in the embodiment of the present invention including multiple fundamental mode waveguides is that the area of ​​the gain region of the injected current of the semiconductor laser device can be increased, which is conducive to achieving high-power fundamental mode output. The advantage of the coupled waveguide array 12 provided in the embodiment of the present invention including multiple coupled waveguides is that when the fundamental mode waveguide array 11 includes multiple fundamental mode waveguides, multiple coupled waveguides are set in the coupled waveguide array 12, which can better couple the higher-order modes of the fundamental mode waveguide, thereby achieving high-quality fundamental mode output.

[0037] In the embodiment of the present invention, the coupling waveguide array 12 is located on one side of the fundamental mode waveguide array 11, and the number of coupled waveguides is N-1, where N is an integer greater than 2; or, the two coupling waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the number of coupled waveguides in each coupling waveguide array 12 is N-1, where N is an integer greater than 2; or, the two coupling waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the total number of coupled waveguides in the two coupling waveguide arrays 12 is N-1, where N is an integer greater than 3. The advantages of such a configuration are that, generally speaking, a fundamental mode waveguide array with N fundamental mode waveguides has a plurality of coupling waveguides. The fundamental mode waveguide array 11 has N modes, and the coupled waveguide array 12 has N-1 coupling waveguides, and has N-1 modes. For the fundamental mode waveguide array 11 composed of N fundamental mode waveguides, in addition to the fundamental mode, the other N-1 modes and the N-1 modes of the coupled waveguide array 12 composed of N-1 coupling waveguides have the same or similar propagation constants. In this way, the N-1 high-order optical modes of the fundamental mode waveguide have a higher energy distribution in the coupling waveguide, which is beneficial to improving the coupling of the coupling waveguide array 12 to the high-order modes of the fundamental mode waveguide array 11, and further beneficial to improving the performance of the fundamental mode operation of the semiconductor laser device.

[0038] For the above embodiment, it should be noted that even if the fundamental mode waveguide array 11 and the coupling waveguide are close to each other, since there is no optical mode with the same propagation constant as the fundamental mode of the fundamental mode waveguide in the coupling waveguide, the ratio of the coupling energy of the fundamental mode in the coupling waveguide to the total energy of the fundamental mode is still low. For example, the ratio of the coupling energy of the fundamental mode in the coupling waveguide to the total energy of the fundamental mode can be less than 5%. For all other high-order modes except the fundamental mode, since there is an optical mode with the same propagation constant in the coupling waveguide, the coupling energy of all other high-order modes except the fundamental mode in the coupling waveguide accounts for a high ratio of the energy of the high-order mode. For example, the coupling energy of all other high-order modes except the fundamental mode in the coupling waveguide accounts for more than 5% of the energy of the high-order mode.

[0039] In the first embodiment provided by the present invention, the coupling waveguide array 12 is located at one side of the fundamental mode waveguide array 11 in the first direction X, and each coupling waveguide in the coupling waveguide array 12 has an optical loss structure 31 .

[0040] Specifically, refer to Figure 1 , a working layer 2 is provided on the substrate 1, a fundamental mode waveguide array 11 is located on the side of the working layer 2 away from the substrate 1, the fundamental mode waveguide array 11 includes N fundamental mode waveguides whose widths are not necessarily exactly the same and whose spacings are not necessarily exactly the same, and the fundamental mode waveguide array 11 is energized during operation. In some examples, N can be 4. A coupling waveguide array 12 is provided on the working layer 2, including N-1 coupling waveguides whose widths are not necessarily exactly the same and whose spacings are not necessarily exactly the same, and the fundamental mode waveguide array 11 and the coupling waveguide array 12 are placed side by side. An electrical isolation structure 21 is provided between the fundamental mode waveguide array 11 and the coupling waveguide array 12, so that the currents therebetween will not flow and interfere with each other. Each coupling waveguide has an optical loss structure 31, and the optical loss structure 31 in this embodiment is a high-order grating, which can provide high-order diffraction loss, thereby facilitating the improvement of the threshold current of the high-order mode.

[0041] In the second embodiment provided by the present invention, two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the number of coupled waveguides in each coupled waveguide array 12 is N-1, where N is an integer greater than 2. In some examples, N may be 4. Specifically, refer to Figure 2 , a substrate 1 has a working layer 2, a fundamental mode waveguide array 11 is located on a side of the working layer 2 away from the substrate 1, the fundamental mode waveguide array 11 includes N fundamental mode waveguides whose widths are not necessarily completely the same and whose spacings are not necessarily completely the same, and the fundamental mode waveguide array 11 is energized during operation. A coupling waveguide array 12 is arranged on the working layer 2, including N-1 coupling waveguides whose widths are not necessarily completely the same and whose spacings are not necessarily completely the same, and the coupling waveguide array 12 is placed side by side on opposite sides of the fundamental mode waveguide in the first direction X. An electrical isolation structure 21 is prepared between the fundamental mode waveguide array 11 and the coupling waveguide array 12, so that the currents between the two will not flow and interfere with each other.

[0042] For further reference, Figure 2 The two coupling waveguide arrays 12 are respectively located at opposite sides of the fundamental mode waveguide array 11 in the first direction X, and each coupling waveguide in each coupling waveguide array 12 has an optical loss structure 31 .

[0043] For further reference, Figure 2 , the optical loss structures 31 in the two coupled waveguide arrays 12 on opposite sides of the fundamental mode waveguide array 11 are arranged differently. In other embodiments of the present invention, the optical loss structures 31 on both sides of the fundamental mode waveguide array 11 may also be arranged in the same manner.

[0044] The coupling waveguide array 12 is arranged on the left and right sides of the fundamental mode waveguide array 11, and the coupling waveguide arrays 12 on both sides have the same number of coupling waveguides. The advantage is that the optical field morphology is more symmetrical than that placed on only one side, which helps to improve the cavity surface damage threshold. Specifically, when N is an even number, the strongest point of the optical mode of the symmetrical fundamental mode waveguide array 11 composed of an even number of fundamental mode waveguides should usually be located on the fundamental mode waveguide in the middle of the fundamental mode waveguide array 11. However, due to the presence of the coupling waveguides on both sides, the light intensity at the strongest point of the mode will be reduced, thereby reducing the light field intensity and energy density at the peak position, which in turn increases the cavity surface damage threshold in disguise, making the device less prone to damage. In terms of optical loss, the coupling waveguide arrays 12 on the left and right sides have higher optical losses for high-order modes than the coupling waveguide array 12 placed on only one side. Therefore, the fundamental mode working range and fundamental mode maximum power obtained are higher.

[0045] For further reference, Figure 3 The two coupled waveguide arrays 12 are respectively located at opposite sides of the fundamental mode waveguide array 11 in the first direction X. In each coupled waveguide array 12, except for one coupled waveguide adjacent to the fundamental mode waveguide array 11, each of the remaining coupled waveguides has an optical loss structure 31. The advantage of such a setting is that there is a small amount of fundamental mode distribution on the coupled waveguides close to the fundamental mode waveguide array 11, so optical loss may not be set, which is conducive to preventing the threshold current of the fundamental mode from increasing.

[0046] In the third embodiment provided by the present invention, two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11, and the total number of coupled waveguides of the two coupled waveguide arrays 12 is N-1, where N is an integer greater than 3. In some examples, N may be 6. Specifically, refer to Figure 3 , a substrate 1 has a working layer 2, a fundamental mode waveguide array 11 is located on the side of the working layer 2 away from the substrate 1, the fundamental mode waveguide array 11 includes 6 fundamental mode waveguides whose widths are not necessarily completely the same and whose spacings are not necessarily completely the same, and the fundamental mode waveguide array 11 is energized during operation. A coupling waveguide array 12 is arranged on the working layer 2, wherein the coupling waveguide array 12 on one side includes 2 coupling waveguides whose widths are not necessarily completely the same and whose spacings are not necessarily completely the same, and the coupling waveguide array 12 on the other side includes 3 coupling waveguides whose widths are not necessarily completely the same and whose spacings are not necessarily completely the same, and an electrical isolation structure 21 is provided between the fundamental mode waveguide array 11 and the coupling waveguide array 12, so that the currents therebetween will not flow and interfere with each other. An optical loss structure 31 is provided in the coupling waveguide array 12, and in each coupling waveguide array 12, except for a coupling waveguide adjacent to the fundamental mode waveguide array 11, each of the remaining coupling waveguides has an optical loss structure 31.

[0047] In the fourth embodiment provided by the present invention, referring to Figure 4 , the two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11 in the first direction X, and the number of coupled waveguides in each coupled waveguide array 12 is N-1. Further, along the extension direction of the fundamental mode waveguide, the width of the fundamental mode waveguide in the first direction X gradually increases, and along the extension direction of the coupled waveguide, the width of the coupled waveguide in the first direction X gradually increases. Here, the extension direction of the fundamental mode waveguide and the extension direction of the coupled waveguide refer to the same direction.

[0048] In the fifth embodiment provided in the embodiment of the present invention, reference Figure 5 , the two coupled waveguide arrays 12 are respectively located on opposite sides of the fundamental mode waveguide array 11 in the first direction X, and the number of coupled waveguides in each coupled waveguide array 12 is N-1. Further, the fundamental mode waveguide has a first end, a first middle portion, and a second end arranged along the extension direction, the size of the fundamental mode waveguide in the first direction X gradually decreases from the first end to the middle portion, and the size of the fundamental mode waveguide in the first direction X gradually decreases from the second end to the middle portion; the coupled waveguide has a third end, a second middle portion, and a fourth end arranged along the extension direction, the size of the coupled waveguide in the first direction X gradually decreases from the third end to the second middle portion, and the size of the coupled waveguide in the first direction X gradually decreases from the fourth end to the second middle portion.

[0049] For the fourth embodiment and the fifth embodiment, the semiconductor laser device has the following configuration: a working layer 2 is provided on the substrate 1, a fundamental mode waveguide array 11 is located on the side of the working layer 2 away from the substrate 1, and the fundamental mode waveguide array 11 includes N fundamental mode waveguides with gradually changing widths and spacings, and this part is energized during operation. A coupling waveguide array 12 is provided on the working layer 2, wherein the coupling waveguide array 12 includes N-1 coupling waveguides with gradually changing widths and spacings, and the coupling waveguide array 12 is provided on both sides of the fundamental mode waveguide array 11 in the first direction X. An electrical isolation structure 21 and an optical loss structure 31 are provided in the working layer 2, and the electrical isolation structure 21 prevents the currents between the two from flowing and crosstalking with each other, and the electrical isolation structure 21 and the optical loss structure 31 can be located on the upper and lower surfaces of the active layer, respectively.

[0050] For the fourth embodiment, as the fundamental mode waveguide / coupling waveguide extends, the widths of the fundamental mode waveguide and the coupling waveguide are gradually changing, and can be gradually widened, so that the optical mode of the fundamental mode gradually expands during the transmission process, but during the transmission process, it is still satisfied that the optical field of the high-order mode is coupled in the coupling waveguide on any cross section perpendicular to the transmission direction.

[0051] The fourth embodiment is to gradually widen in only one of the extending directions, corresponding to a high-power single-mode semiconductor laser amplifier or a single-tapered semiconductor laser. The fifth embodiment is to gradually widen in both extending directions, corresponding to a high-power double-tapered semiconductor laser.

[0052] For the fourth and fifth embodiments, as the width of the waveguide in one / two propagation directions gradually increases, the region of fundamental mode injection current continues to increase, which helps to obtain higher power single-mode laser devices, that is, similar to seed sources and optical amplifier devices.

[0053] The semiconductor laser device provided in the above embodiment is composed of a substrate 1 and a working layer 2 located on the substrate 1, wherein the working layer 2 has a fundamental mode waveguide, a coupling waveguide, an electrical isolation structure 21 and an optical loss structure 31, wherein the fundamental mode waveguide is a powered area, and there is electrical isolation between the fundamental mode waveguide and the coupling waveguide, so that the current loaded in the fundamental mode waveguide rarely or almost never flows into the coupling waveguide, so that the coupling waveguide has no or only very weak electrical pumping, and the coupling waveguide array 12 and the fundamental mode waveguide array 11 are placed side by side, and the coupling waveguide array 12 is located on one side or both sides of the fundamental mode waveguide array 11, and there is an obvious optical coupling relationship between the two, and the energy of the fundamental mode in the coupling waveguide does not exceed 5% of the total energy of the fundamental mode, and other high-order modes have an optical field distribution in the coupling waveguide that is greater than 5% of the energy of the mode. The coupling waveguide is not powered, or there is only a small amount of current diffused from the fundamental mode waveguide. The optical loss structure 31 is prepared in the coupling waveguide or in the working layer corresponding to the coupling waveguide, which is conducive to improving the loss and threshold of the high-order mode.

[0054] 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 the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

[0055] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A semiconductor laser device, characterized in that: include: substrate; A working layer, the working layer is located on the surface of the substrate, a ridge waveguide array is provided on a side of the working layer away from the substrate, the ridge waveguide array includes a fundamental mode waveguide array and a coupled waveguide array, the fundamental mode waveguide array includes N fundamental mode waveguides arranged at intervals along a first direction, the coupled waveguide array includes a plurality of coupled waveguides arranged at intervals along the first direction, the coupled waveguide array is located on at least one side of the fundamental mode waveguide array in the first direction, and at least one of the coupled waveguides has an optical loss structure; An electrical isolation structure, wherein the electrical isolation structure is used to achieve electrical isolation between the fundamental mode waveguide array and the coupled waveguide array; Wherein, the coupled waveguide array is located on one side of the fundamental mode waveguide array, and the number of the coupled waveguides is N-1, where N is an integer greater than 2; or, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array, and the number of the coupled waveguides in each coupled waveguide array is N-1, where N is an integer greater than 2; or, the two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array, and the total number of the coupled waveguides of the two coupled waveguide arrays is N-1, where N is an integer greater than 3.

2. The semiconductor laser device according to claim 1, characterized in that The coupled waveguide array is located at one side of the fundamental mode waveguide array in the first direction, and each of the coupled waveguides in the coupled waveguide array has the optical loss structure.

3. The semiconductor laser device according to claim 1, characterized in that The two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array in the first direction, the total number of coupled waveguides in the two coupled waveguide arrays is N-1, N is an odd number, and the number of coupled waveguides in the two coupled waveguide arrays is the same.

4. The semiconductor laser device according to claim 3, characterized in that Along the extending direction of the fundamental mode waveguide, the width of the fundamental mode waveguide in the first direction gradually increases, and along the extending direction of the coupled waveguide, the width of the coupled waveguide in the first direction gradually increases.

5. The semiconductor laser device according to claim 3, characterized in that: The fundamental mode waveguide has a first end, a first middle portion, and a second end arranged along the extension direction, the size of the fundamental mode waveguide in the first direction gradually decreases from the first end to the middle portion, and the size of the fundamental mode waveguide in the first direction gradually decreases from the second end to the middle portion; The coupled waveguide has a third end, a second middle portion and a fourth end arranged along the extension direction, the size of the coupled waveguide in the first direction gradually decreases from the third end to the second middle portion, and the size of the coupled waveguide in the first direction gradually decreases from the fourth end to the second middle portion.

6. The semiconductor laser device according to claim 1, characterized in that The two coupling waveguide arrays are respectively located at opposite sides of the fundamental mode waveguide array in the first direction, and each coupling waveguide in each coupling waveguide array has the optical loss structure.

7. The semiconductor laser device according to claim 6, characterized in that: The optical loss structures in the two coupled waveguide arrays located on opposite sides of the fundamental mode waveguide array are arranged in different ways.

8. The semiconductor laser device according to claim 1, characterized in that The two coupled waveguide arrays are respectively located on opposite sides of the fundamental mode waveguide array in the first direction. In each of the coupled waveguide arrays, except for one coupled waveguide adjacent to the fundamental mode waveguide array, the remaining coupled waveguides all have the optical loss structure.

9. The semiconductor laser device according to claim 1, characterized in that: The optical loss structure extends from the coupling waveguide away from the top surface of the substrate toward the substrate.

10. The semiconductor laser device according to claim 1, characterized in that The optical loss structure is disposed in the working layer below the coupling waveguide, and a plurality of the optical loss structures are arranged at intervals along the thickness direction of the working layer, and each of the optical loss structures extends along the first direction.

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