Semiconductor laser and method for controlling the same

Abstract

The application provides a semiconductor laser and a regulation method thereof. The semiconductor laser comprises a substrate, an echo wall microcavity arranged on the substrate, a projection profile of the echo wall microcavity on the substrate is composed of a plurality of curves, the plurality of curves make photons in the echo wall microcavity form a loop after multiple total reflections, and an ohmic contact layer arranged on the echo wall microcavity, an ohmic contact window is formed on the ohmic contact layer, the ohmic contact window makes the ohmic contact layer inject a non-uniform current into the echo wall microcavity, and the non-uniform current is used for regulating a quantity ratio of different mode photons in the echo wall microcavity. The semiconductor laser of the application can increase a direct modulation bandwidth of the semiconductor laser by adjusting a curve parameter of the echo wall microcavity to adjust a mode interval and an intensity difference, and effectively improve a high-speed performance of the laser.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optical fiber communication and semiconductor laser technology, and in particular to a semiconductor laser and a method for regulating the same. BACKGROUND

[0002] With the development of high-speed Internet and Internet of Things technology, the performance requirements of optical sources for communication systems are becoming higher and higher. The construction of new generation data centers and 5G networks needs to handle massive data, and semiconductor lasers, as the core components of optical communication systems, need to have characteristics such as high-speed modulation, low power consumption, high reliability, and compact size. One important indicator of direct modulation lasers is high-speed performance, and one indicator of high-speed performance is the modulation bandwidth of semiconductor lasers. The larger the modulation bandwidth, the greater the signal frequency of the modulation signal that can be tolerated, and the faster the rate. The main means to improve the modulation bandwidth of the laser is to start from improving the relaxation resonance frequency, reducing the parasitic parameters, and starting from optical-optical resonance.

[0003] Compared with other means, optical-optical resonance can effectively broaden the modulation bandwidth, but it is also relatively difficult to achieve. Photon-photon resonance refers to the energy exchange between different modes, and by precisely controlling the mode spacing and intensity difference, the small signal response bandwidth of the laser can be significantly expanded. However, current solutions mostly rely on optical injection locking and complex feedback systems, which not only increase the cost and complexity of the system, but also put higher requirements on the manufacturing process. Microcavity lasers have attracted much attention in recent years because they can utilize the interaction between different modes in the same cavity structure to produce optical-optical resonance. By using whispering gallery mode (WGM) lasing, this type of laser can achieve high photon density and fast signal response.

[0004] Therefore, it is necessary to invent a laser that utilizes optical-optical resonance in a single cavity to improve high-speed performance. SUMMARY

[0005] Therefore, the present application provides a high-speed semiconductor laser with a whispering gallery microcavity, which adjusts the mode spacing and mode intensity difference between the modes inside the single cavity by adjusting the parameters in the whispering gallery microcavity, thereby greatly increasing the direct modulation bandwidth of the semiconductor laser.

[0006] In one aspect, the present application provides a semiconductor laser, comprising: a substrate; a whispering gallery microcavity disposed on the substrate, the projection profile of the whispering gallery microcavity on the substrate is composed of a plurality of curves, and the plurality of curves make the photons in the whispering gallery microcavity form a loop after multiple total reflections; an ohmic contact layer disposed on the whispering gallery microcavity, the ohmic contact layer has an ohmic contact window formed thereon, the ohmic contact window causes the ohmic contact layer to inject a non-uniform current into the whispering gallery microcavity, and the non-uniform current is used to regulate the proportion of the number of different mode photons in the whispering gallery microcavity.

[0007] According to the embodiment of the present application, the projection profile of the projection is surrounded by two parabolas, the two parabolas have two intersection points and two focal points, the two intersection points are located on the first straight line, and the two focal points are located on the second straight line, the first straight line is perpendicular to the second straight line.

[0008] According to the embodiment of the present application, the focal distances of the two parabolas are equal, and an included angle is formed between the two parabolas, the included angle is defined as an included angle formed by a line connecting one of the two intersection points and one of the two focal points, and the whispering gallery microcavity is further used to change the different mode intervals in the whispering gallery microcavity by adjusting the focal distances and the included angle.

[0009] According to the embodiment of the present application, the semiconductor laser further comprises a waveguide arranged on the substrate and connected to the outer end surface of the whispering gallery microcavity along the first straight line, and the waveguide is used to guide the photons in the whispering gallery microcavity to be emitted directionally.

[0010] According to the embodiment of the present application, the waveguide comprises a straight waveguide, and the straight waveguide guides the photons in the whispering gallery microcavity to be emitted directionally by reducing the light field restriction of the whispering gallery microcavity.

[0011] According to the embodiment of the present application, the light emitting surface of the waveguide comprises an end surface coating structure or a dissociation surface.

[0012] According to the embodiment of the present application, the whispering gallery microcavity comprises a first restriction layer, an active layer and a second restriction layer arranged in sequence on the substrate, wherein the first restriction layer and the second restriction layer are used to restrict the loss of the light field in the vertical direction of the substrate, and the active layer is used to generate photons.

[0013] According to the embodiment of the present application, the semiconductor laser further comprises an electrode arranged on the ohmic contact layer, and the electrode is used to inject non-uniform current into the whispering gallery microcavity through the ohmic contact window.

[0014] According to the embodiment of the present application, the projection shape of the ohmic contact window on the substrate comprises an ellipse, a circle, a square or a rectangle.

[0015] Another aspect of the present application also provides a regulation method of the semiconductor laser suitable for any of the above embodiments, comprising: adjusting the output power of the semiconductor laser by adjusting the size of the whispering gallery microcavity; and adjusting the mode intensity and the mode interval of the semiconductor laser by adjusting the shape and size of the plurality of curves in the whispering gallery microcavity.

[0016] The semiconductor laser and the regulation method thereof according to the embodiment of the present application can increase the direct modulation bandwidth of the semiconductor laser by adjusting the curve parameters of the whispering gallery microcavity to adjust the mode interval and the intensity difference, and effectively improve the high-speed performance of the laser. BRIEF DESCRIPTION OF DRAWINGS

[0017] The above and other objects, features and advantages of the present application will become more apparent from the following description of embodiments of the present application taken in conjunction with the accompanying drawings, in which:

[0018] Figure 1 A spatial structure of a semiconductor laser according to an embodiment of the present application is schematically shown;

[0019] Figure 2 A top view structure of a semiconductor laser according to an embodiment of the present application is schematically shown;

[0020] Figure 3 A relationship between a mode quality factor of an echo-wall microcavity portion of a semiconductor laser according to an embodiment of the present application and a corresponding wavelength is schematically shown;

[0021] Figure 4 A magnetic field amplitude distribution of a fundamental transverse mode and a first-order transverse mode magnetic field amplitude in an echo-wall microcavity of a semiconductor laser according to an embodiment of the present application are schematically shown;

[0022] Figure 5 Quality factors and mode intervals of a fundamental mode and a first-order mode of a semiconductor laser according to an embodiment of the present application at different focal lengths are schematically shown;

[0023] Figure 6 Quality factors and mode intervals of a fundamental mode and a first-order mode of a semiconductor laser according to an embodiment of the present application at different angles are schematically shown;

[0024] Figure 7 Laser spectrum intensity of a semiconductor laser according to an embodiment of the present application at different current ranges is schematically shown; and

[0025] Figure 8 A small signal modulation response curve of a semiconductor laser according to an embodiment of the present application calculated by a rate equation model is schematically shown.

[0026] BRIEF DESCRIPTION OF DRAWINGS

[0027] 1 - echo-wall microcavity

[0028] 2 - waveguide

[0029] 3 - ohmic contact layer

[0030] 4 - substrate

[0031] 5 - second electrode

[0032] 6 - cleaved surface

[0033] 7 - ohmic contact window

[0034] P - focal length

[0035] θ - angle;

[0036] d-width;

[0037] A, B - intersection;

[0038] C, D-focus;

[0039] L1, L2-straight line

[0040] 101-first restriction layer;

[0041] 102-active layer;

[0042] 103-Second restriction layer. DETAILED DESCRIPTION

[0043] The following detailed description of the specific embodiments of the present invention will be provided in conjunction with the accompanying drawings. It should be emphasized that these descriptions are intended to illustrate the present invention only and are not intended to limit the scope of the present invention. For ease of understanding, certain specific details are provided in the following detailed description to assist in a comprehensive understanding of the embodiments of the present invention. However, it is apparent that one or more embodiments of the present invention can still be implemented without these details. In addition, to avoid unnecessary information interference, some descriptions of known structures and technologies are omitted in this disclosure.

[0044] The terms used in this disclosure are used only to describe specific embodiments and are not intended to limit the disclosure in any way. Terms such as "include," "comprising," and the like indicate the presence of related features, steps, operations, or components, but do not exclude the presence or addition of other features, steps, operations, or components.

[0045] Unless otherwise defined, all terms used herein (including technical and scientific terms) should be interpreted according to the meanings commonly understood by those skilled in the art. It is worth noting that these terms should be interpreted according to the context of this specification, rather than in an idealized or rigid manner.

[0046] Figure 1 The figure schematically shows the spatial structure of a semiconductor laser according to an embodiment of the present invention. Figure 2 The top view structure of the semiconductor laser according to the embodiment of the present invention is schematically shown. Figure 1 and Figure 2 In the drawings, the same components are numbered the same.

[0047] like Figure 1 As shown, in some embodiments, the semiconductor laser may include a substrate 4 , a whispering gallery microcavity 1 , and an ohmic contact layer 3 .

[0048] The substrate 4 can be an N-type substrate for example. The whispering gallery microcavity 1 is disposed on the substrate 4, and a projection profile of the whispering gallery microcavity 1 on the substrate 4 can be composed of a plurality of curves, which make the photons in the whispering gallery microcavity 1 form a loop after multiple total reflections. The ohmic contact layer 3 is formed on the whispering gallery microcavity 1, and the ohmic contact window 7 is formed on the ohmic contact layer 3. The ohmic contact window 7 can be formed by removing part of the ohmic contact layer 3 by etching for example. The ohmic contact window 7 can be coaxial or non-coaxial with the whispering gallery microcavity 1, which is not limited in the present application. The ohmic contact window 7 can be adjacent to the upper end surface of the whispering gallery microcavity 1. When the current is injected into the ohmic contact layer 3, the current injected into the whispering gallery microcavity 1 from the ohmic contact layer 3 is non-uniform due to the ohmic contact window 7. The non-uniform current can control the proportion of the number of different mode photons in the whispering gallery microcavity 1, i.e. the nonlinear interaction between different modes, to form optical resonance and widen the modulation bandwidth of the laser. In some embodiments of the present application, the shape of the ohmic contact window 7 can be used to control the mode spacing. The shape of the ohmic contact window 7 includes but is not limited to an oval, a circle, a square, and a rectangle.

[0049] The semiconductor laser of the embodiments of the present application optimizes the design by realizing the resonance effect between photons in the whispering gallery microcavity, thereby ensuring that the laser can stably output single-mode laser, and there is a wavelength difference and an intensity difference between the main mode and the side mode. This structure meets the performance requirements of laser light sources for high-speed optical communication systems, significantly improves the small-signal modulation bandwidth, and improves the large-signal modulation rate.

[0050] In some embodiments of the present application, the whispering gallery microcavity 1 can be wrapped by divinylsiloxane bisbenzocyclobutene. The refractive index of divinylsiloxane bisbenzocyclobutene is less than that of the whispering gallery microcavity 1, which can be used to limit the horizontal loss of light.

[0051] In the process of manufacturing the semiconductor laser of the embodiments of the present application, secondary epitaxy can not be required, and complex active and passive integration technology and hybrid integration technology can not be required. In this way, the semiconductor laser of the embodiments of the present application is easy to manufacture. Figure 1 and Figure 2 As shown in FIGS. 1 and 2, in some embodiments, the projection profile of the whispering gallery microcavity 1 on the substrate 4 can be surrounded by two parabolas, and the two parabolas have two intersection points A and B and two focal points C and D. The two intersection points A and B are located on a first straight line L1, and the two focal points C and D are located on a second straight line L2. The first straight line L1 is perpendicular to the second straight line L2. That is, the cross section of the whispering gallery microcavity 1 can be surrounded by two parabolas, so that the light forms a loop inside and each reflection is a total reflection.

[0052] As shown in FIGS. 1 and 2, in some embodiments, the projection profile of the whispering gallery microcavity 1 on the substrate 4 can be surrounded by two parabolas, and the two parabolas have two intersection points A and B and two focal points C and D. The two intersection points A and B are located on a first straight line L1, and the two focal points C and D are located on a second straight line L2. The first straight line L1 is perpendicular to the second straight line L2. That is, the cross section of the whispering gallery microcavity 1 can be surrounded by two parabolas, so that the light forms a loop inside and each reflection is a total reflection. Figure 2As shown, in some embodiments, the focal lengths P of the two parabolas are equal, and an angle is formed between the two parabolas. The angle is defined as the angle θ formed between one of the two intersection points and the line connecting the two foci. By adjusting the focal length P and the angle θ, the spacing between different modes in the whispering gallery microcavity 1 can be changed, thereby optimizing the coupling output efficiency. Specific examples and data will be used to illustrate this later.

[0053] like Figure 1 and Figure 2 As shown, the semiconductor laser may further include a waveguide 2. The waveguide 2 is provided on the substrate 4 and is connected to the outer end face of the whispering gallery microcavity 1 along the first straight line L1. The waveguide 2 may be used to guide the photons in the whispering gallery microcavity 1 to be emitted in a directional manner. The waveguide 2 may have various shapes, such as an arc shape or a flared shape. Figure 2 As shown, in some embodiments, waveguide 2 can also be a straight waveguide with its central axis aligned with the axis of symmetry of the double-parabolic whispering gallery structure. This straight waveguide can guide the directional emission of photons from the whispering gallery microcavity by reducing the light field confinement of the whispering gallery microcavity. In some embodiments, the end face of waveguide 2 can be a dissociation surface, or a film can be coated on the dissociation surface to enhance the dissociation effect.

[0054] like Figure 1 As shown, the whispering gallery microcavity 1 can be an active stacked structure. It can include: a first confinement layer 103 located on a substrate 4, which can be used to reduce vertical optical radiation loss; an active layer 102 disposed on the first confinement layer 103, which can be used for light generation; and a second confinement layer 101 located on the active layer 102, which works together with the first confinement layer 103 to enhance light field confinement. The first confinement layer 103 can be an N-type confinement layer, and the second confinement layer 101 can be a P-type confinement layer.

[0055] In some embodiments, the semiconductor laser further includes a first electrode (not shown). The first electrode can be disposed on the ohmic contact layer 3. The first electrode can be used to inject a non-uniform current into the whispering gallery microcavity 1 through the ohmic contact window 7. The first electrode can be a P-plane electrode.

[0056] like Figure 1 As shown, the semiconductor laser may further include a second electrode 5, which is disposed below the substrate 4. The second electrode 5 may match the first electrode. For example, when the first electrode is a P-face electrode, the second electrode 5 may be an N-face electrode.

[0057] In some other examples of the present application, a method for regulating the semiconductor laser is also provided, which can include: adjusting the output power of the semiconductor laser by adjusting the size of the whispering gallery microcavity 1; and adjusting the mode intensity and mode spacing of the semiconductor laser by adjusting the shape and size of the plurality of curves in the whispering gallery microcavity 1. The technical features and corresponding advantages of the semiconductor laser have been described above, and the method for regulating the semiconductor laser has the same technical features and corresponding advantages, which will not be described here again.

[0058] Taking the double parabolic structure of the plurality of curves in the whispering gallery microcavity 1 as an example, the focal length P and the included angle θ can be changed to adjust the mode intensity and mode spacing of the semiconductor laser. In some embodiments, the connection position of the whispering gallery microcavity 1 and the waveguide 2 can also be changed, and the size of the whispering gallery microcavity 1 determines the optical path of the internally totally reflected light, thereby determining the size of the longitudinal mode spacing.

[0059] It should be noted that when the semiconductor laser applied in the optical communication system is a single longitudinal mode laser, the size of the whispering gallery microcavity 1 should not be too large. However, the present application is not limited thereto.

[0060] Figure 3 The relationship between the mode quality factor of the whispering gallery microcavity part of the semiconductor laser according to an embodiment of the present application and the corresponding wavelength is schematically shown.

[0061] In some embodiments of the present application, the example used in the simulation analysis can be a laser structure with a focal length P = 2.6 µm and an angle θ = 60°. As shown in Figure 3 in the wavelength range of 1500-1550 nm, it is observed that there are three groups of longitudinal modes, and the longitudinal mode spacing between each group of longitudinal modes is about 17 nm. Through optical path calculation, the longitudinal mode spacing is basically consistent with the theoretical calculation result. This result shows that the selected semiconductor laser design can achieve the required longitudinal mode spacing, and this design effectively controls the characteristics of the longitudinal modes, and achieves the expected laser output requirements.

[0062] Based on the analysis of these longitudinal modes, each group of longitudinal modes is further studied in detail. Each group of longitudinal modes contains a fundamental mode and a first-order mode, and there is a certain mode spacing and intensity difference between them. As shown in Figure 3 in addition to the fundamental mode and the first-order mode, the quality factor of other modes is less than 4000. This means that, in addition to the fundamental mode and the first-order mode, other modes have less effect on optical resonance, so the effect of high-order modes can be effectively reduced, thereby improving the performance and stability of the laser.

[0063] In particular, the quality factors of the fundamental mode and the first-order mode are 35914 and 7377, respectively, indicating that both of them perform excellently in the optical-optical resonance process and can effectively maintain the energy and stability of the light. Through this design, the influence of non-fundamental modes and non-first-order modes on the light field in the resonant cavity can be minimized, thereby optimizing the efficiency and quality of the laser output, and the performance of the laser is significantly improved, which can meet the high-performance requirements of the light source in practical applications.

[0064] Figure 4 The magnetic field amplitude distribution of the fundamental transverse mode and the first-order transverse mode in the whispering gallery microcavity of the semiconductor laser according to an embodiment of the present application is schematically shown.

[0065] In some embodiments of the present application, the mode field distributions of the fundamental mode and the first-order mode can be as shown in the left and right graphs of Figure 4 As can be seen from Figure 4 , the fundamental mode and the high-order mode are both concentrated at the position of the focal point, and this distribution form helps to enhance the coupling effect between the fundamental mode and the first-order mode. This coupling effect is crucial for realizing optical-optical resonance and can effectively improve the optical performance of the laser, ensuring that the laser can stably output optical signals under different working conditions. Especially in the whispering gallery microcavity structure, by adjusting the mode field distribution, the propagation of the light field in the microcavity can be optimized, thereby improving the efficiency and output quality of the laser.

[0066] In order to further improve the coupling effect of the light and optimize the injection efficiency of the carriers, the ohmic contact window 7 of the square ring structure is designed in the embodiments of the present application. Through this design, the ohmic contact window 7 can have a higher degree of overlap with the mode field distribution of the fundamental mode or the first-order mode in the whispering gallery microcavity 1. This increase in overlap allows carriers to be more effectively injected into the whispering gallery microcavity, thereby improving the efficiency of photon generation. Improving the carrier injection efficiency is a key factor in improving the output power and stability of the laser, especially in the design of high-efficiency light sources.

[0067] In addition, the present application further optimizes the performance of the laser by utilizing the thermal effect of the current. After current injection, the mode spacing of the fundamental mode and the first-order mode in the whispering gallery microcavity 1 can be fine-tuned due to the presence of thermal effect. This feature increases the degree of freedom in adjusting during the current injection process, allowing the laser to maintain good adjustability and adaptability under different working conditions. Through this method, the mode spacing can be accurately adjusted according to the actual application requirements, thereby achieving better control of the laser output wavelength and mode. This flexible adjustment mechanism not only enhances the performance of the semiconductor laser, but also improves its adjustability and stability in practical applications. These innovative designs enable the laser to achieve excellent optical performance in different application scenarios, meeting the demand for high-efficiency and high-stability light sources.

[0068] Figure 5 The quality factors and mode spacings of the fundamental and first-order modes of the semiconductor laser according to an embodiment of the present application are schematically shown at different focal lengths P. Figure 6 The quality factors and mode spacings of the fundamental and first-order modes of the semiconductor laser according to an embodiment of the present application are schematically shown at different angles θ.

[0069] In some embodiments of the present application, the whispering gallery microcavity 1 can be surrounded by a benzocyclobutene material. The benzocyclobutene has a lower refractive index than the whispering gallery microcavity 1, which plays a role of auxiliary total internal reflection. Due to the lower refractive index of benzocyclobutene, a larger refractive index difference is formed between the benzocyclobutene and the whispering gallery microcavity, thereby ensuring the total reflection confinement of the light in the cavity. This design ensures that the light can be effectively transmitted in the whispering gallery microcavity without leaking to the external environment. In addition, the benzocyclobutene has a low dielectric constant, which has a significant effect on reducing the parasitic capacitance generated during high-speed modulation, and can reduce the additional capacitance effect caused by current injection, which is crucial for high-speed modulation characteristics. By reducing the parasitic capacitance, the laser can have a higher response speed under high-speed modulation.

[0070] To optimize the performance of the laser, a semiconductor laser is simulated, and the outermost layer of the semiconductor laser is designed as a perfect matched layer (PML). The role of the PML is to eliminate the influence of boundary reflection on the modes in the cavity. Through this design, interference or mode distortion caused by reflection can be avoided, and the stability of the output mode of the laser can be ensured. In addition, the PML can end the calculation at the boundary of the model, thereby simplifying the calculation process and improving the simulation efficiency.

[0071] To further study the performance of the microcavity laser of this structure, a series of simulation scanning tests of focal length P and angle θ are performed. It is found that these two parameters have a significant impact on the mode spacing of the fundamental and first-order modes. As shown in Figure 5 by fixing the angle θ to 60° and adjusting the value of the focal length P, the mode spacing of the fundamental and first-order modes can be continuously changed between 0.185 nm and 0.3 nm. This adjustment capability is very beneficial for fine control of the output characteristics of the laser, especially in application scenarios that require precise adjustment of mode spacing and intensity difference.

[0072] Further changes in the angle θ are introduced, as shown in Figure 6As shown, when the focal length P is fixed at 2.6 µm and the included angle θ varies around 60°, the mode spacing can also be continuously adjusted. In this way, the laser can adjust the mode spacing under different angle conditions, thereby flexibly controlling the output characteristics. In particular, when the focal length P is 2.6 µm and the included angle is 60°, the laser of this structure can achieve a better mode intensity difference with a mode spacing of about 0.17 nm. This design not only enhances the control ability of the laser, but also improves its stability and performance in practical applications.

[0073] Figure 7 The laser spectrum intensity of the semiconductor laser according to an embodiment of the present application under different current ranges is schematically shown.

[0074] During the process of the laser from lasing to saturation, the mode of the laser will jump. After mode jumping, the lasing mode stabilizes at a position of about 1523 nm. When performing spectral broadening analysis, as shown, Figure 7 it can be observed that there is a side mode beside the main mode, with an intensity about 30 dB lower than that of the main mode. The mode spacing of this side mode is 0.17 nm, which is consistent with the value in the previous simulation results.

[0075] In the current range from 23 mA to 29 mA, the mode spacing of the laser and the intensity difference between the main mode and the side mode change little, showing good stability. This stability is a very important characteristic of the laser in practical applications, especially in high-speed modulation and optical communication systems, where stable mode spacing can ensure the reliability and signal quality of the system.

[0076] This mode stability helps to achieve optical-optical resonance, that is, the laser can maintain a stable output mode under different working conditions, avoiding unstable output or frequency drift due to mode jumping. By controlling the current and optimizing the design, the laser can maintain good performance in a wide range of working conditions, improving its application effect in communication, sensing and other high-precision applications.

[0077] Figure 8 The small signal modulation response curve calculated by the rate equation model of the semiconductor laser according to an embodiment of the present application is schematically shown.

[0078] In some simulated embodiments of the present application, Figure 8 different response curves of the laser are shown. Among them, the black solid line represents the response curve when the laser is single mode, and the -3 dB bandwidth is observed to be 9.5 GHz. When considering that the laser contains both the fundamental mode and the first-order mode, the response curve is shown as the black dashed line. It can be seen that there will be an optical-optical resonance peak behind the optoelectronic resonance peak, which makes the modulation bandwidth of the laser expand from the original 9.5 GHz to 19.5 GHz.

[0079] To sum up, although the above embodiments have explained the technical solutions, advantages and effects of the present application in detail, these embodiments are only for reference and do not limit the application of the present application. Any modification, replacement or improvement that conforms to the spirit and principles of the present application shall be considered as within the protection scope of the present application. Finally, the protection scope of the present application shall be defined according to the content of the claims, including all equivalent technical solutions and reasonable changes.

[0080] In addition, the numerical parameters in the specification and claims are generally approximate values, unless specifically indicated otherwise. When referring to numerical values related to dimensions, ranges, etc., it should be understood that these numerical values can vary within a certain range in actual applications. For example, these numerical values can vary by ±10%, ±5%, ±1%, or ±0.5% in different embodiments. Such a range of variation provides greater flexibility for the present application to adapt to different application requirements and technical environments.

[0081] It is worth mentioning that the features listed in each embodiment and claim of the present application are not the only solution, and the skilled person can make various combinations and improvements without deviating from the basic principles of the present application. These combinations or improvements, even if not explicitly mentioned in the present application, should be included in the protection scope. Therefore, the protection scope of the present application is not limited to the specific embodiments, but includes any reasonable modification, replacement or combination made under the guidance of the technical idea of the present application.

[0082] In summary, although the above embodiments have explained the technical solutions, advantages and effects of the present application in detail, these embodiments are only for reference and do not limit the application of the present application. Any modification, replacement or improvement that conforms to the spirit and principles of the present application shall be considered as within the protection scope of the present application. Finally, the protection scope of the present application shall be defined according to the content of the claims, including all equivalent technical solutions and reasonable changes.

Claims

1. A semiconductor laser, characterized in that include: substrate; A whispering gallery microcavity is disposed on the substrate, wherein the projected profile of the whispering gallery microcavity on the substrate is composed of multiple curves, wherein the multiple curves cause photons in the whispering gallery microcavity to form a loop after multiple total reflections, and the projected profile is surrounded by two parabolas, wherein the two parabolas have two intersections and two foci, wherein the two intersections are located on a first straight line, and the two foci are located on a second straight line, wherein the first straight line is perpendicular to the second straight line, the focal lengths of the two parabolas are equal, and an angle is formed between the two parabolas, wherein the angle is defined as the angle formed by the line connecting one of the two intersections and the two foci. The whispering gallery microcavity is further configured to change the spacing between different modes in the whispering gallery microcavity by adjusting the focal length and the angle. An ohmic contact layer is disposed on the whispering gallery microcavity. An ohmic contact window is formed on the ohmic contact layer. The ohmic contact window enables the ohmic contact layer to inject a non-uniform current into the whispering gallery microcavity. The non-uniform current is used to regulate the ratio of the number of photons of different modes in the whispering gallery microcavity.

2. The semiconductor laser according to claim 1, wherein The semiconductor laser further comprises: A waveguide is provided on the substrate and connected to the outer end surface of the whispering gallery microcavity along the first straight line, and the waveguide is used to guide the photons in the whispering gallery microcavity to be emitted in a directional manner.

3. The semiconductor laser according to claim 2, wherein The waveguide includes a straight waveguide, which guides the photons in the whispering gallery microcavity to be emitted in a directional manner by reducing the light field confinement of the whispering gallery microcavity.

4. The semiconductor laser according to claim 3, wherein The light-emitting surface of the waveguide includes an end-face coating structure or a dissociation surface.

5. The semiconductor laser according to claim 1, wherein The whispering gallery microcavity includes a first confinement layer, an active layer, and a second confinement layer stacked sequentially on the substrate, wherein the first confinement layer and the second confinement layer are used to limit the loss of the light field in a direction perpendicular to the substrate, and the active layer is used to generate the photons.

6. The semiconductor laser according to claim 1, wherein The semiconductor laser further comprises: An electrode is provided on the ohmic contact layer, and is used for injecting the non-uniform current into the whispering gallery microcavity through the ohmic contact window.

7. The semiconductor laser according to claim 1, wherein The projection shape of the ohmic contact window on the substrate includes an ellipse, a circle, a square, and a rectangle.

8. A control method for a semiconductor laser according to any one of claims 1 to 7, characterized in that: include: Adjusting the output power of the semiconductor laser by adjusting the size of the whispering gallery microcavity; The mode intensity and mode interval of the semiconductor laser are adjusted by adjusting the shapes and sizes of the multiple curves in the whispering gallery microcavity.

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