Semiconductor laser and regulation and control method thereof

Abstract

The invention provides a semiconductor laser and a regulation and control method thereof. The semiconductor laser includes: a substrate; the echo wall microcavity is arranged on the substrate, the projection contour of the echo wall microcavity on the substrate is composed of a plurality of curves, and the plurality of curves enable photons in the echo wall microcavity to form a loop after multiple times of total reflection; the ohmic contact layer is arranged on the echo wall microcavity, an ohmic contact window is formed in the ohmic contact layer, the ohmic contact window enables the ohmic contact layer to inject non-uniform current into the echo wall microcavity, and the non-uniform current is used for regulating and controlling the number proportion of photons in different modes in the echo wall microcavity. According to the semiconductor laser, the mode interval and the intensity difference are adjusted by adjusting the curve parameters of the echo wall microcavity, the direct modulation bandwidth of the semiconductor laser can be increased, and the high-speed performance of the laser is effectively improved.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication and semiconductor lasers, and in particular to a semiconductor laser and a control method thereof. Background Art

[0002] With the development of high-speed Internet and Internet of Things technologies, communication systems have increasingly higher requirements for the performance of light sources. The construction of new-generation data centers and 5G networks requires the processing of massive amounts of data. As the core component of optical communication systems, semiconductor lasers need to have characteristics such as high-speed modulation, low power consumption, high reliability, and compact size. An important indicator of directly modulated lasers is high-speed performance, and an indicator that characterizes high-speed performance is the modulation bandwidth of semiconductor lasers. The larger the modulation bandwidth, the greater the signal frequency of the modulated signal that can be tolerated, and the faster the rate. The means to increase the modulation bandwidth of the laser mainly start from increasing the relaxation resonance frequency, reducing parasitic parameters, and optical-to-optical resonance.

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

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

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

[0006] On the one hand, the present invention provides a semiconductor laser, comprising: a substrate; a whispering gallery microcavity, which is arranged on the substrate, and the projection profile of the whispering gallery microcavity on the substrate is composed of a plurality of curves, and the plurality of curves enable photons in the whispering gallery microcavity to form a loop after multiple total reflections; an ohmic contact layer, which is arranged on the whispering gallery microcavity, and an ohmic contact window is formed on the ohmic contact layer, and the ohmic contact window enables 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 quantity ratio of photons of different modes in the whispering gallery microcavity.

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

[0008] According to an embodiment of the present invention, the focal lengths of the two parabolas are equal, and an angle is formed between the two parabolas. The angle is defined as the angle formed by one of the two intersection points and the line connecting the two foci. The whispering gallery microcavity is also used to change the intervals between different modes in the whispering gallery microcavity by adjusting the focal length and the angle.

[0009] According to an embodiment of the present invention, the semiconductor laser further includes: a waveguide disposed on the substrate and connected to the outer end surface of the whispering gallery microcavity along a first straight line, the waveguide being used to guide the photons in the whispering gallery microcavity to be emitted in a directional manner.

[0010] According to an embodiment of the present invention, 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.

[0011] According to an embodiment of the present invention, the light emitting surface of the waveguide includes an end surface coating structure or a dissociated surface.

[0012] According to an embodiment of the present invention, a whispering gallery microcavity includes a first confinement layer, an active layer, and a second confinement layer stacked sequentially on a 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 photons.

[0013] According to an embodiment of the present invention, the semiconductor laser further includes: an electrode disposed on the ohmic contact layer, the electrode being used to inject a non-uniform current into the whispering gallery microcavity through the ohmic contact window.

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

[0015] On the other hand, the present invention also provides a control method for a semiconductor laser applicable to any of the above embodiments, comprising: adjusting the output power of the semiconductor laser by adjusting the size of the whispering gallery microcavity; adjusting the mode intensity and mode spacing of the semiconductor laser by adjusting the shape and size of multiple curves in the whispering gallery microcavity.

[0016] According to the semiconductor laser and control method thereof of the embodiments of the present invention, the mode spacing and intensity difference are adjusted by adjusting the curve parameters of the whispering gallery microcavity, which can increase the direct modulation bandwidth of the semiconductor laser and effectively improve the high-speed performance of the laser. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

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

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

[0020] Figure 3 The relationship between the mode quality factor and the corresponding wavelength of the whispering gallery microcavity portion of the semiconductor laser according to the embodiment of the present invention is schematically shown;

[0021] Figure 4 Schematically showing 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 the embodiment of the present invention;

[0022] Figure 5 Schematically showing the quality factors and mode spacings of the fundamental mode and the first-order mode of the semiconductor laser at different focal lengths according to an embodiment of the present invention;

[0023] Figure 6 Schematically showing the quality factors and mode spacings of the fundamental mode and the first-order mode of the semiconductor laser at different angles according to an embodiment of the present invention;

[0024] Figure 7 schematically shows the laser spectrum intensity of the semiconductor laser under different current ranges according to an embodiment of the present invention; and

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

[0026] Description of reference numerals:

[0027] 1- Whispering gallery microcavity;

[0028] 2- Waveguide;

[0029] 3-Ohmic contact layer;

[0030] 4-substrate;

[0031] 5- second electrode;

[0032] 6-cleavage plane;

[0033] 7-ohm contact window;

[0034] P-focal length;

[0035] θ - angle;

[0036] d – width;

[0037] A, B-intersection points;

[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] Next, the specific implementation of the present invention will be described in detail with reference to the accompanying drawings. It should be emphasized that these descriptions are only for illustration and are not intended to limit the scope of the present invention. For ease of understanding, some specific details are listed in the following detailed description to help fully understand the embodiments of the present invention. However, it is obvious that one or more embodiments of the present invention can still be implemented despite the absence of these details. In addition, to avoid unnecessary information interference, some descriptions of known structures and technologies are omitted in the present invention.

[0044] The terms in the present invention are only used to describe specific embodiments and are not intended to limit the present invention in any way. The terms "include", "comprises", etc. indicate the existence of relevant characteristics, steps, operations or components, but do not exclude the existence or addition of other characteristics, steps, operations or components.

[0045] Unless otherwise defined, all terms (including technical and scientific terms) used herein 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 spatial structure of a semiconductor laser according to an embodiment of the present invention is schematically shown. Figure 2 The top view structure of a semiconductor laser according to an 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 may be, for example, an N-type substrate. The whispering gallery microcavity 1 is disposed on the substrate 4, and the projection profile of the whispering gallery microcavity 1 on the substrate 4 may be composed of a plurality of curves, and the plurality of curves allow the photons in the whispering gallery microcavity 1 to form a loop after multiple total reflections. The ohmic contact layer 3 is formed on the whispering gallery microcavity 1, and an ohmic contact window 7 is formed on the ohmic contact layer 3. For example, the ohmic contact window 7 may be formed after a portion of the ohmic contact layer 3 is removed by an etching method. The ohmic contact window 7 may be coaxial or non-coaxial with the whispering gallery microcavity 1, and the present invention does not limit this. The ohmic contact window 7 may be adjacent to the upper end surface of the whispering gallery cavity 1, and when the ohmic contact layer 3 is injected with current, the current injected into the whispering gallery microcavity 1 by the ohmic contact layer 3 is non-uniform due to the action of the ohmic contact window 7. The non-uniform current can regulate the number ratio of photons of different modes in the whispering gallery microcavity 1, that is, the nonlinear interaction between different modes, to form optical resonance and broaden the modulation bandwidth of the laser. In some embodiments of the present invention, the shape of the ohmic contact window 7 can be used to adjust the mode interval. The shape of the ohmic contact window 7 includes but is not limited to ellipse, circle, square, rectangle.

[0049] The semiconductor laser of the embodiment of the present invention optimizes the design by realizing the resonance effect between photons in the whispering gallery microcavity, ensuring that the laser can stably output single-mode laser light, and there are wavelength and intensity differences between the main mode and the side mode. This structure meets the performance requirements of the laser light source of the high-speed optical communication system, significantly improves the bandwidth response of small signal modulation, and increases the large signal modulation rate.

[0050] In some embodiments of the present invention, the whispering gallery microcavity 1 may be wrapped by divinylsiloxane bisbenzocyclobutene, which has a smaller refractive index than the whispering gallery microcavity 1 and can be used to limit light loss in the horizontal direction.

[0051] In the process of manufacturing the semiconductor laser of the embodiment of the present invention, it is not necessary to use secondary epitaxy, nor is it necessary to use complex active-passive integration technology and hybrid integration technology. In this way, the semiconductor laser of the embodiment of the present invention is easy to manufacture. Figure 1 and Figure 2 As shown, in some embodiments, the projection profile of the whispering gallery microcavity 1 on the substrate 4 can be surrounded by two parabolas, the two parabolas have two intersection points A and B and two foci C and D, the two intersection points A and B are located on a first straight line L1, the two foci C and D are located on a second straight line L2, and the first straight line L1 is perpendicular to the second straight line L2. In other words, the cross section of the whispering gallery microcavity 1 can be surrounded by two parabolas, so that light forms a loop inside, and each reflection is a total reflection.

[0052] like 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, and the angle is defined as the angle θ formed by 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. This will be explained later with specific embodiments and data.

[0053] like Figure 1 and Figure 2 As shown, the semiconductor laser may further include a waveguide 2. The waveguide 2 is disposed on the substrate 4 and connected to the outer end surface 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 a variety of shapes, such as an arc shape or a flared shape. Figure 2 As shown, in some embodiments, the waveguide 2 can also be a straight waveguide, whose central axis is on the symmetry axis of the double parabola structure whispering gallery. The straight waveguide can guide the photons in the whispering gallery microcavity to be directional by reducing the light field limitation of the whispering gallery microcavity. In some embodiments, the end face of the waveguide 2 can be a dissociation surface, or a layer of film can be coated on the dissociation surface to improve the dissociation effect.

[0054] like Figure 1 As shown, the whispering gallery microcavity 1 can be an active stacked structure. The whispering gallery microcavity 1 can include: a first confinement layer 103 located on the substrate 4, which can be used to reduce the light radiation loss in the vertical direction; an active layer 102 arranged 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 the confinement of the light field. 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 in the figure). The first electrode may be disposed on the ohmic contact layer 3. The first electrode may be used to inject a non-uniform current into the whispering gallery microcavity 1 through the ohmic contact window 7. The first electrode may be a P-surface electrode.

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

[0057] In other embodiments of the present invention, a semiconductor laser control method is provided, which may include: adjusting the output power of the semiconductor laser by adjusting the size of the whispering gallery microcavity 1; adjusting the mode intensity and mode interval of the semiconductor laser by adjusting the shape and size of multiple curves in the whispering gallery microcavity 1. The technical features and corresponding beneficial effects of the semiconductor laser have been described in the previous text, and the control method applicable to the semiconductor laser has the same technical features and corresponding beneficial effects, which will not be repeated here.

[0058] Taking the case where the multiple curves in the whispering gallery microcavity 1 are double parabolic structures as an example, the focal length P and the 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. The size of the whispering gallery microcavity 1 determines the optical path of the total internal reflection light, thereby determining the size of the longitudinal mode spacing.

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

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

[0061] In some embodiments of the present invention, the example used in the simulation analysis may be a laser structure with a focal length of P = 2.6 µm and an angle θ of 60°. Figure 3 As shown in the figure, within the wavelength range of 1500-1550 nm, three groups of longitudinal modes are observed, 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 mode 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 the fundamental mode and the first-order mode, and there are certain mode spacing and intensity differences between them. Figure 3 As shown in the figure, except for the fundamental mode and the first-order mode, the quality factors of other modes are all lower than 4000. This means that, except for the fundamental mode and the first-order mode, other modes have little influence on the optical resonance, so the influence of the higher-order mode 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 they perform well in the optical resonance process and can effectively maintain the energy and stability of the light. Through this design, the influence of non-fundamental mode and non-first-order mode on the optical field in the resonant cavity can be minimized, thereby optimizing the efficiency and quality of the laser output, significantly improving the performance of the laser and meeting 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 magnetic field amplitude distribution of the first-order transverse mode in the whispering gallery microcavity of the semiconductor laser according to the embodiment of the present invention are schematically shown.

[0065] In some embodiments of the present invention, the mode field distributions of the fundamental mode and the first-order mode can be respectively as follows: Figure 4 As shown in the left and right figures. Figure 4 It can be seen that both the fundamental mode and the higher-order mode are concentrated at the focal point. This distribution helps to enhance the coupling between the fundamental mode and the first-order mode. This coupling is crucial to achieve optical-optical resonance, and can effectively improve the optical performance of the laser and ensure 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 light coupling effect and optimize the carrier injection efficiency, the embodiment of the present invention designs an ohmic contact window 7 with a square ring structure. Through this design, the ohmic contact window 7 can produce a high 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 enables 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 invention further optimizes the performance of the laser by utilizing the thermal effect of electric current. After current injection, due to the existence of thermal effect, the mode spacing of the fundamental mode and the first-order mode in the whispering gallery microcavity 1 can be fine-tuned. This feature increases the degree of adjustment freedom during current injection, allowing the laser to maintain good adjustability and adaptability under different working conditions. In this way, the mode spacing can be precisely adjusted according to 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 needs of high-efficiency and high-stability light sources.

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

[0069] In some embodiments of the present invention, the whispering gallery microcavity 1 can be surrounded by a benzocyclobutene material. The refractive index of benzocyclobutene is lower than that of the whispering gallery microcavity 1, which plays a role in assisting the total reflection of light. Due to the low refractive index of benzocyclobutene, a large refractive index difference is formed between it and the whispering gallery microcavity, thereby ensuring the total reflection limitation of the light in the cavity. This design ensures that light can be effectively transmitted in the whispering gallery microcavity without leaking to the external environment. In addition, the dielectric constant of benzocyclobutene is low, 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, it can be ensured that the laser has a higher response speed under high-speed modulation.

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

[0071] In order to further study the performance of the microcavity laser with this structure, a series of simulation scanning tests of focal length P and angle θ were carried out. The experiment found that these two parameters have a significant effect on the mode spacing of the fundamental mode and the first-order mode. Figure 5 As shown in the figure, by fixing the angle θ at 60° and adjusting the focal length P, the mode spacing of the fundamental mode and the first-order mode can be continuously changed between 0.185 nm and 0.3 nm. This adjustment capability is very beneficial for finely controlling the output characteristics of the laser, especially in application scenarios where precise adjustment of the mode spacing and intensity difference is required.

[0072] Further introducing the change of angle θ, such as Figure 6As shown in the figure, when the focal length P is fixed at 2.6µm and the angle θ varies around 60°, continuous regulation of the mode spacing can also be achieved. 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 2.6µm and the angle is 60°, the laser of this structure can achieve a good mode intensity difference near the mode spacing of 0.17nm. 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 under different current ranges according to an embodiment of the present invention is schematically shown.

[0074] In the process of laser from lasing to saturation, the laser mode will jump. After the mode jump, the lasing mode is stable at about 1523nm. When performing spectrum broadening analysis, such as Figure 7 As shown in Figure 1, a side mode can be observed next to 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 23mA to 29mA, the laser mode spacing and the intensity difference between the main mode and the side mode change little, showing good stability. This stability is a very important feature of lasers in practical applications, especially in high-speed modulation and optical communication systems, where stable mode spacing can ensure system reliability and signal quality.

[0076] This mode stability helps achieve optical-optical resonance, that is, the laser can maintain a stable output mode under different operating conditions, avoiding output instability or frequency drift caused by mode hopping. By controlling the current and optimizing the design, it is possible to ensure that the laser maintains good performance over a wide range of operating ranges, improving its application in communications, 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 the embodiment of the present invention is schematically shown.

[0078] In some simulated embodiments of the present invention, Figure 8 Different response curves of the laser are shown. The black solid line represents the response curve when the laser is single-mode, and the -3 dB bandwidth is observed to reach 9.5 GHz. When the laser contains both the fundamental mode and the first-order mode, the response curve is shown as the black dotted line. It can be seen that there is an optical-optical resonance peak behind the photoelectric resonance peak. This feature extends the modulation bandwidth of the laser from the original 9.5 GHz to 19.5 GHz.

[0079] So far, the embodiments of the present invention have been described in detail through the accompanying drawings. It should be particularly pointed out that the implementation methods not described in detail in the drawings or the specification are usually common designs or methods in the technical field, which are generally understood by technicians and are therefore not described in detail. These parts that are not explicitly described do not affect the core technology and innovation of the present invention. For each component, structure or method in this article, although a specific implementation method is given in the embodiment, technicians in this field can appropriately adjust or replace it according to actual needs without changing the essence of the invention.

[0080] In addition, the numerical parameters in the specification and claims are usually approximate values ​​unless otherwise specified. When it comes to numerical values ​​such as dimensions and ranges, it should be understood that these numerical values ​​may vary in actual applications. For example, these numerical values ​​may vary by ±10%, ±5%, ±1% or ±0.5% in different embodiments. This range of variation provides greater flexibility for the present invention, enabling it to adapt to different application requirements and technical environments.

[0081] It is worth mentioning that the features listed in the various embodiments and claims of the present invention are not the only solutions. Technicians can make various combinations and improvements without violating the basic principles of the invention. These combinations or improvements should be included in the scope of protection even if they are not explicitly mentioned in the invention. Therefore, the scope of protection of the present invention is not limited to specific implementation methods, but includes any reasonable modification, substitution or combination guided by the technical ideas of the present invention.

[0082] In summary, although the above embodiments explain the technical solutions, advantages and effects of the present invention in detail, these embodiments are only for reference and do not limit the application of the invention. Any modification, replacement or improvement that conforms to the spirit and principle of the present invention shall be deemed to be within the scope of protection of the present invention. Ultimately, the scope of protection of the invention 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 projection profile of the whispering gallery microcavity on the substrate is composed of a plurality of curves, and the plurality of curves enable photons in the whispering gallery microcavity to form a loop after multiple total reflections; An ohmic contact layer is disposed on the whispering gallery microcavity, and 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, and 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, characterized in that The projection profile is surrounded by two parabolas, the two parabolas have two intersection points and two foci, the two intersection points are located on a first straight line, the two foci are located on a second straight line, and the first straight line is perpendicular to the second straight line.

3. The semiconductor laser according to claim 2, characterized in that The focal lengths of the two parabolas are equal, and an angle is formed between the two parabolas. The angle is defined as the angle formed by one of the two intersection points and the line connecting the two foci. The whispering gallery microcavity is also used to change the intervals between different modes in the whispering gallery microcavity by adjusting the focal length and the angle.

4. The semiconductor laser according to claim 2, characterized in that The semiconductor laser further comprises: A waveguide is disposed 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.

5. The semiconductor laser according to claim 4, characterized in that The waveguide comprises a straight waveguide, and the straight waveguide 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.

6. The semiconductor laser according to claim 5, characterized in that The light emitting surface of the waveguide includes an end face coating structure or a dissociation surface.

7. The semiconductor laser according to claim 1, characterized in that 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 vertical direction of the substrate, and the active layer is used to generate the photons.

8. The semiconductor laser according to claim 1, characterized in that The semiconductor laser further comprises: An electrode is disposed on the ohmic contact layer, and the electrode is used to inject the non-uniform current into the whispering gallery microcavity through the ohmic contact window.

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

10. A control method for a semiconductor laser as claimed in any one of claims 1 to 9, 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 plurality of curves in the whispering gallery microcavity.

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