semiconductor lasers

Abstract

The present invention discloses a semiconductor laser comprising: an N-face electrode; an N-type substrate disposed on the N-face electrode; and a whispering gallery microcavity disposed on the N-type substrate. The whispering gallery microcavity has an octagonal cross-section, comprising a plurality of first curved sides and at least one second curved side. The arc chords of the first and second curved sides are equal, while the arc lengths of adjacent first and second curved sides are unequal, thereby forming two independent sets of fully reflected quadrilateral optical paths within the whispering gallery microcavity. By adjusting the curvature of the curved sides of the whispering gallery microcavity, the wavelength spacing and lasing intensity of the two sets of modes can be further adjusted, significantly increasing the direct modulation bandwidth of the semiconductor laser while maintaining a side mode suppression ratio greater than 30dB.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber communication and semiconductor lasers, and in particular to a large-bandwidth, high-speed, directly modulated semiconductor whispering gallery microcavity laser. Background Art

[0002] With the rapid development of 5G technology, the surge in traffic from personal mobile terminals and home users has placed tremendous pressure on communication systems such as data centers. The continued growth in data volume has placed higher demands on the system's transmission bandwidth and capacity. Optical interconnection, as the core component of communication systems, plays a crucial role in the field of high-speed data transmission. Semiconductor lasers, as carrier light sources in optical communication systems, must possess the following characteristics: wide modulation bandwidth, high output power, good reliability, and long life. In optical communication systems, there are two ways to modulate the output optical carrier of a semiconductor laser: external modulation and direct modulation. External modulation generally uses additional modulators such as LiNbO3 modulators and electro-absorption modulators to modulate the intensity, polarization, and phase of the output light. This modulation method has the characteristics of wide bandwidth and low chirp, but increases system cost and power consumption. Direct modulation directly injects the modulation signal and bias current into the laser to intensity modulate the laser output power. This method does not require additional modulation devices, can significantly reduce system power consumption, and has obvious advantages in practical applications.

[0003] For directly modulated lasers, modulation bandwidth is the most important performance indicator. The larger the bandwidth, the higher the modulation signal frequency and the faster the rate, which means higher efficiency of information transmission. Generally, the modulation bandwidth of the laser is improved by the following methods: increasing the light confinement factor, reducing the volume of the active area, increasing the differential gain, increasing the injection efficiency of the current, etc. It is also possible to introduce a passive feedback area into the DFB laser to increase the modulation response bandwidth through the mode beat effect, or integrate multiple VCSEL resonators together to use mode coupling to produce photon-photon resonance effect. These methods have significantly improved the high-speed modulation characteristics of the laser, but the overall size of the device is large, the power consumption is large, the design and process requirements are relatively high during the preparation process, the stability is poor, and it is not suitable for practical use.

[0004] Therefore, it is necessary to invent a large-bandwidth, high-speed, directly modulated semiconductor laser with good stability, simple preparation, small size, and low power consumption. Summary of the Invention

[0005] To address at least some of the above-mentioned and other technical problems in the prior art, an embodiment of one aspect of the present invention provides a semiconductor laser. By adjusting the curvature of the curved side of the whispering gallery microcavity, the wavelength spacing of light can be further adjusted, thereby significantly increasing the direct modulation bandwidth of the semiconductor laser while maintaining a side mode suppression ratio greater than 30 dB.

[0006] According to an embodiment of one aspect of the present invention, there is provided a semiconductor laser, comprising:

[0007] N-side electrode;

[0008] An N-type substrate is provided on an N-side electrode;

[0009] The whispering gallery microcavity is arranged on an N-type substrate. The cross-section of the whispering gallery microcavity is an octagon, which includes multiple first arcuate sides and at least one second arcuate side. The arc chords of the first arcuate sides and the second arcuate sides are equal, and the arc lengths of adjacent first arcuate sides and second arcuate sides are unequal, so that two sets of independent total reflection quadrilateral light paths are formed in the whispering gallery microcavity.

[0010] In some embodiments of the present invention, arc heights of adjacent first arcuate sides and second arcuate sides are δ1 and δ2, respectively. Where A is the length of the arc chord.

[0011] In some embodiments of the present invention, the ratio of the number of the first arcuate sides to the number of the second arcuate sides is 7:1; or

[0012] The ratio of the number of the first arcuate edges to the number of the second arcuate edges is 6:2, and at least one first arcuate edge is provided between two second arcuate edges; or

[0013] The ratio of the number of first arcuate edges to the number of second arcuate edges is 5:3, and at least one first arcuate edge is provided between two adjacent second arcuate edges; or

[0014] The ratio of the number of the first arc-shaped edges to the number of the second arc-shaped edges is 4:4, and the first arc-shaped edges and the second arc-shaped edges are alternately arranged.

[0015] In some embodiments of the present invention, a through hole is provided in the middle of the whispering gallery microcavity, and the through hole is used to reduce the light confinement capability of the whispering gallery microcavity to increase the output power of the semiconductor laser.

[0016] In some embodiments of the present invention, the whispering gallery microcavity includes:

[0017] An N-type confinement layer is provided on the N-type substrate to reduce the radiation loss of light in the vertical direction;

[0018] an active layer, disposed on the N-type confinement layer, for generating light;

[0019] The P-type confinement layer is provided in the active layer and is used to cooperate with the N-type confinement layer to increase the confinement capability of the light field.

[0020] In some embodiments of the present invention, the semiconductor laser further comprises:

[0021] A waveguide structure is provided on an N-type substrate. The waveguide structure radially extends from the junction of two of the first and second arc-shaped edges of the whispering gallery microcavity. The waveguide structure is used to guide light to be emitted in a directional manner to improve the fiber coupling efficiency of the emitted light.

[0022] In some embodiments of the present invention, the semiconductor laser further comprises:

[0023] The P-side electrode is provided on the whispering gallery microcavity and is used to inject current into the whispering gallery microcavity.

[0024] In some embodiments of the present invention, the shape of the P-side electrode includes any one of the following: square ring, square, circular ring and circle.

[0025] In some embodiments of the present invention, the semiconductor laser further comprises:

[0026] The cleavage surface is provided at the other end of the waveguide structure opposite to the whispering gallery microcavity, and the cleavage surface is used to determine the light emission position.

[0027] In some embodiments of the present invention, the whispering gallery microcavity is surrounded by benzocyclobutene, which has a lower refractive index than the whispering gallery microcavity and is used to assist the whispering gallery microcavity in limiting total reflection of light.

[0028] According to the semiconductor laser of the above-mentioned embodiment of the present invention, by setting the edges of the octagonal structure of the whispering gallery microcavity as arc edges, it is possible to achieve a photon-photon resonance effect within a single whispering gallery microcavity. Through optimized design, stable and controllable single-mode lasing is obtained, meeting the basic requirements of light sources in high-speed optical communication systems, thereby achieving a significant enhancement of the small-signal modulation response bandwidth and a higher large-signal modulation rate corresponding to experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematically shows a three-dimensional structural diagram of a semiconductor laser according to an embodiment of the present invention;

[0030] Figure 2 Schematically shows a top view of a semiconductor laser according to an embodiment of the present invention;

[0031] Figure 3 Schematically shows a schematic diagram of the arc height of a semiconductor laser according to an embodiment of the present invention;

[0032] Figure 4 A diagram schematically shows the corresponding relationship between the quality factor (Q value) and the characteristic wavelength of the whispering gallery microcavity mode of a semiconductor laser according to an embodiment of the present invention;

[0033] Figure 5 Schematic diagrams showing the mode field distribution of the quality factor and characteristic wavelength of the whispering gallery microcavity mode of the semiconductor laser in α and β modes respectively according to an embodiment of the present invention;

[0034] Figure 6 Schematically shows a quality factor distribution diagram of a semiconductor laser at different arc heights according to an embodiment of the present invention;

[0035] Figure 7 A diagram schematically showing the correspondence between the mode wavelength spacing and the refractive index of a semiconductor laser according to an embodiment of the present invention; and

[0036] Figure 8 The diagram schematically shows a small signal modulation response curve of a semiconductor laser calculated using a rate equation model of the semiconductor laser according to an embodiment of the present invention.

[0037] Description of Reference Numerals

[0038] 1- Whispering gallery microcavity;

[0039] 2- waveguide structure;

[0040] 3-Through hole;

[0041] 4-P surface electrode;

[0042] 5-N-type substrate;

[0043] 6-N surface electrode;

[0044] 7-cleavage plane;

[0045] 8- first arcuate side;

[0046] 9-second arcuate side;

[0047] 101-P type confinement layer;

[0048] 102-active layer;

[0049] 103-N type restriction layer. DETAILED DESCRIPTION

[0050] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0051] However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present invention. In the detailed description below, for ease of explanation, many specific details have been set forth to provide a comprehensive understanding of the embodiments of the present invention. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, the description of known techniques has been omitted to avoid unnecessarily confusing the concept of the present invention.

[0052] The terms used herein are only for describing specific embodiments and are not intended to limit the present invention. The term "comprising" used herein indicates the existence of features, steps, operations, but does not exclude the existence or addition of one or more other features.

[0053] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0054] Figure 1 Schematically shows a three-dimensional structural diagram of a semiconductor laser according to an embodiment of the present invention; Figure 2 FIG2 schematically shows a top view of a semiconductor laser according to an embodiment of the present invention.

[0055] According to an embodiment of one aspect of the present invention, there is provided a semiconductor laser, such as Figure 1 、 Figure 2 As shown, it includes: an N-side electrode 6; an N-type substrate 5, which is arranged on the N-side electrode 6; and a whispering gallery microcavity 1, which is arranged on the N-type substrate 5. The cross-section of the whispering gallery microcavity 1 is an octagon, and the octagon includes multiple first arcuate edges 8 and at least one second arcuate edge 9. The arc chords of the first arcuate edges 8 and the second arcuate edges 9 are equal, and the arc lengths of adjacent first arcuate edges 8 and second arcuate edges 9 are not equal, so that two groups of independent total reflection quadrilateral light paths are formed in the whispering gallery microcavity 1.

[0056] The semiconductor laser according to the embodiment of the present invention can realize the photon-photon resonance effect within a single whispering gallery microcavity. Through optimized design, stable and controllable single-mode lasing with significant differences in the wavelength spacing and intensity between the main and side modes can be obtained, meeting the basic requirements of light sources in high-speed optical communication systems, thereby achieving a significant enhancement in the small-signal modulation response bandwidth and a higher large-signal modulation rate corresponding to experience.

[0057] Figure 3 The diagram schematically shows the arc height of a semiconductor laser according to an embodiment of the present invention.

[0058] In some embodiments of the present invention, wherein Figure 3As shown, the arc heights of the adjacent first arcuate side 8 and the second arcuate side 9 are δ1 and δ2 respectively. Where A is the length of the arc chord.

[0059] In some embodiments of the present invention, the ratio of the number of first arcuate edges 8 to second arcuate edges 9 is 7:1; or the ratio of the number of first arcuate edges 8 to second arcuate edges 9 is 6:2, and at least one first arcuate edge 8 is provided between two second arcuate edges 9; or the ratio of the number of first arcuate edges 8 to second arcuate edges 9 is 5:3, and at least one first arcuate edge 8 is provided between two adjacent second arcuate edges 9; or the ratio of the number of first arcuate edges 8 to second arcuate edges 9 is 4:4, and the first arcuate edges 8 and the second arcuate edges 9 are alternately provided. The straight side length A is used to describe the size of the whispering gallery microcavity. The surface area determines the optical path of the internal total reflection light, thereby determining the size of the longitudinal mode spacing. The semiconductor laser used in the optical communication system must be single longitudinal mode lasing, so the straight side length A should not be too large; the arc height δ of the arc side represents the vertical distance between the midpoint of the arc side and the straight side. Different arc heights represent different degrees of deformation of the arc side; R represents the center of the circle corresponding to each arc side.

[0060] Figure 4 The diagram schematically shows the corresponding relationship between the quality factor (Q value) and the characteristic wavelength of the whispering gallery microcavity mode of the semiconductor laser according to an embodiment of the present invention.

[0061] In some embodiments of the present invention, the ratio of the number of the first arcuate sides 8 to the second arcuate sides 9 is 4:4, and the first arcuate sides 8 and the second arcuate sides 9 are alternately arranged. When the straight side length A=8μm, the arc height δ1=0.6μm and δ2=0.32μm are respectively taken, as Figure 4 As shown, two groups of longitudinal modes exist within the wavelength range of 1540-1560 nm, with a longitudinal mode separation of approximately 13 nm, which is consistent with the longitudinal mode separation calculated using the optical path length when the straight side length A = 8 μm. Furthermore, each group of longitudinal modes has two sets of characteristic frequencies, corresponding to two sets of quadrilateral modes. Considering the modes at short wavelengths, defined as α and β modes, they each have two characteristic wavelength solutions with extremely small wavelength differences and different quality factors, representing degenerate modes. Considering the characteristic mode with the larger Q value in each degenerate mode group, the α mode has a wavelength of 1543.51 nm, a Q value of 620265, and an arc height of δ1 = 0.6 μm; the β mode has a wavelength of 1543.29 nm, a Q value of 420883, and an arc height of δ2 = 0.32 μm, with a wavelength separation of 0.22 nm between the two modes.

[0062] In some embodiments of the present invention, a through hole 3 is provided in the center of the whispering gallery microcavity 1. This through hole 3 is used to reduce the light confinement capability of the whispering gallery microcavity 1, thereby increasing the output power of the semiconductor laser. By introducing through hole 3 into the whispering gallery microcavity 1, the Q value of the mode can be reduced under large deformations, increasing the output power of the laser and further improving high-speed modulation characteristics.

[0063] In some embodiments of the present invention, the through hole 3 is used to suppress high-order modes in the whispering gallery microcavity and regulate the quality factor of the intracavity mode. When the arc height of the arc edge is relatively large, the quality factor of the corresponding quadrilateral mode is larger. The internal hole structures of different shapes and sizes can effectively reduce the ability of the resonant cavity to limit light, thereby increasing the ability of the waveguide to couple output light and improve the output power of the laser.

[0064] In some embodiments of the present invention, the whispering gallery microcavity 1 includes: an N-type confinement layer 103, disposed on an N-type substrate 5, for reducing vertical light radiation loss; an active layer 102, disposed on the N-type confinement layer 103, for generating light; and a P-type confinement layer 101, disposed on the active layer 102, for cooperating with the N-type confinement layer 103 to enhance the ability to confine the light field.

[0065] In some embodiments of the present invention, the semiconductor laser further includes a waveguide structure 2 disposed on an N-type substrate 5. The waveguide structure 2 radially extends from the junction of the first curved edge 8 and the second curved edge 9 of the whispering gallery microcavity 1. The waveguide structure 2 is used to guide light emission in a directional manner to improve the fiber coupling efficiency of the emitted light. By designing a vertex-directed connection to the waveguide structure 2, directional laser emission can be achieved, improving the fiber coupling efficiency of the emitted light and facilitating enhanced high-speed modulation characteristics.

[0066] Figure 5 Schematic diagrams of the mode field distribution of the whispering gallery microcavity mode quality factor and characteristic wavelength in α and β modes of a semiconductor laser according to an embodiment of the present invention are schematically shown.

[0067] In some embodiments of the present invention, the ratio of the number of the first arcuate edges 8 to the number of the second arcuate edges 9 is 4:4, and the first arcuate edges 8 and the second arcuate edges 9 are arranged alternately. Figure 5 As shown in the figure, due to the different arc heights of the two groups, the corresponding mode field distributions are somewhat different. Since the arc height δ1 is larger, the light restriction ability is stronger, so the α mode field is more localized in the center of the cavity, while the β mode is relatively divergent in the cavity. The two modes are evenly distributed in the cavity, and the mode field intensity at the vertex is very weak. The direct waveguide has little effect on the mode field. In addition, since the quality factors of the two modes are both 10 5 Therefore, the field distribution in the waveguide is not obvious at this contrast. In actual devices, the direct-connected waveguide structure can effectively increase the coupling output of light.

[0068] Figure 6 The figure schematically shows the quality factor distribution diagram of the semiconductor laser at different arc heights according to an embodiment of the present invention.

[0069] In some embodiments of the present invention, the ratio of the number of the first arcuate edges 8 to the number of the second arcuate edges 9 is 4:4, and the first arcuate edges 8 and the second arcuate edges 9 are alternately arranged. Figure 6 As shown in the figure, when one set of arc heights is fixed at δ1 = 0.6μm and the size of the other set of arc heights δ2 is changed, the corresponding quality factor of the quadrilateral fundamental mode changes. Among them, the black dashed line corresponds to the Q value of the α mode when δ1 = 0.6μm, which is 620265. When the arc heights δ2 are set to 0.14, 0.23, 0.32, 0.41, and 0.51μm, respectively, the wavelength spacing between the two quadrilateral fundamental modes is 20-30GHz, and the corresponding mode Q values ​​are 88327, 31365, 420883, 6308317, and 129259, respectively. Similarly, a microcavity structure based on this arc height combination can achieve the control of wavelength spacing while meeting the standard of single-mode lasers in communication systems with a difference in intensity between the main and secondary modes greater than 30dB.

[0070] In some embodiments of the present invention, the semiconductor laser further comprises: a P-surface electrode 4, which is disposed on the whispering gallery microcavity 1. The P-surface electrode 4 is used to inject current into the whispering gallery microcavity 1. The shape of the P-surface electrode 4 includes any of the following: square ring, square, circular ring and circle.

[0071] In some embodiments of the present invention, by designing the P-side electrode 4 into a square ring structure, the overlap with the mode field distribution of one group of quadrilateral modes in the whispering gallery microcavity 1 can be increased, which is beneficial to improving the carrier injection efficiency. At the same time, the mode spacing between the two groups of quadrilaterals can be further fine-tuned through the thermal effect of the current, thereby increasing the adjustment freedom while injecting current.

[0072] In some embodiments of the present invention, the semiconductor laser further includes: a cleavage surface 7, which is provided at the other end of the waveguide structure 2 opposite to the whispering gallery microcavity 1, and the cleavage surface 7 is used to determine the emission position of light.

[0073] In some embodiments of the present invention, the whispering gallery microcavity 1 is surrounded by benzocyclobutene, which has a lower refractive index than the whispering gallery microcavity 1 and is used to assist in limiting total internal reflection of light within the whispering gallery microcavity 1. Benzocyclobutene has a very low refractive index, creating a high refractive index difference with the cavity, thereby limiting total internal reflection of light within the cavity. Furthermore, this material has a very low dielectric constant, resulting in minimal parasitic capacitance under high-speed modulation characteristics.

[0074] In some embodiments of the present invention, the refractive index of the whispering gallery microcavity is set to 3.2. The cavity is surrounded by BCB (benzocyclobutene), with a refractive index of 1.54, creating a high refractive index difference with the cavity itself, thereby satisfying the total internal reflection restriction for light within the cavity. This material also has a very low dielectric constant, resulting in minimal parasitic capacitance under high-speed modulation characteristics. A perfectly matched layer (PML) is placed on the outermost edge of the semiconductor laser to eliminate the effects of boundary reflections on the intracavity modes and terminate the calculation at the model boundary.

[0075] According to embodiments of the present invention, the semiconductor laser provided by the present invention does not require a passive feedback region or the complex process of integrating multiple coupled cavities. It can simultaneously achieve controllable wavelength spacing and lasing intensity of the lasing mode, effectively increasing the laser's modulation bandwidth through photon-photon resonance. Compared with existing high-speed directly modulated semiconductor lasers, the semiconductor laser of the present invention has advantages such as mode controllability, small size, simple process, high yield, and low cost.

[0076] Figure 7 The corresponding diagram of the mode wavelength spacing and the refractive index of the semiconductor laser according to the embodiment of the present invention is schematically shown.

[0077] In some embodiments of the present invention, Figure 7 As shown in the figure, the refractive index of the annular region of the whispering gallery microcavity 1 is set to 3.2+Δn, and the refractive index of the rest of the region is 3.2. When Δn changes from -0.003 to 0.003, the corresponding Figure 4 The change of the wavelength interval of the two modes α and β is shown in FIG. When Δn = 0, that is, and Figure 4 The results are completely consistent, indicating that under these two sets of arc heights, the two mode separations are the intrinsic 0.22nm (27.5GHz). As the absolute value of Δn increases, the β mode blueshifts to the short wavelength (Δn<0) and redshifts to the long wavelength (Δn>0), and the corresponding mode separation can vary from 0.78nm (97.5GHz) to -0.33nm (-41.25GHz), with an adjustment range much larger than 0.22nm.

[0078] Figure 8 The diagram schematically shows a small signal modulation response curve of a semiconductor laser calculated using a rate equation model of the semiconductor laser according to an embodiment of the present invention.

[0079] In some embodiments of the present invention, Figure 8As shown, the black solid line is the response curve when the laser is single-mode, with a relaxation oscillation frequency of 8.2 GHz, a relaxation oscillation peak height of 1.4 dB, and a -3 dB bandwidth of 15.8 GHz. The black dotted line is the response curve when both α and β coupling modes exist. It can be seen that the relaxation oscillation frequency of the laser itself remains basically unchanged, and the relaxation oscillation peak height decreases by 0.5 dB. After the relaxation oscillation frequency, the rate of decrease of the response curve slows down significantly, and a second resonance peak appears at a center frequency of 26 GHz (corresponding to an interval of 0.22 nm between the α and β modes). At the same time, the depression between the two resonance peaks satisfies >-3 dB, thereby increasing the laser modulation bandwidth from 15.8 GHz to 29 GHz.

[0080] The embodiments of the present invention have been described in detail with reference to the accompanying drawings. It should be noted that any implementations not depicted or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the definitions of the various components described above are not limited to the specific structures, shapes, or methods described in the embodiments; those skilled in the art may easily modify or replace them.

[0081] It should also be noted that, in the specific embodiments of the present invention, unless otherwise indicated, the numerical parameters in this specification and the appended claims are approximate values ​​and can vary depending on the desired properties obtained through the content of the present invention. Specifically, all numbers used in the specification and claims to express compositional dimensions, range conditions, etc. should be understood to be modified by the term "about" in all cases. Generally, the meaning of the expression is to include variations of ±10% in some embodiments, ±5% in some embodiments, ±1% in some embodiments, and ±0.5% in some embodiments from the specific quantity.

[0082] Those skilled in the art will appreciate that various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, even if such combinations and / or combinations are not explicitly described in the present invention. In particular, various combinations and / or combinations of features described in the various embodiments and / or claims of the present invention may be made, without departing from the spirit and teachings of the present invention. All such combinations and / or combinations fall within the scope of the present invention.

[0083] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A semiconductor laser comprising: N-side electrode; An N-type substrate is provided on the N-side electrode; A whispering gallery microcavity is disposed on the N-type substrate, wherein the cross-section of the whispering gallery microcavity is an octagon, the octagon including a plurality of first arcuate sides and at least one second arcuate side, the arc chords of the first arcuate sides and the second arcuate sides being equal, and the arc lengths of adjacent first arcuate sides and second arcuate sides being unequal, so that two sets of independent total reflection quadrilateral light paths are formed in the whispering gallery microcavity; A through hole is provided in the middle of the whispering gallery microcavity, and the through hole is used to reduce the light limiting capability of the whispering gallery microcavity so as to increase the output power of the semiconductor laser.

2. The semiconductor laser according to claim 1, wherein The arc heights of the adjacent first arcuate side and the second arcuate side are respectively and , , where A represents the length of the arc chord.

3. The semiconductor laser according to claim 2, wherein The ratio of the number of the first arcuate sides to the number of the second arcuate sides is 7:1; or The ratio of the number of the first arcuate edges to the number of the second arcuate edges is 6:2, and at least one first arcuate edge is provided between the two second arcuate edges; or The ratio of the number of the first arcuate edges to the number of the second arcuate edges is 5:3, and at least one first arcuate edge is provided between two adjacent second arcuate edges; or The ratio of the number of the first arc-shaped edges to the number of the second arc-shaped edges is 4:4, and the first arc-shaped edges and the second arc-shaped edges are alternately arranged.

4. The semiconductor laser according to claim 1, wherein The whispering gallery microcavity comprises: An N-type confinement layer is provided on the N-type substrate and is used to reduce the radiation loss of light in a vertical direction; an active layer, disposed on the N-type confinement layer, for generating light; The P-type confinement layer is provided on the active layer and is used to cooperate with the N-type confinement layer to increase the confinement capability of the light field.

5. The semiconductor laser according to claim 1, wherein The semiconductor laser further comprises: A waveguide structure is provided on the N-type substrate, wherein the waveguide structure radially extends from the junction of two of the first curved edge and the second curved edge of the whispering gallery microcavity, and the waveguide structure is used to guide light to be emitted in a directional manner to improve the fiber coupling efficiency of the emitted light.

6. The semiconductor laser according to claim 1, wherein The semiconductor laser further comprises: A P-surface electrode is provided on the whispering gallery microcavity, and the P-surface electrode is used to inject current into the whispering gallery microcavity.

7. The semiconductor laser according to claim 6, wherein The P-side electrode shape Includes any of the following: donut, square, doughnut, and circle.

8. The semiconductor laser according to claim 5, wherein The semiconductor laser further comprises: A cleavage surface is provided at the other end of the waveguide structure opposite to the whispering gallery microcavity, and the cleavage surface is used to determine the emission position of light.

9. The semiconductor laser according to claim 1, wherein The whispering gallery microcavity is surrounded by benzocyclobutene, and the refractive index of the benzocyclobutene is lower than that of the whispering gallery microcavity, so as to assist the whispering gallery microcavity in limiting the total reflection of light.

Images