A single-mode vertical cavity surface emitting laser based on quasi-pt symmetry regulation

Abstract

The application discloses a single-mode vertical cavity surface emitting laser based on quasi-PT symmetry regulation, and belongs to the technical field of semiconductor lasers. The laser comprises a substrate, a lower distributed Bragg reflector, an active region, an upper distributed Bragg reflector, a lower electrode, an upper electrode, and a main resonance region and an auxiliary loss region defined in the transverse direction through a buried tunnel junction process, and the auxiliary loss region is provided with an ion implantation high resistance region. Through the transverse evanescent field coupling of the main resonance region and the auxiliary loss region, the ion implantation high resistance region is combined to make the auxiliary loss region form a relatively high loss area, and quasi-PT symmetry mode regulation is realized based on a mode frequency matching relationship, so that the threshold difference of a target mode and a non-target mode is improved, and stable single-mode output is realized. The application has the advantages of good structure manufacturability and strong mode selectivity.

Description

Technical Field

[0001] This invention relates to the field of semiconductor laser technology, and in particular to a single-mode vertical cavity surface-emitting laser based on quasi-PT symmetric modulation. Background Technology

[0002] Vertical-cavity surface-emitting lasers (VCSELs) are an important type of semiconductor laser. Compared with traditional edge-emitting semiconductor lasers, VCSELs have advantages such as low threshold current, good circular symmetry beam quality, easy two-dimensional array integration, convenient wafer-level testing, and lower manufacturing cost. Therefore, they have been widely used in short-distance optical interconnects, three-dimensional sensing, lidar, consumer electronics, and high-speed optical communication.

[0003] In VCSELs, the longitudinal resonant cavity length is typically only on the order of one wavelength, resulting in a relatively large longitudinal mode spacing, making it relatively easy to achieve single-mode output. However, in the transverse direction, as the device aperture increases or the output power rises, the device often supports the simultaneous oscillation of multiple transverse modes, leading to problems such as mode competition, spectral broadening, side-mode enhancement, increased far-field divergence angle, and decreased beam quality. These issues have become significant factors restricting the further development of VCSELs in high-power, high-speed modulation, and high-coherence output applications. Therefore, effectively suppressing non-target transverse modes, increasing the threshold difference between the target mode and other modes, and achieving stable single-mode output have always been important research directions in the field of VCSELs.

[0004] Existing methods for transverse mode control in VCSELs typically include reducing the current-limiting aperture, employing surface microstructures, introducing additional loss regions, setting asymmetric aperture structures, and using coupling cavities for mode selection. While these methods can improve single-mode output characteristics to some extent, they still have limitations. For example, some methods rely primarily on geometric confinement or uniform additional losses, resulting in insufficient targeting and selectivity in mode selection; while some methods can improve the fundamental mode's competitive advantage, they struggle to simultaneously address structural manufacturability, current injection controllability, and mode stability; and under large aperture or high-power operating conditions, there is still room for further improvement in the suppression of non-target modes.

[0005] On the other hand, buried tunnel junctions (PTJs), as a mature method for current limiting and lateral structure definition in VCSELs, offer advantages such as clear current limiting, controllable lateral dimensions, and benefits for device miniaturization and mode modulation, and have been applied in various VCSEL structures. While the buried tunnel junction process itself is not a newly proposed structural form, it provides a good process platform for realizing lateral composite cavity structures, defining local gain regions, and designing mode selection. Especially when it is necessary to simultaneously define the main operating region and auxiliary region, and apply different injection conditions to different lateral regions, the buried tunnel junction structure has a good foundation for implementation.

[0006] In recent years, non-Hermitian optics and PT symmetry theory have provided new approaches to mode control in semiconductor lasers. By introducing asymmetric gain-loss distributions into the coupled optical system, different modes can exhibit different threshold characteristics and coupling features, thereby achieving selective suppression of non-target modes. However, strict PT symmetry conditions typically place high demands on coupling strength, gain-loss matching, and device structural symmetry, making direct implementation in practical VCSELs quite difficult. In contrast, quasi-PT symmetry control emphasizes achieving mode selection through relative gain-loss distributions and lateral coupling relationships under practically manufacturable conditions, making it more suitable for integration with specific VCSEL structural designs.

[0007] Based on the above, there is an urgent need in the existing technology for a novel VCSEL structure that can effectively suppress multi-mode oscillations and improve single-mode stability under large aperture or high power operating conditions. Summary of the Invention

[0008] The purpose of this invention is to provide a single-mode vertical cavity surface-emitting laser based on quasi-PT symmetric modulation to solve the problems existing in the prior art.

[0009] To achieve the above objectives, the present invention provides a single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation, comprising a substrate, a lower distributed Bragg mirror disposed on the substrate, an active region disposed on the lower distributed Bragg mirror, an upper distributed Bragg mirror disposed on the active region, a lower electrode disposed at the lower part of the lower distributed Bragg mirror, an upper electrode disposed at the upper part of the upper distributed Bragg mirror, a main resonant region and an auxiliary loss region defined in the lateral direction by a buried tunnel junction process, and an ion-implanted high-resistivity region disposed in the auxiliary loss region.

[0010] Preferably, the main resonant region and the auxiliary loss region are defined by etching after a first epitaxy to form a double mesa structure, and a buried tunnel junction structure is formed by a second epitaxy to achieve lateral current limitation.

[0011] Preferably, the ion-implanted high-resistivity region is disposed above and around the auxiliary loss region to suppress current injection into the auxiliary loss region, thereby making the auxiliary loss region a region with higher loss or lower effective gain relative to the main resonant region.

[0012] Preferably, the lateral dimension D of the main resonant region m Lateral dimension D of the auxiliary loss region a Determined based on mode frequency matching relationship, where D m >D a .

[0013] Preferably, the D m and D a Satisfying predetermined frequency matching or approximate frequency matching conditions, such that the characteristic frequency of the target operating mode in the main resonant region is the same as or close to the characteristic frequency of the corresponding mode in the auxiliary loss region, so as to enhance the lateral coupling between the two.

[0014] Preferably, the target operating mode is the fundamental mode of the main resonant region.

[0015] Preferably, by configuring the dimensions of the main resonant region and the auxiliary loss region, as well as the loss loading intensity of the ion implantation high-resistivity region, the net mode gain of the target operating mode first reaches the threshold condition when the material gain is increased.

[0016] Preferably, the active layer corresponding to the main resonant region is used as the gain region, and the active layer corresponding to the auxiliary loss region is used as the fixed loss region, so as to equivalently characterize the low implantation or no implantation state caused by the high resistance region of ion implantation.

[0017] Preferably, there are multiple auxiliary loss regions arranged around the main resonant region, and each auxiliary loss region is provided with the ion implantation high-resistivity region.

[0018] Preferably, the shapes of the main resonant region and the auxiliary loss region include circular, near-circular, or elliptical.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects: This invention provides a single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation. It constructs a lateral coupling system between the main resonant region and the auxiliary loss region on a buried tunnel junction fabrication platform, and combines this with an ion-implanted high-resistivity region to form a relatively high-loss auxiliary region. This achieves selective suppression of non-target modes and preferential oscillation of the target mode. Compared with existing technologies, this invention not only improves the threshold difference between the target and non-target modes but also considers structural manufacturability, current injection controllability, and mode stability. This invention uses a buried tunnel junction structure to define the lateral structure and current limit of the main resonant region and the auxiliary loss region, and then uses an ion-implanted high-resistivity region to suppress current injection in the auxiliary loss region, making the auxiliary loss region a relatively high-loss region with low or no injection. In this way, different modes obtain different degrees of additional loss in the auxiliary loss region, thereby enhancing the competitive advantage of the target mode over the non-target mode. This invention further establishes the relationship between the lateral dimensions of the buried tunnel junction platform and the mode frequency to determine the lateral dimensions of the main platform and the auxiliary platform. This ensures that the target operating mode in the main resonant region and the corresponding mode in the auxiliary loss region meet the frequency matching or approximate frequency matching conditions, thereby enhancing the mode-selective coupling between the main resonant region and the auxiliary loss region. This design method has a clear physical basis and is beneficial for the optimization design of device structural parameters. Simulation results show that in this invention, the fundamental mode can preferentially reach the threshold condition, the out-of-phase supermode subsequently reaches the threshold, while the in-phase supermode remains below the threshold within the indicated gain range. A net mode gain difference of approximately 5 cm⁻¹ is maintained between the fundamental mode and the out-of-phase supermode, indicating that this invention can effectively widen the threshold difference between the target mode and the non-target mode, thus facilitating stable single-mode output. Therefore, the technical solution proposed in this invention has clear feasibility and application prospects. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention.

[0021] Figure 1 This is a schematic diagram of the final structure of the VCSEL based on the secondary epitaxial buried tunnel junction and the ion implantation high-resistivity region to achieve quasi-PT mode control according to the present invention.

[0022] Figure 2 This is a schematic diagram of the double-platform structure formed after one extension of the present invention, wherein (a) is a cross-sectional view and (b) is a top view.

[0023] Figure 3 This is a diagram showing the relationship between the transverse dimensions of the buried tunnel platform and the mode frequency of the present invention.

[0024] Figure 4The diagram shows the characteristic mode distribution and corresponding transverse field profile under the selected size combination of this invention. The left column shows the electric field distribution of different characteristic modes, and A–A′ is the transverse cutoff line set near the active region. The right column shows the transverse normalized Re(Ex) distribution curve extracted along the corresponding A–A′ cutoff line.

[0025] Figure 5 This is a graph showing the relationship between the net mode gain of different characteristic modes of the present invention and the material gain of the main resonant region.

[0026] In the figure: 100, substrate; 200, lower distributed Bragg mirror; 300, active region; 400, main resonant region; 500, auxiliary loss region; 600, upper distributed Bragg mirror; 700, lower electrode; 800, upper electrode; 900, ion implantation high-resistivity region. Detailed Implementation

[0027] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other. The described embodiments are merely some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0028] like Figures 1 to 5 As shown, the present invention provides a single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation, including a substrate 100, a lower distributed Bragg mirror 200 disposed on the substrate 100, an active region 300 disposed on the lower distributed Bragg mirror 200, an upper distributed Bragg mirror 600 disposed on the active region 300, a lower electrode 700 disposed at the lower part of the lower distributed Bragg mirror 200, an upper electrode 800 disposed at the upper part of the upper distributed Bragg mirror 600, a main resonant region 400 and an auxiliary loss region 500 defined in the lateral direction by a buried tunnel junction process, and an ion-implanted high-resistivity region 900 disposed in the auxiliary loss region 500.

[0029] By setting a main resonant region 400 and an auxiliary loss region 500, and suppressing the current injection into the auxiliary loss region 500 through ion implantation of a high-resistivity region 900, the auxiliary loss region 500 can be made to form a region with higher loss or lower effective gain relative to the main resonant region 400. The main resonant region 400 and the auxiliary loss region 500 are coupled through a transverse evanescent field, thereby forming a quasi-PT symmetric mode control structure suitable for vertical cavity surface-emitting lasers, thus achieving selective suppression of non-target modes and preferential oscillation of target modes.

[0030] To further optimize the scheme, the main resonant region 400 and the auxiliary loss region 500 are defined by etching after a first epitaxy to form a double mesa structure, and a buried tunnel junction structure is formed by a second epitaxy to achieve lateral current limitation.

[0031] By defining and forming the main and auxiliary mesa through a first epitaxial etching process, and then performing a second epitaxial process to form a buried tunnel junction, the boundaries and structure of the main resonant region 400 and the auxiliary loss region 500 can be precisely defined in the lateral direction. This provides a reliable structural basis for the subsequent realization of lateral evanescent field coupling between the main resonant region 400 and the auxiliary loss region 500. The formed buried tunnel junction can achieve efficient lateral current confinement, ensuring that the current is mainly confined within the main resonant region 400, thereby enhancing the ability to control the gain region.

[0032] In a further optimized scheme, the ion implantation high-resistivity region 900 is set in the area above and around the auxiliary loss region 500 to suppress the current injection into the auxiliary loss region 500, so that the auxiliary loss region 500 forms a region with higher loss or lower effective gain relative to the main resonant region 400.

[0033] By placing the high-resistivity region 900 of ion implantation in the region above and around the auxiliary loss region 500, the conductivity of the current channel in the auxiliary loss region 500 can be effectively destroyed, and the current injection in this region can be suppressed. This makes it impossible for the active layer in the auxiliary loss region 500 to obtain sufficient gain when it is working, and it may even be a high-loss region. Meanwhile, the main resonant region 400 serves as the main gain region, thereby constructing a precise and controllable gain-loss distribution in the lateral direction. This is the core condition for realizing quasi-PT symmetric mode control.

[0034] Further optimize the scheme, the lateral dimension D of the main resonant region 400 m Lateral dimension D of the auxiliary loss region 500 a Determined based on mode frequency matching relationship, where D m >D a .

[0035] By adjusting the lateral dimension D of the main resonant region 400 m Designed with a lateral dimension D greater than 500 of the auxiliary loss region. a This allows the main resonant region 400 to preferentially support the target operating mode, while the auxiliary loss region 500 supports higher-order modes; by scanning the mode frequency relationships under different lateral dimensions, a specific D can be selected. m and D a The combination allows the target mode in the main resonant region 400 to satisfy the frequency matching or approximate matching condition with a certain mode in the auxiliary loss region 500, thereby enhancing the lateral coupling strength between the two regions and realizing mode-selective energy exchange.

[0036] Further optimize the plan, D m and D a The predetermined frequency matching or approximate frequency matching conditions are met so that the characteristic frequency of the target operating mode in the main resonant region 400 is the same as or close to the characteristic frequency of the corresponding mode in the auxiliary loss region 500, so as to enhance the lateral coupling between the two.

[0037] By making the characteristic frequency of the target operating mode in the main resonant region 400 the same as or close to the characteristic frequency of the corresponding mode in the auxiliary loss region 500, resonant coupling of the specific mode between the two regions can be achieved. This frequency-matching coupling method enables the specific mode to exchange energy efficiently between the two regions, while other modes with unmatched frequencies are coupled weakly. When the auxiliary loss region 500 is configured as high loss, the mode whose frequency matches the target mode in the main resonant region 400 will leak energy into the loss region due to strong coupling, thus being effectively suppressed, while other modes are less affected, thereby achieving the purpose of mode selection.

[0038] The scheme was further optimized, with the target operating mode being the fundamental mode of the main resonant region at 400 Hz.

[0039] By setting the target operating mode to the fundamental mode of the main resonant region 40°, single transverse mode output of a vertical cavity surface-emitting laser can be achieved, especially the fundamental mode output. The fundamental mode has the smallest divergence angle and the highest beam quality, which is the operating mode desired by most applications. Through quasi-PT symmetric control, the competitive advantage of the fundamental mode can be maximized and higher-order modes can be suppressed, thereby achieving high-quality stable single-mode lasing.

[0040] Further optimization of the scheme involves configuring the dimensions of the main resonant region 400 and the auxiliary loss region 500, as well as the loss loading intensity of the ion implantation high-resistivity region 900, so that the net mode gain of the target operating mode first reaches the threshold condition when the material gain is increased.

[0041] By rationally configuring the lateral dimensions of the main resonant region 400 and the auxiliary loss region 500, as well as the loss intensity introduced by the ion implantation high-resistivity region 900, the net mode gain and material gain minus mode loss of different transverse modes can be precisely controlled. Simulations show that under this configuration, as the injection current increases, the material gain of the main resonant region 400 continuously increases. The target operating mode, such as the fundamental mode, will first reach the threshold and begin lasing due to its lowest mode loss. Non-target modes, due to their stronger field distribution in the auxiliary loss region 500, suffer higher additional losses, and their net mode gain is always lower than that of the fundamental mode, thus being effectively suppressed below the threshold.

[0042] To further optimize the scheme, the active layer corresponding to the main resonant region 400 is used as the gain region, and the active layer corresponding to the auxiliary loss region 500 is used as the fixed loss region, so as to equivalently characterize the low implantation or no implantation state caused by the high resistance region 900 of ion implantation.

[0043] By setting the active layer corresponding to the main resonant region 400 as the gain region and setting the active layers corresponding to the auxiliary loss region 500 and the non-main resonant region as the fixed loss region, the low implantation or no implantation state caused by ion implantation high-resistivity region 900 can be accurately and equivalently characterized in the simulation. This equivalent treatment simplifies the simulation model and can effectively analyze the mode competition behavior of different modes in complex transverse structures with gain-loss distribution, providing a theoretical basis for the quasi-PT symmetric control design of actual devices.

[0044] The scheme is further optimized by having multiple auxiliary loss regions 500, which are set around the main resonant region 400, and each auxiliary loss region 500 is equipped with an ion implantation high-resistivity region 900.

[0045] By setting multiple auxiliary loss regions 500 around the main resonant region 400, a symmetrical or asymmetrical loss loading environment can be formed, thereby more effectively controlling non-target modes. Multiple auxiliary loss regions 500 can enhance the strength of lateral coupling and apply different losses to modes at different azimuth angles, further improving mode selectivity. Each auxiliary loss region 500 is equipped with an ion implantation high-resistivity region 900, ensuring that these regions are always in a high-loss state, thereby stably achieving quasi-PT symmetrical control.

[0046] Further optimization of the scheme includes the shapes of the main resonant region 400 and the auxiliary loss region 500, which can be circular, near-circular, or elliptical.

[0047] By designing the main resonant region 400 and the auxiliary loss region 500 as circular, near-circular, or elliptical, different application requirements can be met. Circular structures are isotropic, which is beneficial for obtaining circularly symmetrical output beams. Near-circular or elliptical structures can introduce a certain degree of anisotropy, thereby selectively suppressing modes in specific directions and further optimizing the mode control effect. Different shape choices provide flexibility for device design and optimization.

[0048] The overall implementation process of the single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation provided by this invention is as follows: In the fabrication process, a lower distributed Bragg reflector 200 and an active region 300 are first epitaxially grown sequentially on a substrate 100. Then, a primary mesa and an auxiliary mesa are etched in a predetermined area using a single photolithography and etching process, forming a double-mesa structure. Next, a second epitaxial growth is performed to fill the etched area and continue growing the upper half of the upper distributed Bragg reflector 600. During this process, a buried tunnel junction is formed, which precisely defines the lateral structure of the primary resonant region 400 and the auxiliary loss region 500, achieving efficient lateral current confinement. Subsequently, high-energy ions (such as protons and oxygen ions) are implanted above and around the auxiliary loss region 500 using an ion implantation process, forming an ion-implanted high-resistivity region 900. This disrupts the conductivity of the region, suppresses current injection, and keeps the auxiliary loss region 500 in a low-gain or no-gain high-loss state in the active layer. Finally, a lower electrode 700 and an upper electrode 800 are fabricated to complete the device.

[0049] During device operation, current is injected through the upper electrode 800. Due to the current-limiting effect of the buried tunnel junction, most of the current is confined within the main resonant region 400, driving the active region 300 in this region to generate high gain. However, the auxiliary loss region 500 receives almost no current injection due to the presence of the ion-implanted high-resistivity region 900, resulting in high loss in its corresponding active region. The main resonant region 400 and the auxiliary loss region 500 are coupled through a transverse evanescent field. Crucially, the transverse dimension D of the main resonant region 400... m And the lateral dimension D of the auxiliary loss region 500 a The frequency was carefully selected based on the mode frequency matching relationship, ensuring that the fundamental mode of the main resonant region 400 is close to or matches the frequency of a higher-order mode in the auxiliary loss region 500. Therefore, the higher-order mode has a stronger field distribution in the auxiliary loss region 500, and will leak energy into the high-loss auxiliary loss region 500 through lateral coupling, thus bearing a significant additional loss. The energy of the fundamental mode is mainly localized within the main resonant region 400, with weak coupling to the auxiliary loss region 500, resulting in lower mode loss. As the injected current increases, the material gain of the main resonant region 400 continuously increases. The fundamental mode, due to its net mode gain (material gain - mode loss), reaches the threshold condition first, begins to oscillate, and stabilizes for lasing. Non-target modes (such as higher-order modes, in-phase supermodes, etc.) bear greater additional losses, and their net mode gain remains lower than that of the fundamental mode, effectively suppressed below the threshold. Simulation results are as follows: Figure 5 As shown, it is clearly demonstrated that the fundamental mode reaches the threshold first and maintains a net mode gain difference of about 5 cm⁻¹ with the out-of-phase supermode. This fully proves that the present invention can effectively widen the threshold difference between the target mode and the non-target mode, thereby achieving stable single-mode output.

[0050] In summary, the technical solution provided by this invention cleverly combines buried tunnel junction technology, ion implantation technology, and quasi-PT symmetric mode modulation theory to construct a transversely coupled system between the main resonant region and the auxiliary loss region in a vertical-cavity surface-emitting laser. This solution not only solves the problems of multi-transverse mode oscillation and poor single-mode stability under large aperture or high power conditions in existing technologies, but also overcomes the shortcomings of existing modulation schemes in terms of structural manufacturability and current injection controllability. This invention effectively improves the threshold difference between the target mode and non-target modes, providing a feasible and promising new technical path for high-power, high-speed, and high-beam-quality single-mode vertical-cavity surface-emitting lasers.

[0051] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation, characterized in that, It includes a substrate (100), a lower distributed Bragg mirror (200) disposed on the substrate (100), an active region (300) disposed on the lower distributed Bragg mirror (200), an upper distributed Bragg mirror (600) disposed on the active region (300), a lower electrode (700) disposed at the lower part of the lower distributed Bragg mirror (200), an upper electrode (800) disposed at the upper part of the upper distributed Bragg mirror (600), a main resonant region (400) and an auxiliary loss region (500) defined in the lateral direction by a buried tunnel junction process, and an ion implantation high-resistivity region (900) disposed in the auxiliary loss region (500).

2. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, The main resonant region (400) and the auxiliary loss region (500) are defined by etching after a first epitaxy to form a double mesa structure, and a buried tunnel junction structure is formed by a second epitaxy to achieve lateral current limitation.

3. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, The ion-implanted high-resistivity region (900) is disposed above and around the auxiliary loss region (500) to suppress current injection into the auxiliary loss region (500), thereby making the auxiliary loss region (500) a region with higher loss or lower effective gain relative to the main resonant region (400).

4. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, The lateral dimension D of the main resonant region (400) m The lateral dimension D of the auxiliary loss region (500) a Determined based on mode frequency matching relationship, where D m >D a .

5. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 4, characterized in that, The D m and D a Satisfying predetermined frequency matching or approximate frequency matching conditions, such that the characteristic frequency of the target operating mode in the main resonant region (400) is the same as or close to the characteristic frequency of the corresponding mode in the auxiliary loss region (500), so as to enhance the lateral coupling between the two.

6. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 5, characterized in that, The target operating mode is the fundamental mode of the main resonant region (400).

7. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, By configuring the dimensions of the main resonant region (400) and the auxiliary loss region (500) and the loss loading intensity of the ion implantation high-resistivity region (900), the net mode gain of the target operating mode first reaches the threshold condition when the material gain is increased.

8. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, The active layer corresponding to the main resonant region (400) serves as the gain region, and the active layer corresponding to the auxiliary loss region (500) serves as the fixed loss region, so as to equivalently characterize the low implantation or no implantation state caused by the high-resistivity ion implantation region (900).

9. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, There are multiple auxiliary loss regions (500) arranged around the main resonant region (400), and each auxiliary loss region (500) is provided with the ion implantation high resistance region (900).

10. The single-mode vertical-cavity surface-emitting laser based on quasi-PT symmetric modulation according to claim 1, characterized in that, The shapes of the main resonant region (400) and the auxiliary loss region (500) include circular, near-circular, or elliptical.

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