A self-locking mode VECSEL mode-locked stable chip packaging device, method and control method

Abstract

The application provides a self-locked mode VECSEL mode-stable chip packaging device, method and control method. The packaging device comprises a gain chip, a metal round sheet and a pressure device. The pressure device is arranged on the lower surface of the metal round sheet and is used for generating pressure to deform the metal round sheet and the gain chip. When the surface deformation focal length of the gain chip reaches one half of the central deformation, the nonlinear equivalent focal length of the gain chip is enhanced, mode stabilization is achieved, and the nonlinear equivalent focal length is adjusted by the surface deformation self-defocusing focal length of the gain chip and the nonlinear Kerr lens focal length determined by the material inside the gain chip. The packaging device has the advantages of simple structure, convenient operation and convenience for stabilizing the output of self-locked mode pulses. The packaging method can achieve stable mode locking at a low power without continuously increasing the pump power to increase the light intensity to achieve a stable mode locking state.

Description

Technical Field

[0001] This invention relates to the field of optoelectronics, and more specifically, to a chip packaging device, method, and control method for stabilizing mode-locked VECSELs. Background Technology

[0002] Ultrashort pulse lasers are widely used in physics, biomedicine, and industry. Currently, the realization of ultrashort pulses mainly employs mode-locked solid-state lasers (DPSSL), mode-locked semiconductor edge-emitting lasers, and mode-locked semiconductor surface-emitting lasers. Mode-locked semiconductor surface-emitting lasers are also known as vertical external cavity surface-emitting lasers (VECSELs). As a novel semiconductor laser, it combines the advantages of mode-locked solid-state lasers and edge-emitting lasers, exhibiting excellent performance in achieving ultrashort pulse output. Mode-locked VECSELs without SESAM, also known as self-mode-locked VECSELs, have a simpler structure. Mode-locking is achieved using simple and easily implemented hard or soft holes within the resonant cavity, eliminating the need for a specific, expensive, and complex SESAM design and avoiding the unique usability of MIXSEL gain chips. However, the theoretical analysis of self-mode-locked VECSELs is still inconclusive. Currently, it is widely accepted that due to the Kerr nonlinear effect inside the gain chip, the n² (nonlinear refractive index) inside the semiconductor gain chip is typically in the range of -(1-10)×10⁻⁶. 12 The magnitude of these particles, typically accompanied by a medium thickness of micrometers, results in a relatively weak nonlinear Kerr effect, necessitating further enhancement to improve mode-locking stability. In Kerr media, increasing the nonlinear refractive index parameter n2 and altering the nonlinear coefficient k can strengthen the Kerr nonlinear effect. Since n2 is fixed and cannot be changed, altering the nonlinear loss coefficient k can enhance the Kerr nonlinear effect. As shown in the expression for k, changing k can be achieved by altering the relative instantaneous light intensity change to the size of the light spot at a specific location within the cavity.

[0003] Currently reported methods for stabilizing self-locking VECSELs only involve achieving self-locking through rigorous design of the resonant cavity structure. However, the pump power in the mode-locking stable region is limited to a certain range, and the threshold pump power for self-locking is also relatively high. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] To address the aforementioned problems, this invention provides a chip packaging device, method, and control method for stabilizing mode-locked VECSELs. By introducing strain into the gain chip to change its equivalent focal length, the size of the light spot on the surface of the gain chip is relatively changed, thus solving the problems of instability in mode-locking caused by the weak nonlinear Kerr effect inside the gain chip and the high pump threshold power in the mode-locking region.

[0006] (II) Technical Solution

[0007] The first aspect of this invention provides a self-locking VECSEL mold-locking stable chip packaging device, comprising: a gain chip, which, from top to bottom, includes a surface window layer structure, a multi-quantum well structure, and a DBR reflector structure; a metal circular sheet, the upper surface of which is welded to the gain chip for bearing pressure to cause the gain chip to undergo equivalent deformation synchronously with it; a pressure device disposed on the lower surface of the metal circular sheet for generating pressure to cause deformation of the metal circular sheet and the gain chip, wherein when the surface deformation focal length of the gain chip reaches half of its central deformation, the nonlinear equivalent focal length of the gain chip is enhanced, thereby achieving mold-locking stability; wherein the nonlinear equivalent focal length is adjusted by the focal length of a microlens group composed of the surface deformation self-defocusing focal length of the gain chip and the nonlinear Kerr lens focal length determined by its material.

[0008] In one embodiment of the present invention, the pressure device includes: at least one electrically operated telescopic rod, vertically disposed on the bottom surface of the metal disc, for connecting and supporting the metal disc; a drive assembly, vertically disposed on the bottom surface of the metal disc opposite to the position of the gain chip, for generating pressure that causes deformation of the metal disc; and a platform disposed at the bottom end of the drive assembly and the at least one electrically operated telescopic rod, for supporting the at least one electrically operated telescopic rod and the drive assembly.

[0009] In one embodiment of the present invention, the driving assembly includes: a driving piston, movably disposed in a through hole at the bottom of the platform; and a metal spring, one end of which is sleeved on the driving piston and the other end of which is connected to the bottom surface of the metal disc, for generating pressure that causes the metal disc to deform under the drive of the driving piston.

[0010] In one embodiment of the present invention, the material of the DBR mirror structure is matched with the GaAs substrate lattice, including GaAs and AlGaAs, and the DBR mirror structure is a periodic structure formed by alternating growth of GaAs and AlGaAs materials.

[0011] In one embodiment of the present invention, the gain chip and the metal wafer are welded together using indium material, and the thickness of the weld layer is 50-100 nm.

[0012] In one embodiment of the present invention, the metal disc is made of copper with high thermal conductivity for efficient heat dissipation.

[0013] A second aspect of this invention provides a method for mold-locking VECSEL-stabilized chip packaging, comprising: fabricating a gain chip, a metal wafer, and a pressure device. The metal wafer is soldered to the bottom surface of the gain chip. The pressure device is then disposed at the bottom of the metal wafer to complete the packaging of the gain chip.

[0014] In one embodiment of the present invention, fabricating the gain chip includes: epitaxially growing an etch barrier layer, a DBR mirror structure, a multiple quantum well structure, and a surface window layer structure sequentially from bottom to top on a substrate. The substrate and the etch barrier layer are then removed to obtain the gain chip.

[0015] In one embodiment of the present invention, the pressure device is fabricated by comprising: at least one electrically operated telescopic rod, a drive assembly, and a platform. At least one electrically operated telescopic rod, perpendicular to the metal circular sheet, is welded to the bottom surface of the metal circular sheet. An installation platform is provided, and a drive assembly for generating deformation pressure on the metal circular sheet is installed between the platform and the metal circular sheet. The lower ends of the at least one electrically operated telescopic rod and the drive assembly are then mounted onto the platform to obtain the pressure device.

[0016] A third aspect of this invention provides a method for controlling the mode-locking stability of a self-locking VECSEL, comprising: calculating the equivalent focal length of the nonlinear Kerr effect when the gain chip is undeformed in the initial state; driving a pressure device to generate pressure to deform the metal disc and the gain chip, and to generate a self-defocusing focal length on the surface of the gain chip, which can be combined with the nonlinear Kerr lens focal length of the gain chip to form a microlens group focal length; adjusting the focal length of the microlens group until the deformation focal length on the surface of the gain chip reaches half of the deformation at its center, then stopping the driving of the pressure device to achieve mode-locking stability of the self-locking VECSEL.

[0017] (III) Beneficial Effects

[0018] This invention provides a chip packaging device, method, and control method for stabilizing mode-locked VECSELs. By introducing strain into the gain chip to change the equivalent focal length, it achieves a relative change in the size of the light spot on the gain chip surface. This solves the problems of mode-locking instability caused by the weak nonlinear Kerr effect within the gain chip, as well as the high pump threshold power in the mode-locked region. The device has a simple structure, is easy to operate, and facilitates stable output of mode-locked pulses. It is expected to be applied in physics, biomedicine, and industry, such as in ultrafast spectroscopy, nonlinear imaging, metrology, and ultra-micro precision machining.

[0019] In summary, the beneficial effects of the chip packaging apparatus and method for promoting mode-locking stability of VECSELs provided by the embodiments of the present invention can be summarized as follows:

[0020] (1) The packaging device has a simple structure, is easy to operate, and is convenient to stabilize the output of the self-locking pulse.

[0021] (2) This packaging method utilizes the advantages of self-locking VECSEL, which is stable and reliable, has a simple technical structure, and has no inserted components in the cavity.

[0022] (3) This control method achieves stable mode-locking under low power conditions without continuously increasing the pump power to increase the light intensity and achieve stable mode-locking; it can achieve self-mode-locked ultrashort pulse output with a pulse width on the order of femtoseconds and a beam quality of TEM00. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 The illustration shows a schematic diagram of the epitaxial wafer structure of the gain chip in the self-locking VECSEL mode-stabilized chip packaging device provided in an embodiment of the present invention.

[0025] Figure 2 The illustration shows a schematic diagram of the gain chip being soldered onto a thin metal disc in the self-locking VECSEL mold-locking stable chip packaging method provided in an embodiment of the present invention.

[0026] Figure 3 The diagram illustrates a center-point load-driven model of a metal disc in a self-locking VECSEL mold-locking stable chip packaging device provided by an embodiment of the present invention.

[0027] Figure 4 The schematic diagram illustrates the structure of a self-locking VECSEL mold-locking stable chip packaging device provided in an embodiment of the present invention.

[0028] Figure 5 The schematic diagram illustrates the structure of the driving component in the self-locking VECSEL mold-locking stable chip packaging device provided in an embodiment of the present invention.

[0029] [Attached image labels]

[0030] 1-Gain chip; 11-Surface window layer structure; 12-Multi-quantum well structure; 13-DBR mirror structure; 14-Etching barrier layer; 15-Substrate; 2-Metal circular sheet; 3-Pressure device; 31-Electric telescopic rod; 32-Drive assembly; 321-Drive piston; 322-Metal spring; 33-Platform. Detailed Implementation

[0031] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the invention. In the following detailed description, numerous specific details are set forth to provide a thorough understanding of the embodiments of the invention for ease of explanation. However, it will be apparent that one or more embodiments may be practiced without these specific details. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0032] It should be understood that when an element (such as a layer, film, region, or substrate) is described as being "on" another element, the element may be directly on the other element, or there may be an intermediate element present. Furthermore, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element, or "connected" to the other element via a third element.

[0033] The first embodiment of the present invention provides a self-locking VECSEL mold-locking stable chip packaging device, please refer to... Figure 1 , Figure 2 , Figure 4 and Figure 5 The system includes a gain chip 1, which, from top to bottom, comprises a surface window layer structure 11, a multi-quantum well structure 12, and a DBR reflector structure 13; a metal circular sheet 2, the upper surface of which is welded to the gain chip 1 to bear pressure and cause the gain chip 1 to undergo equivalent deformation synchronously; and a pressure device 3, located on the lower surface of the metal circular sheet 2, to generate pressure to cause deformation of the metal circular sheet 2 and the gain chip 1. When the surface deformation focal length of the gain chip 1 reaches half of its central deformation, the nonlinear equivalent focal length of the gain chip 1 is enhanced, achieving mode-locking stability. The nonlinear equivalent focal length is adjusted by the focal length of the microlens group, which is composed of the surface deformation defocusing focal length of the gain chip 1 and the nonlinear Kerr lens focal length determined by the material.

[0034] Based on the above embodiments, the pressure device 3 includes: three electrically operated telescopic rods 31, vertically disposed on the bottom surface of the metal circular sheet 2, for supporting the metal circular sheet 2, and the three electrically operated telescopic rods are distributed in an equilateral triangle with an included angle of 60° between them, which can increase the stability of the entire device; a drive assembly 32, vertically disposed on the bottom surface of the metal circular sheet 2 opposite to the position of the gain chip 1, for generating pressure that causes the metal circular sheet 2 to deform; and a platform 33, disposed at the bottom end of the drive assembly 32 and the three electrically operated telescopic rods 31, for connecting and supporting the three electrically operated telescopic rods 31 and the drive assembly 32. The electrically operated telescopic rods can be individually adjusted in height of the metal circular sheet 2 as needed, or they can work together with the drive assembly 32 to control the magnitude of deformation of the metal circular sheet 2.

[0035] Based on the above embodiments, the driving assembly 32 includes: a driving piston 321, movably disposed within a through hole at the bottom of the platform 33; and a metal spring 322, one end of which is sleeved on the driving piston 321, and the other end connected to the bottom surface of the metal circular sheet 2, used to generate pressure that causes the metal circular sheet 2 to deform under the drive of the driving piston 321. By driving the driving piston 321 to drive the metal spring 322 to cause the metal circular sheet 2 to deform, the deformation of the metal circular sheet 2 can be equivalent to the deformation of the gain chip 1. When the surface deformation focal length of the gain chip 1 reaches half of its central deformation, mode-locking stability can be achieved.

[0036] Based on the above embodiments, the material of the DBR mirror structure 13 is matched with the GaAs substrate lattice, including GaAs and AlGaAs. The DBR mirror structure 13 is a periodic structure formed by alternating growth of GaAs and AlGaAs materials.

[0037] Based on the above embodiments, the gain chip 1 and the metal disc 2 are welded together using indium material, and the thickness of the weld layer is 50-100nm; wherein the material of the metal disc 2 is copper with high thermal conductivity, and copper can be used for efficient heat dissipation.

[0038] This device has a simple structure and is easy to operate, facilitating the stable output of mode-locked pulses. It is expected to be applied in physics, biomedicine, and industry, such as in ultrafast spectroscopy, nonlinear imaging, metrology, and ultra-micro precision machining.

[0039] Another aspect of the present invention provides a chip packaging method for stabilizing the mode-locking of a self-locking VECSEL, please refer to... Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 Including: S1 to S4.

[0040] S1: Fabrication of gain chip 1, metal wafer 2 and pressure device 3.

[0041] S2: A TiPtAu transition layer and an Au layer are sputtered at the bottom of gain chip 1 using a sputtering process.

[0042] S3: A thin metal disc 2 is soldered onto the bottom surface of the gain chip 1 using indium material.

[0043] S4: Place the pressure device 3 at the bottom of the metal disc 2 to complete the packaging of the gain chip 1.

[0044] Based on the above embodiments, the preparation of the gain chip 1 includes: epitaxially growing an etch barrier layer 14, a DBR mirror structure 13, a multiple quantum well structure 12, and a surface window layer structure 11 sequentially from bottom to top on a substrate 15 using metal oxide chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). The substrate 15 and the etch barrier layer 14 are then removed sequentially using a chemical wet etching method to obtain the gain chip 1.

[0045] Based on the above embodiments, the pressure device 3 includes: three electrically operated telescopic rods 31, a drive assembly 32, and a platform 33. Three electrically operated telescopic rods 31, supporting the metal circular sheet 2, are welded to the bottom surface of the metal circular sheet 2, and the three electrically operated telescopic rods 31 are perpendicular to the metal circular sheet 2. An installation platform 33 is provided, and the drive assembly 32, used to generate deformation pressure on the metal circular sheet 2, is installed between the platform 33 and the metal circular sheet 2. The lower ends of the three electrically operated telescopic rods 31 and the drive assembly 32 are mounted onto the platform 33 to obtain the pressure device 3.

[0046] Another aspect of the present invention provides a chip control method for stabilizing the mode-locked self-mode-locked VECSEL, comprising: calculating the nonlinear Kerr effect equivalent focal length when the gain chip 1 is not deformed in the initial state; driving the pressure device 3 to generate pressure to deform the metal circular sheet 2 and the gain chip 1, and to generate a self-defocusing focal length on the surface of the gain chip 1, which can be combined with the nonlinear Kerr effect equivalent focal length of the gain chip 1 to form a microlens group; adjusting the focal length of the microlens group until the deformation focal length on the surface of the gain chip 1 reaches half of the deformation at its center, then stopping the driving of the pressure device 3 to achieve mode-locked stabilization of the self-mode-locked VECSEL.

[0047] When the center deformation of the metal disc 2 is 0, the equivalent focal length f0 of the nonlinear Kerr effect of the gain chip 1 is calculated. Due to the photo-induced refractive index effect inside the gain chip 1, the Gaussian distributed laser beam causes a nonlinear change in the refractive index inside the gain chip, which can be expressed as:

[0048] n = n0 + n2I

[0049] Where n0 represents the linear refractive index of the material, n2 represents the nonlinear refractive index of the medium, and I represents the incident light intensity.

[0050] In GaAs material coefficients, the nonlinear refractive index coefficient n2 is negative. The refractive index inside gain chip 1 exhibits a waveguide structure distribution with a lower center and higher edges, thus introducing a nonlinear phase shift, i.e., a Kerr phase shift, which can be expressed as:

[0051]

[0052] Where I0 represents the initial light intensity of the laser, w represents the beam waist radius (1 / e) of the light spot, and l represents the thickness of the gain medium;

[0053] The nonlinear phase shift is equivalent to the effect of a thin lens in the frequency domain, thus yielding the critical equivalent focal length f0 of the nonlinear Kerr effect. The calculation method is as follows:

[0054]

[0055] Calculations show that the critical equivalent focal length f0 of gain chip 1 is less than 0, exhibiting a self-defocusing phenomenon. The deformed gain chip 1 is equivalent to adding a self-defocusing focal length to the external environment, which, combined with the nonlinear Kerr effect equivalent focal length of the gain chip, forms the focal length of the microlens group. By adjusting the size of the focal length f of the microlens group, the size of the deformation focal length on the surface of the gain chip can be adjusted, which can effectively increase the nonlinear coefficient of the gain chip and promote the stability of self-locking mode.

[0056] In this embodiment, the thickness of the metal circular sheet 2 is d = 5 mm, and the radius is R = 44 mm; the radius of the contact point between the driving component 32 and the metal circular sheet is r = 8.8 mm, and the electric telescopic rod 31 is welded to the outer ring of the circular sheet, with an outer ring radius of R; the force applied by the driving component 32 is F = 100 N. When the center deformation of the metal circular sheet 2 is 0, the equivalent focal length of the nonlinear Kerr effect of the gain chip 1 is f0; changing the value of f0, the focal length f0 of the gain chip 1 is < 0, which manifests as negative focusing of the laser beam (the focal point is inside the gain chip). The beam waist of the semiconductor external cavity surface-emitting laser is on the gain chip. During the multiple round trips of the laser beam in the resonant cavity, the beam waist continuously decreases, exhibiting the self-focusing effect of the laser. By combining the effect of the soft aperture on the surface of gain chip 1, the loss of the central cavity of the laser beam is small, while the weak edge intensity is continuously suppressed due to diffraction loss. Ultimately, only the strongest peak pulse can be selected with the advantage of minimum loss, exhibiting amplitude modulation. This achieves the selection of the laser's cavity mode and realizes the self-mode-locked output of the semiconductor external cavity surface-emitting laser. Adjusting the value of f0 can enhance the nonlinear Kerr effect of gain chip 1, which is equivalent to increasing the nonlinear coefficient K of the gain medium, promoting further stability of the self-mode-locked VECSEL. According to the circular thin-film theory, applying a force F = 100N to gain chip 1, the central deformation is calculated to be y0 = 10.7µm, and the surface deformation focal length of gain chip 1 is y0 / 2 = 5.35µm. The metal circular sheet 2 achieves an upward concave deformation. The deformation of the gain chip 1 (equivalent elastic modulus E is approximately 61 GPa, Poisson's ratio v is 0.36) can be equivalent to the deformation of the metal circular sheet 2 (equivalent elastic modulus E is approximately 330 GPa, Poisson's ratio v is 0.31). That is, the equivalent focal length increases, the mode-locking of the self-mode-locked VECSEL is more stable, the mode-locking start-up pump threshold of the self-mode-locked semiconductor external cavity surface-emitting laser is reduced, and the stable mode-locked working pump region is increased. In this example, the pump threshold is reduced by 1.4 W.

[0057] The chip packaging method provided in this example for promoting mode-locking stability of self-locking VECSELs can also be combined with other experiments, such as with frequency-doubled VECSELs, to achieve frequency-doubled mode-locking stability at the device level.

[0058] Although the invention has been illustrated and described in detail in the accompanying drawings and the foregoing description, such illustrations and descriptions should be considered illustrative or exemplary rather than restrictive.

[0059] Those skilled in the art will understand that the features described in the various embodiments and / or claims of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, the features described in the various embodiments and / or claims of the present invention can be combined and / or combined in various ways 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.

[0060] Although the invention has been shown and described with reference to specific exemplary embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made to the invention without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents. Therefore, the scope of the invention should not be limited to the above embodiments, but should be determined not only by the appended claims but also by their equivalents.

Claims

1. A self-locking VECSEL mold-locking stable chip packaging device, characterized in that, include: The gain chip (1) includes, from top to bottom, a surface window layer structure (11), a multi-quantum well structure (12), and a DBR mirror structure (13); A metal disc (2) with its upper surface welded to the gain chip (1) is used to bear pressure so that the gain chip (1) produces an equivalent deformation in sync with it. A pressure device (3) is provided on the lower surface of the metal disc (2) to generate pressure to deform the metal disc (2) and the gain chip (1); when the surface deformation focal length of the gain chip (1) reaches half of its central deformation, the nonlinear equivalent focal length of the gain chip (1) is enhanced, and mode-locking stability is achieved; wherein, the nonlinear equivalent focal length is adjusted by the focal length of the microlens group composed of the surface deformation self-defocusing focal length of the gain chip (1) and the nonlinear Kerr lens focal length determined by its material.

2. The self-locking VECSEL mold-locking stable chip packaging device according to claim 1, characterized in that, The pressure device (3) includes: At least one electric telescopic rod (31) is vertically disposed on the bottom surface of the metal circular sheet (2) for connecting and supporting the metal circular sheet (2); The driving component (32) is vertically disposed on the bottom surface of the metal disc (2) opposite to the position of the gain chip (1), and is used to generate pressure that causes the metal disc (2) to deform. A platform (33) is located at the bottom end of the drive assembly (32) and the at least one electric telescopic rod (31) for supporting the at least one electric telescopic rod (31) and the drive assembly (32).

3. The self-locking VECSEL mold-locking stable chip packaging device according to claim 2, characterized in that, The driving component (32) includes: The drive piston (321) is movably disposed in a through hole at the bottom of the platform (33); A metal spring (322) is fitted at one end onto the drive piston (321) and at the other end connected to the bottom surface of the metal disc (2). It is used to generate pressure that causes the metal disc (2) to deform under the drive of the drive piston (321).

4. The self-locking VECSEL mold-locking stable chip packaging device according to claim 1, characterized in that, The material of the DBR mirror structure (13) is matched with the GaAs substrate lattice, including GaAs and AlGaAs. The DBR mirror structure (13) is a periodic structure formed by alternating growth of GaAs and AlGaAs materials.

5. The self-locking VECSEL mold-locking stable chip packaging device according to claim 1, characterized in that, The gain chip (1) and the metal disc (2) are welded together using indium material, and the thickness of the weld layer is 50-100 nm.

6. The self-locking VECSEL mold-locking stable chip packaging device according to claim 1, characterized in that, The material of the metal disc (2) is copper with high thermal conductivity.

7. A method for mold-locking stable VECSEL chip packaging, applied to a mold-locking stable VECSEL chip packaging apparatus as described in any one of claims 1 to 6, characterized in that, include: Fabrication of a gain chip (1), a metal wafer (2), and a pressure device (3); A metal circular sheet (2) is welded to the bottom surface of the gain chip (1); The pressure device (3) is placed at the bottom of the metal disc (2) to complete the encapsulation of the gain chip (1).

8. The chip packaging method for stabilizing mode-locked VECSELs according to claim 7, characterized in that, Fabricating the gain chip (1) includes: An etch barrier layer (14), a DBR mirror structure (13), a multi-quantum well structure (12), and a surface window layer structure (11) are epitaxially grown sequentially from bottom to top on the substrate (15). The substrate (15) and the etch barrier layer (14) are removed to obtain the gain chip (1).

9. The chip packaging method for stabilizing mode-locked VECSELs according to claim 7, characterized in that, The preparation of the pressure device (3) includes: At least one electrically operated telescopic pole (31), a drive assembly (32), and a platform (33); At least one electrically operated telescopic rod (31) supporting the metal circular sheet (2) is welded to the bottom surface of the metal circular sheet (2), and the at least one electrically operated telescopic rod (31) is perpendicular to the metal circular sheet (2); An installation platform (33) is set up, and a drive assembly (32) for generating deformation pressure on the metal circular sheet (2) is installed between the platform (33) and the metal circular sheet (2); The pressure device (3) is obtained by mounting the lower end of the at least one electric telescopic rod (31) and the drive assembly (32) onto the platform (33).

10. A method for controlling the mode-locking stability of a self-locking VECSEL, applied to a chip packaging device for mode-locking stability of a self-locking VECSEL as described in any one of claims 1 to 6, characterized in that, include: Calculate the nonlinear Kerr effect equivalent focal length when the gain chip (1) has not deformed in the initial state; The driving pressure device (3) generates pressure to deform the metal disc (2) and the gain chip (1), and to generate a self-defocusing focal length on the surface of the gain chip (1). This self-defocusing focal length can be combined with the nonlinear Kerr lens focal length of the gain chip (1) to form the focal length of the microlens group. Adjust the focal length of the microlens group so that the surface deformation focal length of the gain chip (1) reaches half of its central deformation, then stop driving the pressure device (3) to achieve VECSEL mode-locking stability.

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