Hermite-Gaussian laser beam generation device

Abstract

This application discloses a Hermitian-Gaussian laser beam generating device, particularly a high-purity one-dimensional Hermitian-Gaussian laser beam generating device, comprising: a laser gain module, a cavity mirror element of a resonant cavity, a laser cavity mode selection element, and a laser mode detection module. The laser gain module is used to achieve stable laser gain; the cavity mirror of the resonant cavity is selected with a suitable output coupling ratio to cooperate with the laser gain module to achieve efficient laser output; the laser cavity mode selection element selects the transverse mode within the laser resonant cavity in two directions; the laser mode detection module is used to observe the envelope of the output beam and adjust the angle of the cavity mirror based on the observation results to introduce detuning into the resonant cavity, while simultaneously adjusting the position of the laser mode selection element to achieve differentiated control of the loss of different orders of cavity modes, ensuring high-purity output of one-dimensional high-order Hermitian-Gaussian laser beams of different orders.

Description

Technical Field

[0001] This application belongs to the field of laser technology, specifically relating to a Hermit-Gaussian laser beam generating device. Background Technology

[0002] Hollow lasers have broad application prospects in quantum optics, optical imaging, laser material processing and optical measurement. Since the mainstream technical approach to obtaining hollow lasers is to perform mode conversion on one-dimensional higher-order Hermitian-Gaussian lasers, obtaining high-power and high-purity one-dimensional higher-order Hermitian-Gaussian lasers has become a research focus in recent years.

[0003] Currently, high-order Hermitian-Gaussian laser beams are mainly obtained through pump light spatial modulation. This involves using a semiconductor coupling module to end-pump a laser crystal via a dichroic mirror. The laser crystal typically employs a small-sized rod-shaped or cuboid structure. Within a fixed resonant cavity structure, a translation stage is used to move the end-pump light up, down, left, and right, thereby exciting and selecting specific spatial modes to generate high-order Hermitian-Gaussian laser beams of different orders. Summary of the Invention

[0004] The purpose of this application is to provide an apparatus for obtaining a Hermitian-Gaussian laser beam.

[0005] According to a first aspect of the embodiments of this application, a generating apparatus is provided, the apparatus comprising: a laser gain module 1, a cavity mirror element 2 of a resonant cavity, a laser cavity mode selection element 3, and a laser mode detection module 4;

[0006] The laser gain module 1 is used to achieve a stable laser gain;

[0007] The cavity mirror element 2 of the resonant cavity is selected with a suitable radius of curvature and output coupling rate to cooperate with the laser gain module to achieve efficient laser output;

[0008] The laser cavity mode selection element 3 selects the transverse mode within the laser resonant cavity in two directions, so that HG is achieved in one direction. 0,0 Basic transverse mode output, HG output in the other direction 0,n Transverse mode output;

[0009] The laser mode detection module 4 is used to observe the envelope of the output light spot, and adjusts the angle of the cavity mirror element 2 according to the observation results to introduce the detuning of the resonant cavity. At the same time, it adjusts the position of the laser mode selection element 3 until a high-purity Hermitian-Gaussian laser mode appears.

[0010] The cavity mirror element 2 and the laser cavity mode selection element 3 of the resonant cavity realize differentiated control of the loss of cavity modes of different orders, thereby ensuring the high purity output of one-dimensional high-order Hermit-Gaussian laser beams of different orders.

[0011] The laser gain module 1 includes a pump laser and coupling submodule 1-a, a gain medium 1-b, and a thermal management module 1-c. The pump laser and coupling submodule 1-a is used to pump the gain medium 1-b and achieve long-term stable laser output under the action of the thermal management module 1-c. The aspect ratio of the gain medium 1-b is not less than 1:5.

[0012] The cavity mirror element 2 of the resonant cavity includes a rear cavity mirror 2-a and an output coupling mirror 2-b; the distance between the cavity mirrors 2 of the resonant cavity and the radius of curvature of the rear cavity mirror 2-a are determined by the beam transmission matrix, and the output coupling mirror 2-b can be selected with different output coupling rates according to the gain characteristics of the selected laser to achieve efficient laser output;

[0013] The laser mode selection element 3 is a strip-shaped mode limiting aperture with adjustable size and position; the laser mode selection element 3 limits the mode along the width and height directions of the gain medium, and the mode limiting aperture size is adjusted to control the mode volume of the output mode;

[0014] The size of the laser mode selection element is calculated based on the fundamental mode size at the aperture calculated from the self-reproducible beam transmission matrix and the theoretical mode size ratio of the required higher-order Hermitian-Gaussian mode to the fundamental mode. This theoretical mode size ratio is obtained through the normalized intensity distribution of the Hermitian-Gaussian mode.

[0015] The theoretical normalized intensity distribution of the Hermit-Gaussian model is determined by the following formula:

[0016]

[0017] in, The theoretical complex amplitude distribution of a Hermitian-Gaussian laser:

[0018]

[0019] Among them, C mn : normalization coefficient; k: wavenumber; z R : is the Rayleigh length of the modulus; z: is the propagation distance of the beam starting from z=0; w(z): is the beam waist at plane z; H m (x) and H n (x): Hermitian polynomials of order m and n, respectively;

[0020] The laser mode selection element 3 has an aperture light transmission size L. x L y Adjustable, but must ensure the basic transverse mode output in one direction, such as the x-direction, i.e., HG. 0,0 The mode, while the other direction is through the aperture L. ySelect the modulus volume, and the corresponding dimension is the HG of the output. 0,n The order of the module n and the size range are as follows:

[0021]

[0022] Among them, the aspect ratio L of the aperture is x :L y In principle, the ratio can be changed from 1:1 to 1:20, α x =1.2~1.5, α y =1.1~1.5; β n : is the theoretical mode size ratio of the higher-order Hermitian-Gaussian mode to the fundamental mode; w0: is the fundamental mode size at the aperture calculated from the self-reproducible beam transmission matrix;

[0023] The laser mode detection module 4 includes a laser attenuation element 4-a and an element 4-b for observing the light spot, which can be a camera, photographic paper, or photosensitive film.

[0024] The pump power of the laser gain module 1, the pitch and yaw angles of the output coupling mirror 2-b, and the position of the laser mode selection element 3 can all be adjusted so that the resonant cavity emits light near the threshold.

[0025] The laser mode detection module is used to observe the envelope and contrast of the output spot, and adjust the pitch angle of the output coupling mirror 2-b and the position of the laser mode selection element 3 according to the observation results until the highest-order Hermitian-Gaussian mode limited by the high-purity laser mode selection element 3 appears.

[0026] The adjustment of the pitch angle of the output coupling mirror 2-b introduces the detuning of the resonant cavity, and differentiates the intracavity mode loss of different orders to output high-purity one-dimensional high-order Hermit-Gaussian laser beams of different orders.

[0027] The high purity refers to the correlation coefficient of a one-dimensional high-order Hermitian-Gaussian laser beam obtained by the device with the theoretical normalized intensity distribution of the corresponding order Hermitian-Gaussian laser, which is not less than 0.8.

[0028] The correlation coefficient is determined by the following formula:

[0029]

[0030] Where, I(i): is the light intensity at each position of the one-dimensional higher-order Hermitian-Gaussian laser beam obtained by the device after being discretized into N positions along the higher-order mode direction; This is the theoretical normalized light intensity at each position after the corresponding order Hermitian-Gaussian laser is discretized into N positions along the higher-order mode direction.

[0031] The gain medium of the laser gain module 1 is a solid gain medium such as a crystal, ceramic or glass doped with excitation ions, or a liquid gain medium a fluid doped with Nd, or a gaseous gain medium such as CO2.

[0032] The gain medium 1-b adopts an asymmetric transverse cross-section design and achieves fundamental mode output through self-limiting mode in one direction.

[0033] Furthermore, there are multiple laser gain modules 1; the multiple laser gain modules 1 are arranged in series.

[0034] Furthermore, the Hermite-Gaussian laser beam generating device also includes a polarizing mirror or uses Brewster angle incident light to achieve laser polarization output.

[0035] Furthermore, a Q-switching or mode-locking device is added to the laser cavity mode selection element 3 to achieve short-pulse HG. 0,n Laser beam output.

[0036] The above-mentioned technical solution of this application has the following beneficial technical effects:

[0037] The device described in this application optimizes the design of the laser resonator and, by controlling the mode selection element and angular detuning within the cavity, differentially modulates the intracavity mode loss of different orders, generating high-purity one-dimensional Hermitian-Gaussian laser beams of different orders. This device and method achieve high-purity one-dimensional high-order Hermitian-Gaussian laser output, and further, hollow spot output can be achieved using mode conversion methods, showing broad application prospects in quantum optics, optical imaging, laser material processing, and optical measurement. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the Hermit-Gaussian laser beam generating device in an exemplary embodiment of this application;

[0039] Figure 2 This is a schematic diagram of the propagation of Hermitian-Gaussian lasers of different orders along the Z direction in an exemplary embodiment of this application;

[0040] Figure 3 This is a schematic diagram comparing the principle of an exemplary embodiment of this application with that of an off-axis pumping method;

[0041] Figure 4 This is an exemplary embodiment of the high-purity HG in this application. 0,4 Light spot pattern;

[0042] Figure 5 This is an exemplary embodiment of the present application where the theoretical calculation and the HG obtained by the method are compared. 0,4 Intensity distribution comparison chart;

[0043] Figure 6 This is an exemplary embodiment of the high-purity HG in this application. 0,4 Beam quality test results. Detailed Implementation

[0044] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to specific embodiments and accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this application. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concepts of this application.

[0045] Obviously, the described embodiments are only a part of the embodiments of this application, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0046] In the description of this application, it should be noted that the terms "first", "second", and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0047] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0048] The inventors discovered that to achieve high-purity Hermitian-Gaussian lasers, it is essential to control the intracavity modes of the laser while ensuring differentiated losses for each mode, thus minimizing the loss of the desired output mode. Currently, high-order Hermitian-Gaussian laser beams are primarily obtained through pump light spatial modulation. This involves end-pumping a laser crystal using a semiconductor coupling module and a dichroic mirror. The laser crystal typically employs a small-sized rod-shaped or cuboid structure. Within a fixed resonant cavity, a translation stage is used to shift the end-pump light vertically and horizontally, exciting and selecting specific spatial modes to generate high-order Hermitian-Gaussian laser beams of varying orders. However, pump light spatial modulation is limited by mode volume, generating effective gain only in the end-pumped portion of the crystal. Furthermore, the rod-shaped structure of the laser medium leads to significant thermal effects, making scaling and amplification difficult. Consequently, the power output of existing high-purity one-dimensional high-order Hermitian-Gaussian lasers obtained through pump light spatial modulation is limited to the hundreds of milliwatts.

[0049] The Hermit-Gaussian laser beam generating device provided in this application will be described in detail below with reference to the accompanying drawings, through specific embodiments and application scenarios.

[0050] like Figure 1As shown, in a first aspect of the embodiments of this application, a Hermitian-Gaussian laser beam generating device is provided, particularly a high-purity one-dimensional Hermitian-Gaussian laser beam generating device, the device comprising: a laser gain module 1, a cavity mirror element 2 of a resonant cavity, a laser cavity mode selection element 3, and a laser mode detection module 4.

[0051] The laser gain module 1 is used to achieve a stable laser gain;

[0052] The cavity mirror element 2 of the resonant cavity is selected with a suitable radius of curvature and output coupling rate to cooperate with the laser gain module to achieve efficient laser output;

[0053] The laser cavity mode selection element 3 selects the transverse mode within the laser resonant cavity in two directions, so that HG is achieved in one direction. 0,0 Basic transverse mode output, HG output in the other direction 0,n Transverse mode output;

[0054] The laser mode detection module 4 is used to observe the envelope of the output light spot, and adjusts the angle of the cavity mirror element 2 according to the observation results to introduce the detuning of the resonant cavity. At the same time, it adjusts the position of the laser mode selection element 3 until a high-purity Hermitian-Gaussian laser mode appears.

[0055] The cavity mirror element 2 and the laser cavity mode selection element 3 of the resonant cavity realize differentiated control of the loss of cavity modes of different orders, thereby ensuring the high purity output of one-dimensional high-order Hermit-Gaussian laser beams of different orders.

[0056] This embodiment of the device optimizes the design of the laser resonator and, by combining the control of the intracavity mode selection element and the angle detuning, differentially modulates the intracavity mode loss of different orders, generating high-purity one-dimensional Hermitian-Gaussian laser beams of different orders. This method achieves high-purity one-dimensional high-order Hermitian-Gaussian laser output, and further, hollow spot output can be achieved using mode conversion methods, showing broad application prospects in quantum optics, optical imaging, laser material processing, and optical measurement.

[0057] The above devices are described below:

[0058] First is the laser gain module 1, which includes the pump laser and coupling submodule 1-a, the gain medium 1-b, and the thermal management module 1-c;

[0059] The pump laser and coupling submodule 1-a is used to pump the gain medium 1-b and achieve long-term stable laser output under the action of the thermal management module 1-c, wherein the aspect ratio of the gain medium 1-b is not less than 1:5.

[0060] In this module, the pump laser and coupling submodule 1-a consists of an 808nm side-emitting semiconductor laser array operating in quasi-continuous mode and a trapezoidal waveguide. The gain medium and thermal management module 1-b is an Nd:YAG trapezoidal slab laser medium with a doping concentration of 0.6at%, dimensions of 139mm×45mm×4mm, 56° chamfers on both sides, and a 1064nm high-transparency film coated on the beveled surface, and a water-cooling module.

[0061] Next is the cavity mirror element 2 of the resonant cavity, which includes the rear cavity mirror 2-a and the output coupling mirror 2-b;

[0062] The distance between the cavity mirrors 2 of the resonant cavity and the radius of curvature of the rear cavity mirror 2-a are determined by the beam transmission matrix. The output coupling mirror 2-b can select different output coupling rates according to the gain characteristics of the selected laser to achieve efficient laser output.

[0063] The distance between the cavity mirrors 2 in the resonant cavity and the radius of curvature of the rear cavity mirror 2-a are determined by the beam transmission matrix. The rear cavity mirror 2-a is a plano-concave spherical reflector with a radius of curvature R of 1600 and coated with a 1064nm high-reflectivity film. The output coupling mirror 2-b is a planar output coupling mirror with a transmittance of 5%. The distance between the rear cavity mirror 2-a and the end face of the slab laser medium is 90mm; the distance between the other end face of the slab laser medium and the output coupling mirror 2-b is 542mm.

[0064] Next is the laser mode selection element 3, which is a strip mode limiting aperture with adjustable size and position;

[0065] The laser mode selection element 3 limits the mode along the width and height directions of the gain medium, and adjusts the size of the mode limiting aperture to control the mode volume of the output mode.

[0066] The size of the laser mode selection element is calculated based on the fundamental mode size at the aperture calculated from the self-reproducible beam transmission matrix and the theoretical mode size ratio of the required higher-order Hermitian-Gaussian mode to the fundamental mode. This theoretical mode size ratio is obtained through the normalized intensity distribution of the Hermitian-Gaussian mode.

[0067] The theoretical normalized intensity distribution of the Hermit-Gaussian model is determined by the following formula:

[0068]

[0069] in, The theoretical complex amplitude distribution of a Hermitian-Gaussian laser:

[0070]

[0071] Among them, C mn : normalization coefficient; k: wavenumber; z R: is the Rayleigh length of the modulus; z: is the propagation distance of the beam starting from z=0; w(z): is the beam waist at plane z; H m (x) and H n (x): Hermitian polynomials of order m and n, respectively;

[0072] The laser mode selection element has an aperture light-passing size L. x L y Adjustable, but must ensure the basic transverse mode output in one direction, such as the x-direction, i.e., HG. 0,0 The mode, while the other direction is through the aperture L. y Select the modulus volume, and the corresponding dimension is the HG of the output. 0,n The order of the module n and the size range are as follows:

[0073]

[0074] Among them, the aspect ratio L of the aperture is x :L y In principle, the ratio can be changed from 1:1 to 1:20, α x =1.2~1.5, α y =1.1~1.5; β n : is the theoretical mode size ratio of the higher-order Hermitian-Gaussian mode to the fundamental mode; w0: is the fundamental mode size at the aperture calculated from the self-reproducible beam transmission matrix;

[0075] In this embodiment, the laser mode selection element 3 is an aperture with a dimension of 2.7 mm along the width direction of the slab and a dimension of 1.5 mm along the thickness direction of the slab; the distance between the mode limiting aperture and the output coupling mirror 2-b is 5 mm.

[0076] Finally, we introduce the laser mode detection module 4, which includes a laser attenuation element 4-a and an element 4-b for observing the light spot. The observation element 4-b can be a camera, photographic paper, or photosensitive film.

[0077] This module is used to observe the envelope and contrast of the output light spot. Laser attenuation element 4-a is an attenuation plate group, and element 4-b used to observe the light spot is a CCD camera.

[0078] In some alternative embodiments of this application, the gain medium of the laser gain module 1 is a solid gain medium such as a crystal, ceramic or glass doped with excitation ions, or a liquid gain medium a fluid doped with Nd, or a gaseous gain medium such as CO2.

[0079] In some optional embodiments of this application, there are multiple laser gain modules 1; the multiple laser gain modules 1 are arranged in series.

[0080] In some alternative embodiments of this application, the device further includes a polarizing mirror or uses Brewster angle incident light to achieve laser polarization output.

[0081] In some optional embodiments of this application, a Q-switching or mode-locking device is also added to the laser cavity mode selection element 3 to achieve short-pulse HG. 0,n Laser beam output.

[0082] It should be noted that the Hermite-Gaussian laser beam generating device provided in this application embodiment can be executed by the Hermite-Gaussian laser beam generating method or by the control module in the Hermite-Gaussian laser beam generating device for executing the Hermite-Gaussian laser beam generating method.

[0083] like Figures 4-6 As shown, by using a slab laser and designing the mode limiting aperture size and adjusting the pitch angle of the output coupling mirror, a high-purity one-dimensional high-order Hermitian-Gaussian laser can be generated.

[0084] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatuses in the embodiments of this application is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0085] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A Hermitian-Gaussian laser beam generating device, characterized in that, include: Laser gain module (1), cavity mirror element of resonant cavity (2), laser cavity mode selection element (3) and laser mode detection module (4). The laser gain module (1) is used to achieve a stable laser gain; The cavity mirror element (2) of the resonant cavity is selected with a suitable radius of curvature and output coupling rate to cooperate with the laser gain module (1) to achieve efficient laser output; The laser cavity mode selection element (3) selects the transverse mode in the laser resonant cavity in two directions to achieve HG in one direction. 0,0 Basic transverse mode output, HG output in the other direction 0,n Transverse mode output; The laser mode detection module (4) is used to observe the envelope of the output spot and adjust the angle of the cavity mirror according to the observation results to introduce the detuning of the resonant cavity. At the same time, the position of the laser mode selection element (3) is adjusted until a high-purity Hermit-Gaussian laser mode appears. The cavity mirror element (2) and the laser cavity mode selection element (3) of the resonant cavity realize differentiated control of the loss of cavity modes of different orders, thereby ensuring the high purity output of one-dimensional high-order Hermit-Gaussian laser beams of different orders. The laser gain module (1) includes a pump laser and coupling submodule (1-a), a gain medium (1-b), and a thermal management module (1-c). The pump laser and coupling submodule (1-a) is used to pump the gain medium (1-b) and achieve long-term stable laser output under the action of the thermal management module (1-c). The aspect ratio of the gain medium (1-b) is not less than 1:

5. The gain medium (1-b) adopts an asymmetric transverse cross-section design and achieves fundamental mode output in one direction through self-limiting mode action. The cavity mirror element (2) of the resonant cavity includes a rear cavity mirror (2-a) and an output coupling mirror (2-b); the distance between the cavity mirrors of the resonant cavity and the radius of curvature of the rear cavity mirror (2-a) are determined by the beam transmission matrix, and the output coupling mirror (2-b) can select different output coupling rates according to the gain characteristics of the selected laser to achieve efficient laser output; The laser mode selection element (3) is a strip-shaped mode limiting aperture with adjustable size and position; the laser mode selection element (3) limits the mode along the width and height directions of the gain medium (1-b), and the size of the mode limiting aperture is adjusted so that the mode volume of the output mode can be controlled; The size of the laser mode selection element (3) is calculated based on the fundamental mode size at the aperture calculated from the self-reproducible beam transmission matrix and the theoretical mode size ratio of the required higher-order Hermitian-Gaussian mode to the fundamental mode. This theoretical mode size ratio is obtained through the normalized intensity distribution of the Hermitian-Gaussian mode. The theoretical normalized intensity distribution of the Hermit-Gaussian model is determined by the following formula: in, The theoretical complex amplitude distribution of a Hermitian-Gaussian laser: in, C mn : represents the normalization coefficient; k : represents the wave number; z R : is the Rayleigh length of the modulus; z : For the beam from z =0 is the propagation distance starting from point 0; w ( z ): for plane z The waistband at the point; H m ( x )and H n ( x ): respectively m, n Hermitian polynomials of order 1; The size L of the aperture of the laser mode selection element (3) x L y Adjustable, but must ensure the basic transverse mode output in one direction, such as the x-direction, i.e., HG. 0,0 The mode, while the other direction is through the aperture L. y Select the modulus volume, and the corresponding dimension is the HG of the output. 0,n The modulus order n, and the size range are as follows: Among them, the aspect ratio L of the aperture is x :L y It can be changed from 1:1 to 1:20, which is equivalent to 1.2~1.5, or 1.1~1.

5. : The theoretical modulus size ratio between the higher-order Hermitian-Gaussian mode and the fundamental mode; : The fundamental mode size at the aperture calculated based on the self-reproducible beam transmission matrix; The laser mode detection module (4) includes a laser attenuation element and an element for observing the light spot. The observation element is a camera, photographic paper, or photosensitive probe. The pump power of the laser gain module (1), the pitch and sway angle of the output coupling mirror (2-b) and the position of the laser mode selection element (3) can all be adjusted so that the resonant cavity emits light near the threshold. The laser mode detection module (4) is used to observe the envelope and contrast of the output spot, and adjust the pitch angle of the output coupling mirror (2-b) and the position of the laser mode selection element (3) according to the observation results until the highest-order Hermit-Gaussian mode limited by the high-purity laser mode selection element (3) appears. The adjustment of the pitch angle of the output coupling mirror (2-b) introduces the detuning of the resonant cavity, and differentiates the intracavity mode loss of different orders to output high-purity one-dimensional high-order Hermit-Gaussian laser beams of different orders. The high purity refers to the correlation coefficient of a one-dimensional high-order Hermitian-Gaussian laser beam obtained by the device with the theoretical normalized intensity distribution of the corresponding order Hermitian-Gaussian laser, which is not less than 0.

8. The correlation coefficient is determined by the following formula: in, : The intensity of light at each position after the one-dimensional higher-order Hermitian-Gaussian laser beam obtained by the device is discretized into N positions along the higher-order mode direction; : The theoretical normalized light intensity at each position after the corresponding order Hermitian-Gaussian laser is discretized into N positions along the higher-order mode direction.

2. The Hermitian-Gaussian laser beam generating device according to claim 1, characterized in that, The gain medium (1-b) of the laser gain module (1) is a solid gain medium such as a crystal, ceramic or glass doped with excitation ions, or a liquid gain medium (1-b) a fluid doped with Nd, or a gaseous gain medium (1-b) such as CO2.

3. The Hermitian-Gaussian laser beam generating device according to claim 1, characterized in that, The laser gain module (1) is multiple; The laser gain modules (1) are arranged in series.

4. The Hermitian-Gaussian laser beam generating device according to claim 1, characterized in that, The Hermite-Gaussian laser beam generating device also includes a polarizing mirror or uses Brewster angle incident light to achieve laser polarization output.

5. The Hermitian-Gaussian laser beam generating device according to claim 1, characterized in that, The laser cavity mode selection element (3) also incorporates a Q-switching or mode-locking device to achieve short-pulse HG. 0,n Laser beam output.

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