Method for testing properties of composite laser ceramics

Abstract

The application relates to a performance test method of a composite structure laser ceramic, which comprises physical and chemical property tests and laser output characteristic tests of the composite structure laser ceramic; the physical and chemical property tests at least include ceramic density tests, microstructure tests, transmittance tests, stress tests and ion doping tests; and the laser output characteristic tests at least include pump light absorption characteristic tests, thermal lens focal length tests, end face temperature tests and laser output power tests. Through the tests on the internal structure characteristics and the laser output characteristics of the composite structure laser ceramic, the application realizes the evaluation of the comprehensive performance of the laser ceramic and provides quick optimization feedback for the design and preparation of the composite structure laser ceramic.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of performance testing of composite structure laser ceramics, and particularly relates to a performance testing method of composite structure laser ceramics. BACKGROUND

[0002] With the maturity of ground equipment, many applications will expand to the astronomical and space fields, such as quantum communication, space gravitational wave detection, deep space communication, etc., which puts forward higher requirements on the performance of high-power single-frequency continuous lasers. In addition to the requirements of high beam quality, high power and narrow linewidth output, the laser is also required to have long service life, low energy consumption, radiation resistance and other characteristics. When the traditional uniformly doped Nd:YAG and Nd:YVO4 crystals are used as gain media, under high-power pumping, the early absorption of the doped ions at the incident end of the crystal to the pump laser leads to the weak absorption of the pump laser at the rear end of the crystal, thereby causing the uneven thermal distribution in the crystal along the laser propagation direction. The temperature gradient caused by the uneven thermal distribution produces a serious thermal lens effect in the crystal, which greatly reduces the light output efficiency, beam quality and output power stability of the laser.

[0003] Although laser ceramics as a laser gain medium has a promising prospect, its preparation process is full of challenges. As early as 1995, Dr. Ikesue of Japan realized the preparation of low scattering loss Nd:YAG laser ceramics through vacuum reaction sintering technology, and first realized laser output, which aroused the widespread attention of scholars in the relevant field worldwide. In 2001, Konoshima Company of Japan successfully realized the small batch preparation of YAG-based laser ceramics, and its scattering loss reached 0.001 cm -1The horizontal, practical, and productized process accelerated. In 2002, under the support of the U.S. Air Force project, VLOC systematically evaluated the spectrum, mechanics, thermal, optical uniformity, and scattering loss of more than 1000 pieces of YAG-based laser ceramics purchased from Konoshima. The research results showed that the optical quality of small-size YAG laser ceramics reached the level of corresponding single crystals, and large-size YAG laser ceramics were even better than single crystals in terms of doping concentration uniformity and optical uniformity. Laser ceramics began to be applied in the field of high-energy lasers in the United States. Since 2009, based on large-size and high-quality Nd:YAG / Yb:YAG laser ceramic slabs provided by Japanese Konoshima Company, the U.S. companies Daystar and Novotech have achieved 100kW and 105kW laser output, respectively, fully demonstrating the application potential of laser ceramics in high-energy solid-state lasers. The research results show that by simply increasing the number of slabs and increasing the aperture of the gain medium, the output power of the laser can be linearly increased, which provides a new solution for the technical approach of using large-aperture gain medium and single resonator to achieve high-power laser scaling. One of the core technologies is high-doping concentration uniformity and large-size laser ceramic gain medium. In 2016, the DiPOLE-100 laser developed by the Rutherford Appleton Laboratory in the United Kingdom operated continuously and stably for more than 1h at the index of 100J and 10Hz, becoming a new milestone in the history of solid-state lasers. The laser head of the laser uses 6 pieces of Cr4+:YAG-clad Yb:YAG laser ceramics (120mm×120mm×8.5mm, clad 10mm wide) ordered from Japanese Konoshima Company, fully demonstrating the advantages of laser ceramics in gain medium design flexibility, large size, and high optical uniformity.

[0004] In 2018, LLNL made new progress in the design and preparation of laser ceramics. They started with spray pyrolysis YAG powder, and through slurry direct writing technology, they publicly reported the first additive formed Nd:YAG laser ceramic in the world, achieved high interface control precision, and prepared a simple structure of composite structure, and obtained a peak power of 2.27kW laser output. This explores a new technical approach for people to start from the performance requirements of the laser, design the structure of the laser gain medium, and realize controllable preparation.

[0005] Since 2001, China has carried out related research on laser ceramics. In 2006, the Shanghai Institute of Ceramics of the Chinese Academy of Sciences first achieved laser output, and in 2013, it achieved high-efficiency laser output with a power of 4350W. The scattering loss of the laser ceramic slab used was at the level of 0.002-0.003cm-1. In October 2016, the Shanghai Institute of Ceramics of the Chinese Academy of Sciences prepared a gradient-doped YAG / Nd:YAG / YAG composite structure laser ceramic slab (five-section type) with a size of 150.2mm×30mm×2.5mm, whose scattering loss was less than 0.001cm-1, and it achieved a maximum laser output of 7088W from a single slab, fully demonstrating the advantages of gradient-doped composite structure laser ceramics in power extraction. In 2021, Wei Mengen et al. of the Hefei Institute of Material Sciences of the Chinese Academy of Sciences used a 0.39-0.80at.% gradient-doped Nd:YAG rod crystal as a gain medium and obtained a 24.2W, 2kHz 1064nm laser output, confirming that the use of gradient-doped crystals can significantly homogenize the thermal distribution of the pump light along the propagation direction inside the rod crystal, greatly reducing the temperature gradient and thermal lens effect inside the crystal, and significantly improving the laser output power and light extraction efficiency.

[0006] For multi-section gradient-doped neodymium ion laser gain media, composite structure laser ceramics have more application potential. Not only is the processing period short and the processing cost low, but through fine design and preparation, the internal temperature distribution of the gain medium can be significantly homogenized, the light extraction efficiency and output power can be improved, and the parasitic oscillation problem that easily occurs in all-solid-state amplifiers can be suppressed, reducing the intensity noise of the laser. The characteristics of flexible doping and low-cost preparation of laser ceramics are more conducive to the trial study of more suitable Cr ion doping concentrations and the improvement of the spatial environmental adaptability of the laser.

[0007] The composite structure laser ceramic has the characteristics of flexible design and short preparation period, but due to the strong interface effect (stress, gain ion doping uniformity will deteriorate to a certain extent) that the composite structure is bound to have, although the interface effect can be controlled at a low level through process control, different composite structure design schemes will have corresponding changes in process parameters. Therefore, it is of great significance to develop test methods for the characteristics of composite structure laser ceramics and for the laser output characteristics of ceramics.

[0008] The granted invention patent "Measuring device and measuring method and application for measuring weak anisotropy in large-size isotropic laser medium (ZL 202111619346.6)" mainly builds a laser device, measures the power, polarization and other characteristics of the output laser, and solves the problem of measuring weak anisotropy in isotropic laser medium caused by various factors. "Multi-layer YAG-Tm:YAG-YAG-Ho:YAG-YAG composite laser ceramic and its preparation method and application (ZL 201410478024.8)" proposes a preparation method of multi-type gain ion doped composite structure laser ceramic, and also mentions the measurement of linear transmittance and fluorescence characteristics of the sample, but does not involve the comprehensive performance test of the ceramic sample. "Composite laser ceramic and its preparation method (ZL 201410648103.9)" mainly proposes a method for processing and preparing a composite structure laser ceramic composed of a laminated upper and lower chromium-doped lutetium aluminum garnet (Cr:LuAG) ceramic and a laminated upper and lower neodymium-doped lutetium aluminum garnet (Nd:LuAG) ceramic, and the edges of which are wrapped with a samarium-doped lutetium aluminum garnet (Sm:LuAG) ceramic. The main purpose is to achieve high pump coupling efficiency and fluorescence lifetime. The patent does not involve performance testing of the composite structure laser ceramic. The accepted invention patent "Design method of gradient-doped composite structure laser ceramic (202310193801.3)" mainly aims at the serious non-uniformity of temperature difference and stress difference in the crystal caused by the e-exponential decay characteristics of pump light along the transmission direction and the thermal gradient characteristics along the vertical light transmission direction of traditional uniform doped gain medium, and proposes a design method of gradient-doped composite structure laser ceramic. The performance test of the prepared composite structure laser ceramic is not involved.

[0009] Therefore, there is an urgent need to design a method for testing the performance of a composite structure laser ceramic. SUMMARY

[0010] To solve the technical problems existing in the prior art, the purpose of the present application is to provide a performance test method for a composite structure laser ceramic, to realize the performance test of the composite structure laser ceramic, and to provide strong support for the preparation of high-performance composite structure laser ceramic.

[0011] To achieve the above-mentioned purpose of the application, the present application provides a performance test method for a composite structure laser ceramic, which comprises physical and chemical property test and laser output characteristic test of the composite structure laser ceramic.

[0012] The physical and chemical property test at least includes ceramic density test, microstructure test, transmittance test, stress test and ion doping test.

[0013] The laser output characteristic test at least includes pump light absorption characteristic test, thermal lens focal length test, end face temperature test and laser output power test.

[0014] According to one of the technical solutions of the present application, the pump light absorption characteristic test is completed by building a pump laser absorption test light path based on the composite structure laser ceramic, and the specific process is as follows:

[0015] By measuring the pump light absorption efficiency under the conditions of having and not having laser output and not having laser output, and comparing with the theoretical absorption efficiency of the pump light, the pump light absorption characteristic of the composite structure laser ceramic is evaluated.

[0016] The pump laser is irradiated on different positions of the composite structure laser ceramic, and the pump light absorption characteristic of different regions of the composite structure laser ceramic is measured to quantitatively evaluate the pump light absorption uniformity of the composite structure laser ceramic.

[0017] According to one of the technical solutions of the present application, the pump light absorption efficiency is calculated by the following formula:

[0018]

[0019] Wherein, P1 is the coupled pump light power, P1 is the residual pump light power, a is the absorption coefficient of the composite structure laser ceramic, and l is the length of the composite structure laser ceramic.

[0020] According to one of the technical solutions of the present application, the thermal lens focal length of the composite structure laser ceramic under different power conditions is measured and compared with the theoretical calculation value to evaluate the improvement of the thermal effect of the composite structure laser ceramic.

[0021] Wherein, the theoretical calculation value of the focal length of the thermal lens is f th-c The calculation is carried out by the following formula:

[0022]

[0023] Wherein, k c is the thermal conductivity, ω p is the spot radius of the pump light, dn / dt is the thermal-optical coefficient, a is the absorption coefficient of the laser medium, l is the length of the medium, P in is the pump laser power acting on the composite structure laser ceramic, η abd is the absorption rate of the medium to the pump laser, and η b is the conversion rate of the absorbed energy into heat.

[0024] According to one of the technical solutions of the present application, the thermal lens focal length is measured by constructing a Mach-Zehnder interferometer to measure the movement of interference fringes before and after the pump laser is loaded, to judge the optical path difference before and after the pump light is loaded, and the specific formula is as follows:

[0025]

[0026] wherein, f th-t is the measured value of the focal length of the thermal lens, is the change of the interference fringes, is the wavelength of the probe laser of the interferometer, r0 is the radius of the end face of the composite structure laser ceramic, and n0 is the refractive index of the composite structure laser ceramic.

[0027] According to one of the technical solutions of the present application, the composite structure laser ceramic is used to build a laser, and laser output is realized.

[0028] According to one of the technical solutions of the present application, the laser output power test is used to comprehensively evaluate the performance of the composite structure laser ceramic.

[0029] According to one of the technical solutions of the present application, the process of the ceramic density test includes: by measuring the actual density of the composite structure laser ceramic, and comparing with the theoretical density value, preliminarily evaluating whether there are a large number of bubbles inside the composite structure laser ceramic sample.

[0030] The process of the microstructure test includes: by observing the grains, grain boundaries and miscellaneous items inside the composite structure laser ceramic, qualitatively evaluating whether the interface characteristics of the composite structure laser ceramic meet the requirements of laser operation.

[0031] The process of the transmittance test includes: by measuring the actual transmittance of the composite structure laser ceramic, quantitatively evaluating the uniformity and loss of the composite structure laser ceramic.

[0032] The process of the stress test includes: by measuring the stress condition of the composite structure laser ceramic, observing the stress condition of the corners and interfaces of the composite structure laser ceramic sample, avoiding the larger stress abnormal area of the composite structure laser ceramic, and ensuring that the composite structure laser ceramic used for laser output has a relatively uniform stress characteristic.

[0033] The process of the ion doping test includes: by testing the gain ion doping concentration of the composite structure laser ceramic sample, preliminarily evaluating the pump light absorption and gain condition of the composite structure laser ceramic.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] The application provides a performance testing method of composite structure laser ceramic, which can provide strong support for preparation of high-performance composite structure laser ceramic by testing the comprehensive performance of the composite structure ceramic microstructure, doping uniformity, pump light absorption characteristics, pump light absorption uniformity and other characteristics related to the internal structure of the laser ceramic and the laser output characteristics.

[0036] By establishing a complete composite structure laser ceramic testing method, the performance of the laser gain medium of the composite structure laser ceramic can be effectively evaluated, thereby providing an effective testing method for flexible design, low-cost preparation and rapid application of high-performance laser of the composite structure laser ceramic. BRIEF DESCRIPTION OF DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of these drawings.

[0038] Figure 1 A schematic diagram of a composite structure laser ceramic performance testing flowchart according to one embodiment of the present application is shown;

[0039] Figure 2 A schematic diagram of a composite structure laser ceramic pump light absorption characteristic testing device according to one embodiment of the present application is shown;

[0040] Figure 3 A schematic diagram of a composite structure laser ceramic thermal lens focal length testing device according to one embodiment of the present application is shown;

[0041] Figure 4 A schematic diagram of a composite structure laser ceramic laser output and temperature characteristic testing device according to one embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0043] As Figures 1 to 4 shown, the performance test method of the composite structure laser ceramic of the present application includes the physical and chemical property test and the laser output characteristic test of the composite structure laser ceramic.

[0044] The physical and chemical property test at least includes: ceramic density test 101, microstructure test 102, transmittance test 103, stress test 104, ion doping test 105.

[0045] The ceramic density test mainly measures the actual density of the composite structure laser ceramic, and compares it with the theoretical density value, to preliminarily evaluate whether there are a large number of bubbles in the composite structure laser ceramic sample.

[0046] The microstructure test mainly observes the grain, grain boundary, miscellaneous items and the like in the composite structure laser ceramic, to qualitatively evaluate whether the interface characteristics of the composite structure laser ceramic meet the requirements of laser operation.

[0047] The transmittance test mainly measures the actual transmittance of the composite structure laser ceramic, to quantitatively evaluate the uniformity and loss of the composite structure laser ceramic.

[0048] The stress test mainly measures the stress of the composite structure laser ceramic, and focuses on observing the stress of the sample corners and interface of the composite structure laser ceramic, to avoid the larger stress abnormal area of the composite structure laser ceramic, and to ensure that the composite structure laser ceramic used for laser output has a relatively uniform stress characteristic.

[0049] The ion doping test mainly tests the gain ion doping concentration of the composite structure laser ceramic sample, to preliminarily evaluate the pump light absorption and gain of the composite structure laser ceramic.

[0050] The laser output characteristic test at least includes: pump light absorption characteristic test 106, thermal lens focal length test 107, end face temperature test 108, laser output power test 109.

[0051] The pump light absorption characteristic test mainly sets up a pump laser absorption test optical path based on the composite structure laser ceramic, as shown in the accompanying drawings, Figure 2 Figure 2 ​The application discloses a testing device for the light absorption characteristics of a composite structure laser ceramic pumped by a laser, which comprises a pump light source 201, a scanning device 202, a shaping block 203, an input cavity mirror 204, the composite structure laser ceramic 205, an output cavity mirror 206, a light filter 207 and a power meter 208, and can test the light absorption characteristics of the composite structure laser ceramic pumped by the laser in three modes. In the first mode, the light absorption characteristics of the composite structure laser ceramic pumped by the laser are tested in a laser output mode, the laser resonant cavity is adjusted to stably operate and the output power reaches the maximum value, the output laser is filtered by the light filter 207, the residual pump laser power is measured by the power meter and compared with the total pump power acting on the composite structure laser ceramic, and the absorption efficiency of the composite structure laser ceramic is obtained. In the second mode, the light absorption characteristics of the composite structure laser ceramic pumped by the laser are tested in a laser output mode, the output cavity mirror 206 and the light filter 207 are removed on the basis of the first mode, the residual pump laser power is measured by the power meter and compared with the total pump power acting on the composite structure laser ceramic, and the absorption efficiency of the composite structure laser ceramic is obtained. In the third mode, the light absorption characteristics of different regions of the composite structure laser ceramic are tested by changing the position of the pump laser on the composite structure laser ceramic by the scanning device 202 on the basis of the second mode.

[0052] In the first mode and the second mode, the pump light absorption efficiency under the conditions of laser output and no laser output is measured respectively, and compared with the theoretical absorption efficiency of the pump light, so that the pump light absorption characteristics of the composite structure laser ceramic are evaluated.

[0053] Further, in the third mode, the pump laser is irradiated on different positions of the composite structure laser ceramic, the pump light absorption characteristics of different regions of the composite structure laser ceramic are measured, and the pump light absorption uniformity of the composite structure laser ceramic is quantitatively evaluated.

[0054] The pump light absorption efficiency is calculated by the following formula:

[0055]

[0056] Wherein, P1 is the coupled pump light power, P1 is the residual pump light power, a is the absorption coefficient of the composite structure laser ceramic, and l is the length of the composite structure laser ceramic.

[0057] The thermal lens focal length test mainly measures the thermal lens focal length of the composite structure laser ceramic under different power conditions, and compares the thermal lens focal length with the theoretical calculation value, so that the thermal effect improvement of the composite structure laser ceramic is evaluated, the theoretical calculation value is shown in formula (2), and the testing device is shown in FIG. 2. Figure 3 Figure 3 ​The laser ceramic thermal lens focal length testing device of the composite structure is shown, comprising: a probe laser source 301, a probe light shaping module 302, a first mirror 304, a composite structure laser ceramic 305, a beam combiner 306, a second mirror 307, an optical lens 308, a shaping module 309, a pump light shaping module 310 and a pump laser source 311.

[0058] Wherein, the probe laser source 301, the probe light shaping module 302, the first mirror 304, the composite structure laser ceramic 305, the beam combiner 306, the second mirror 307, the optical lens 308 and the shaping module 309 form a Mach-Zehnder interferometer containing the composite structure laser ceramic, the pump light shaping module 310 and the pump laser source 311 together realize the coupling of the pump laser into the composite structure laser ceramic, the interference fringe change situation under the condition of with or without pump light is collected through the optical lens 308 and the shaping module 309, the optical path difference change situation is calculated and obtained, and the thermal lens focal length of the composite structure laser ceramic under the action of different pump powers is calculated and obtained.

[0059] The thermal lens focal length is measured by constructing a Mach-Zehnder interferometer to measure the interference fringe movement before and after the pump laser is loaded, so as to judge the optical path difference before and after the pump light is loaded, so as to realize the measurement of the thermal lens focal length.

[0060] Wherein, the theoretical calculation value of the focal length of the thermal lens is f th-c The calculation is carried out through the following formula:

[0061]

[0062] Wherein, k c is the thermal conductivity, ω p is the spot radius of the pump light, dn / dt is the thermal-optic coefficient, α is the absorption coefficient of the laser medium, l is the length of the medium, P in is the pump laser power acting on the composite structure laser ceramic, η abs is the absorption rate of the medium to the pump laser, η b is the conversion rate of the absorbed energy into heat.

[0063] The measured value of the focal length of the thermal lens is f th-c The calculation is carried out through the following formula:

[0064]

[0065] Wherein, f th-t is the measured value of the focal length of the thermal lens, Δm is the interference fringe change amount, λ is the probe laser wavelength of the interferometer, r0 is the end face radius of the composite structure laser ceramic, and n0 is the refractive index of the composite structure laser ceramic.

[0066] The composite structure laser ceramic is attached Figure 4The laser output and temperature characteristic testing device of the composite structure laser ceramic is shown, which comprises a pump laser source 401, a shaping module 402, an input cavity mirror 403, a temperature detection module 404, a composite structure laser ceramic 405, an output cavity mirror 406, a filter device 407 and a power meter 408.

[0067] The temperature detection module 404 is a composite structure laser ceramic end face temperature testing device.

[0068] The laser is built by using the composite structure laser ceramic, and laser output is realized, the temperature of the front and rear end faces of the composite structure laser ceramic is measured under different pump powers, and the improvement of the temperature distribution gradient of the composite structure laser ceramic is evaluated, and the end face temperature test is completed.

[0069] The laser output power test is used for comprehensive evaluation of the performance of the composite structure laser ceramic, the laser is built by using the composite structure laser ceramic, and laser output is realized, and the laser output power under different pump powers is measured.

[0070] The performance test method of the composite structure laser ceramic comprises physical and chemical property testing and laser output characteristic testing of the composite structure laser ceramic, the physical and chemical property testing at least comprises ceramic density testing, microstructure testing, transmittance testing, stress testing and ion doping testing, and the laser output characteristic testing at least comprises pump light absorption characteristic testing, thermal lens focal length testing, end face temperature testing and laser output power testing.

[0071] It should be noted that the above is the preferred embodiment of the present application, and it should be pointed out that although the preferred embodiment of the present application has been described, for those skilled in the art, once the basic creative concept of the present application is known, several improvements and refinements can be made without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application. Therefore, the appended claims are intended to be interpreted as including the preferred embodiment and all modifications and modifications falling within the scope of the embodiments of the present application.

Claims

1. A method of testing the performance of a composite structure laser ceramic, characterized by, The physical and chemical property test and the laser output characteristic test of the composite structure laser ceramic are included; The physical and chemical property test at least includes: ceramic density test, microstructure test, transmittance test, stress test, ion doping test; The laser output characteristic test at least includes: pump light absorption characteristic test, thermal lens focal length test, end face temperature test, laser output power test; The thermal effect improvement of the composite structure laser ceramic is evaluated by comparing the thermal lens focal length of the composite structure laser ceramic under different power conditions with the theoretical calculation value; wherein the theoretical calculated value of the focal length of the thermal lens f th-c The calculation is made by the following equation: wherein k c is the thermal conductivity, ω p is the spot radius of the pump light, dn / dt is the thermo-optic coefficient, α is the absorption coefficient of the laser medium, l is the length of the medium, P in is the pump laser power acting on the composite laser ceramic, η abs is the absorption of the medium to the pump laser, η b is the conversion rate of the absorbed energy into heat.

2. The method of claim 1, wherein, The pump light absorption characteristic test is completed by building a pump laser absorption test light path based on the composite structure laser ceramic, and the specific process is as follows: The pump light absorption characteristics of the composite structure laser ceramic are quantitatively evaluated by measuring the pump light absorption efficiency under the conditions of having laser output and not having laser output, and comparing with the theoretical absorption efficiency of the pump light. The pump light absorption efficiency is calculated by the following formula:

3. The method of claim 2, wherein, Wherein, P1 is the coupled pump light power, P2 is the residual pump light power, a is the absorption coefficient of the composite structure laser ceramic, and l is the length of the composite structure laser ceramic. The thermal lens focal length is measured by building a Mach-Zehnder interferometer to measure the movement of interference fringes before and after the pump laser is loaded, to judge the optical path difference before and after the pump light is loaded, and the specific formula is as follows:

4. The method of claim 1, wherein, The laser is built by using the composite structure laser ceramic, and the laser output is realized, the temperature of the front and rear end faces of the composite structure laser ceramic is measured under different pump power conditions, to evaluate the improvement of the temperature distribution gradient of the composite structure laser ceramic, and the end face temperature test is completed. wherein f th-t is a measured value of the focal length of the thermal lens, Δm is the amount of change of the interference fringes, λ is the wavelength of the probe laser of the interferometer, r0 is the radius of the end face of the composite structure laser ceramic, and n0 is the refractive index of the composite structure laser ceramic.

5. The method of claim 1, wherein, The laser output power test is used to comprehensively evaluate the performance of the composite structure laser ceramic, the laser is built by using the composite structure laser ceramic, and the laser output is realized, and the laser output power under different pump power conditions is measured.

6. The method of claim 5, wherein, The process of the ceramic density test includes: the actual density of the composite structure laser ceramic is measured, and compared with the theoretical density value, to preliminarily evaluate whether there are a large number of bubbles in the composite structure laser ceramic sample; 7. The method of claim 1, wherein, The process of the microstructure test includes: the grain, grain boundary and miscellaneous items in the composite structure laser ceramic are observed, to qualitatively evaluate whether the interface characteristics of the composite structure laser ceramic meet the requirements of laser operation; The process of the transmittance test includes: the actual transmittance of the composite structure laser ceramic is measured, to quantitatively evaluate the uniformity and loss of the composite structure laser ceramic; The process of the stress test includes: the stress of the composite structure laser ceramic is measured, and the stress of the sample corners and interfaces of the composite structure laser ceramic is observed, to avoid the larger stress abnormal area of the composite structure laser ceramic, and to ensure that the composite structure laser ceramic used for laser output has relatively uniform stress characteristics; ​ The process of the ion doping test comprises: testing the gain ion doping concentration of the composite structure laser ceramic sample, so as to preliminarily evaluate the pumping light absorption and gain of the composite structure laser ceramic.

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