Device and method for measuring thermal effect parameters of disc laser crystal

Abstract

The invention relates to the technical field of optics, in particular to a device and method for measuring heat effect parameters of a disc laser crystal, and the device comprises a first laser, a lens group, a beam splitter prism, a fixed focus lens, a filtering unit, an imaging unit, a standard plane mirror and a measuring unit. The lens group and the beam splitter prism are sequentially arranged along the light emitting path direction of the first laser, the first laser is used for emitting probe light, the probe light is subjected to beam expansion and collimation through the lens group and then is subjected to beam splitting through the beam splitter prism, and primary transmission light forms a reference light spot; after the primary reflected light is reflected by the standard plane mirror, secondary reflected light is obtained, and the measuring unit is arranged in the light path direction of the secondary reflected light; after being transmitted by the beam splitter prism of the secondary reflection mirror, the light is reflected by the disc laser crystal and returns along the original path to form a detection light spot; according to the technical scheme provided by the invention, the parameters of the thermal lens effect of the disc laser crystal in the laser to be measured can be measured, and the parameters of the hot air wedge effect can also be measured.

Description

Technical Field

[0001] The invention belongs to the field of optical technology, and in particular relates to a device and a method for measuring thermal effect parameters of a disk laser crystal. Background Art

[0002] Since the advent of the world's first ruby ​​laser, laser technology has been widely used in various fields, especially in military defense, cutting-edge science, biomedicine and industrial processing. Among the many types of lasers, solid-state lasers have the advantages of stable structure and long service life. However, the traditional solid-state laser gain working medium usually adopts a rod or slab shape. This type of laser has a serious thermal lens effect when working, which affects the performance of the output laser, especially the poor beam quality limits the application range of the laser.

[0003] The introduction of disk laser technology has effectively solved the thermal effect problem in solid lasers, allowing the output laser to maintain good beam quality. Disk laser technology is to make the laser gain medium into a thin slice with a large diameter-to-thickness ratio (i.e., the ratio of diameter to thickness) (i.e., disk laser crystal), and connect one side of it to a heat sink with good thermal conductivity, using coolant for cooling, and the other side as a reflector in the laser resonant cavity. This design can efficiently export the waste heat generated when the laser is running.

[0004] Disk lasers usually use fiber-coupled semiconductor lasers as pump sources. Due to the temperature difference between the pumping area and the non-pumping area and the uneven distribution of the light intensity in the pumping area when the pumping light acts, the internal temperature distribution of the disk laser crystal is uneven during operation, causing the disk laser crystal to deform to a certain extent. The surface temperature of the laser disk crystal is usually much higher than room temperature during operation. Under non-vacuum indoor conditions, due to the gravity of the ambient air and the heat transfer generated by the disk laser crystal, the refractive index of the air at different positions in front of the disk laser crystal is different, causing the light path to be deflected when the laser passes through the reflector of the disk laser crystal. This effect is usually called the hot air effect.

[0005] Due to the influence of the thermal effect of the disk laser crystal itself and the hot air effect, it cannot be equivalent to a plane reflector. Combining the thermal lens effect of the disk itself and the hot air effect, the disk laser crystal can be equivalent to a spherical reflector for laser design. The remaining thermal effect of the hot air effect, except for the thermal lens effect, can be equivalent to a wedge lens, that is, it can be equivalent to a hot air wedge.

[0006] Therefore, in the design of lasers, it is very important to measure the variation of thermal lens effect and hot air wedge effect with pump power. Summary of the invention

[0007] In view of this, in order to better solve the technical problems related to measuring thermal lens effect parameters and hot air wedge effect parameters, the present invention aims to provide a measuring device and method for thermal effect parameters of a disk laser crystal.

[0008] To achieve the above object, the technical solution created by the present invention is implemented as follows: A device for measuring thermal effect parameters of a disk laser crystal, the device comprising a first laser, a lens group, a beam splitter, a fixed focus lens, a filtering unit, an imaging unit, a standard plane mirror and a measuring unit; The lens group and the beam splitter prism are sequentially arranged along the light path direction of the first laser, the first laser is used to emit probe light, the probe light is expanded and collimated by the lens group, and then split by the beam splitter prism to obtain a primary transmitted light and a primary reflected light respectively; The fixed-focus lens, the filtering unit and the camera are sequentially arranged along the optical path direction of the primary transmitted light, and the standard plane mirror is arranged along the optical path direction of the primary reflected light; after the primary reflected light is reflected by the standard plane mirror, secondary reflected light is obtained, and the measuring unit is arranged along the optical path direction of the secondary reflected light; After the primary transmitted light passes through the fixed-focus lens and the filtering unit in sequence, it is imaged on the imaging unit, and the obtained imaging light spot is the reference light spot; The secondary reflected light is transmitted to the beam splitter prism, and is split by the beam splitter prism to obtain secondary transmitted light and tertiary reflected light respectively; the secondary transmitted light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; after being reflected by the disk laser crystal, the secondary transmitted light returns along the original path, and after the secondary transmitted light returns along the original path, it passes through the fixed focus lens and the filtering unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; When the pump source of the laser to be measured is working, the measurement unit is adjusted so that the detection light spot and the reference light spot meet preset conditions, and the thermal effect parameters of the disk laser crystal are determined according to the corresponding attribute values ​​of the measurement unit; the preset conditions include that the detection light spot overlaps with the reference light spot, and the diameter parameter difference between the detection light spot and the reference light spot is minimal.

[0009] Furthermore, the measuring unit includes an electrodeformation driven zoom lens, a first 45° reflector, and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light.

[0010] Furthermore, the measuring unit also includes a piezoelectric control mirror frame and a piezoelectric controller; The piezoelectric controlled mirror frame is used to mount the first 45° reflector and the second 45° reflector; The piezoelectric controller is electrically connected to the electrodeformation driven zoom lens; the piezoelectric controller is connected to the piezoelectric control mirror frame and is used to control the yaw and pitch angles of the first 45° reflector and the second 45° reflector.

[0011] Furthermore, the thermal effect parameters of the disk laser crystal include a hot air wedge angle α in the hot air wedge effect of the disk laser crystal. The calculation formula of the hot air wedge angle α is: α = 2b (V 2 -V 4 ); Among them, b is the calibration coefficient between the piezoelectric voltage value and the deflection angle of the first 45° reflector when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset conditions; V2 and V4 are the piezoelectric voltage value of the first 45° reflector and the piezoelectric voltage value of the second 45° reflector, respectively, when the pump source of the laser to be tested is working and the detection spot and the reference spot meet the preset conditions.

[0012] Furthermore, the thermal effect parameters of the disk laser crystal include the thermal focal length f in the thermal lens effect of the disk laser crystal. TD , the thermal focal length f TD The calculation formula is: f TD =a (V 1-1 -V 1-2 ) Wherein, a is the voltage and focal length f of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset condition. 变 Calibration coefficient between 1-1 is the initial voltage of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection light spot and the reference light spot meet the preset condition; V 1-2 It is the voltage of the electro-deformation driving zoom lens when the pump source of the laser to be tested works and the detection light spot and the reference light spot meet the preset condition.

[0013] Furthermore, the measuring unit comprises a zoom lens group, a first 45° reflector and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light; the zoom lens group comprises an electro-deformation driven zoom lens and a preset focus lens.

[0014] Furthermore, the measuring unit includes an electro-deformable reflector and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light.

[0015] Further, the disk laser crystal includes a disk laser crystal, and the laser to be tested includes a disk pump module; The disk pump module includes, in sequence along the light emitting direction of the pump source: A pump source, used for pumping the disk laser crystal; A collimating lens, used to collimate the pump source; The tertiary reflecting mirror and the fourth reflecting mirror are used to make the pump laser emitted by the pump source travel back and forth in the disk laser crystal for multiple times; and disk laser crystals.

[0016] Furthermore, the property value of the measurement unit includes a voltage value and a corresponding calibration coefficient.

[0017] Furthermore, the present invention also provides a method for measuring the thermal effect parameters of the above-mentioned disk laser crystal, the measuring method is implemented by the measuring device of the present invention, and the measuring method comprises the steps of: S1. Controlling the first laser to emit the probe light; S2. Adjust the reference optical path to obtain a reference light spot imaged in the imaging unit; the reference optical path is composed of the first laser, the lens group, the beam splitter prism, the fixed focus lens, the filter unit and the imaging unit in sequence; S3. The detection light path is adjusted by the measuring unit, and the path of the detection light path includes: the probe light is expanded and collimated by the lens group, and then split by the beam splitter prism to obtain a primary transmission light and a primary reflection light respectively; the primary reflection light is reflected by the standard plane mirror to obtain a secondary reflection light; the secondary reflection light is transmitted to the beam splitter prism, and split by the beam splitter prism to obtain a secondary transmission light and a tertiary reflection light respectively; the secondary transmission light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; after being reflected by the disk laser crystal, the secondary transmission light returns along the original path, and after the secondary transmission light returns along the original path, it passes through the fixed focus lens and the filter unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; S4. When the pump source of the laser to be measured is working, adjust the measuring unit so that the detection light spot and the reference light spot meet preset conditions, obtain the corresponding attribute value of the measuring unit, and determine the thermal effect parameter of the disk laser crystal.

[0018] Compared with the prior art, the invention can achieve the following beneficial effects: The present invention creates a measuring device and method for the thermal effect parameters of a disk laser crystal. By constructing a reference optical path and a detection optical path, when the pump source of the laser to be measured is working, the measuring unit of the thermal effect parameters of the disk laser crystal is adjusted so that when the detection light spot of the probe light imaged on the camera and the reference light spot meet the preset conditions, the corresponding attribute value of the measuring unit is obtained, and the thermal effect parameters of the disk laser crystal can be determined. The new measurement technology provided by the technical solution of the present application can not only measure the parameters of the thermal lens effect of the disk laser crystal in the laser to be measured, but also measure the parameters of the hot air wedge effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings: Figure 1 A schematic diagram of a device for measuring thermal effect parameters of a disk laser crystal provided by an embodiment of the present invention; Figure 2 A schematic diagram of the measurement principle of the hot air wedge angle in the hot air wedge effect of a disk laser crystal by a device for measuring the thermal effect parameters of a disk laser crystal provided by an embodiment of the present invention; Figure 3 A simplified schematic diagram of the measuring principle of the hot air wedge angle in the hot air wedge effect of a disk laser crystal by a device for measuring the thermal effect parameters of a disk laser crystal provided by an embodiment of the present invention; Figure 4 A device for measuring the thermal effect parameters of a disk laser crystal provided by an embodiment of the present invention is provided to measure the thermal focal length in the thermal lens effect of a disk laser crystal; Figure 5 A schematic diagram of the structure of a device for measuring thermal effect parameters of a disk laser crystal provided in accordance with another embodiment of the present invention.

[0020] Reference numerals: Pump source 1, collimating lens 2, fixture 3, tertiary reflector 4, fourth reflector 5, coolant 6, disk laser crystal 8, standard plane mirror 9, beam splitter prism 10, electro-deformation driven zoom lens 11, first laser 12, first lens 13, second lens 14, fixed focus lens 15, filter unit 16, camera 17, computer 18, first 45° reflector 19, second 45° reflector 20, piezoelectric controller 21, electro-deformation reflector 22; A first 45° reflector 32 for changing the yaw and pitch of the mirror frame under piezoelectric control; A second 45° reflector 42 that changes the tilt and pitch of the mirror frame under piezoelectric control; Disk laser crystal 82 when the equivalent hot air wedge acts; Electrodeformation driven zoom lens 52 for measuring thermal lens effect of disk laser crystal; Equivalent disk laser crystal 83 when thermal lens effect occurs. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

[0022] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0023] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0024] In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0025] In a specific embodiment of the present invention, a device for measuring thermal effect parameters of a disk laser crystal is provided, the measuring device comprising a first laser, a lens group, a beam splitter, a fixed focus lens, a filtering unit, an imaging unit, a standard plane mirror and a measuring unit; the lens group may comprise a first lens and a second lens, or may comprise a plurality of lenses, and the lenses to be used may be determined according to actual conditions and the spacing between the lenses may be appropriately adjusted, and at the same time, the focal length parameters of the lenses to be used and the spacing data of the related lenses may be associated with the spot radius of the collimated light required at the end; the imaging unit may be a camera; the filtering unit may comprise a bandpass filter or an attenuation plate, which is used to filter out stray light and ambient light generated during the operation of the pump source of the laser to be measured, and can ensure that the spatial stray light does not affect the measurement result, so as to ensure the accuracy of the measurement result, and appropriate light intensity attenuation ensures the safety of the measuring device; the lens group and the beam splitter are sequentially arranged along the light path direction of the first laser to emit probe light, the probe light is expanded and collimated by the lens group, and then split by the beam splitter to obtain a primary transmitted light and a primary reflected light respectively; The fixed-focus lens, the filtering unit and the camera are sequentially arranged along the optical path direction of the primary transmitted light, and the standard plane mirror is arranged along the optical path direction of the primary reflected light; after the primary reflected light is reflected by the standard plane mirror, secondary reflected light is obtained, and the measuring unit is arranged along the optical path direction of the secondary reflected light; After the primary transmitted light passes through the fixed-focus lens and the filtering unit in sequence, it is imaged on the imaging unit, and the obtained imaging light spot is the reference light spot; The secondary reflected light is transmitted to the beam splitter prism, and is split by the beam splitter prism to obtain secondary transmitted light and tertiary reflected light respectively; the secondary transmitted light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; after being reflected by the disk laser crystal, the secondary transmitted light returns along the original path, and after the secondary transmitted light returns along the original path, it passes through the fixed focus lens and the filtering unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; When the pump source of the laser to be measured is working, the measurement unit is adjusted so that the detection light spot and the reference light spot meet preset conditions, and the thermal effect parameters of the disk laser crystal are determined according to the corresponding attribute values ​​of the measurement unit; the preset conditions include that the detection light spot overlaps with the reference light spot, and the diameter parameter difference between the detection light spot and the reference light spot is minimal.

[0026] The attribute value of the measuring unit includes a voltage value and a corresponding calibration coefficient. The calibration coefficient is pre-acquired in the following manner: controlling the first laser to emit probe light; Adjust the reference light path to obtain a reference light spot where the probe light is imaged in the imaging unit; A measurement unit based on the thermal effect parameters of the disk laser crystal is used to obtain the detection light spot formed by the probe light passing through the detection light path and imaging in the imaging unit; When the pump source of the laser to be measured is not working, the measuring unit is adjusted so that the detection light spot and the reference light spot meet a preset condition, and the corresponding initial voltage of the measuring unit and the corresponding calibration coefficient are obtained.

[0027] In a specific implementation, the measuring unit includes an electrodeformation-driven zoom lens, a first 45° reflector, and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light; the measuring unit also includes a piezoelectric-controlled mirror frame and a piezoelectric controller; the piezoelectric controller is connected to the piezoelectric-controlled mirror frame, and the lenses of the first 45° reflector and the second 45° reflector are mounted on the piezoelectric-controlled mirror frame, and the piezoelectric-controlled mirror frame is driven by the piezoelectric controller to change the angles of the lenses of the first 45° reflector and the second 45° reflector; the piezoelectric-controlled mirror frame is used to mount the first 45° reflector and the second 45° reflector mirror; the piezoelectric controller is electrically connected to the electrodeformation driven zoom lens, and the piezoelectric controller is connected to the piezoelectric control mirror frame, and is used to control the yaw and pitch angles of the first 45° reflector, as well as the yaw and pitch angles of the second 45° reflector; the piezoelectric controller is used to control the voltages in the electrodeformation driven zoom lens, the first 45° reflector, and the second 45° reflector when the pump source of the laser to be tested is working, so that the detection light spot and the reference light spot meet the preset conditions, and the thermal effect parameters of the disc laser crystal are determined according to the respective voltage values ​​and the corresponding calibration coefficients.

[0028] In a specific implementation manner, the thermal effect parameter of the disk laser crystal includes a hot air wedge angle α in the hot air wedge effect of the disk laser crystal. The calculation formula of the hot air wedge angle α is: α = 2b*(V 2 -V 4 ); Among them, b is the calibration coefficient between the piezoelectric voltage value and the deflection angle of the first 45° reflector when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset conditions; V2 and V4 are the piezoelectric voltage values ​​of the first 45° reflector and the piezoelectric voltage values ​​of the second 45° reflector controlled when the pump source of the laser to be tested is working and the detection spot and the reference spot meet the preset conditions.

[0029] In a specific embodiment, the thermal effect parameters of the disk laser crystal include the thermal focal length f in the thermal lens effect of the disk laser crystal.TD , the thermal focal length f TD The calculation formula is: f TD =a (V 1-1 -V 1-2 ) Wherein, a is the voltage and focal length f of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset condition. 变 Calibration coefficient between 1-1 is the initial voltage of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection light spot and the reference light spot meet the preset condition; V 1-2 It is the voltage of the electro-deformation driving zoom lens when the pump source of the laser to be tested works and the detection light spot and the reference light spot meet the preset condition.

[0030] In a specific implementation, the device for measuring the thermal effect parameters of the disk laser crystal also includes a computer, which is connected to a piezoelectric controller, which is in turn connected to an electrodeformation-driven zoom lens and a piezoelectric mirror frame; specifically, the computer is connected to the camera, the electrodeformation-driven zoom lens, and the piezoelectric controller is connected to the piezoelectric mirror frame of the first 45° reflector and the piezoelectric mirror frame of the second 45° reflector, respectively, to obtain the reference light spot and the detection light spot of the camera, and also to automatically adjust the electrodeformation-driven zoom lens, the piezoelectric mirror frame for installing the first 45° reflector, and the property values ​​in the piezoelectric mirror frame for the second 45° reflector when the pump source of the laser to be measured is working, and determine the thermal effect parameters of the disk laser crystal according to the property value of the measurement unit corresponding to the detection light spot and the reference light spot when the pump source of the laser to be measured is adjusted.

[0031] In a specific implementation, the laser to be tested includes a disk pump module; The disk pump module includes, in sequence along the light emitting direction of the pump source: A pump source, used for pumping the disk laser crystal; A collimating lens, used to collimate the pump source; The tertiary reflecting mirror and the fourth reflecting mirror are used to make the pump laser emitted by the pump source travel back and forth in the disk laser crystal for multiple times; and disk laser crystals.

[0032] In a specific implementation manner, the disk laser further includes: A fixture to keep the disk laser crystal stable; The coolant and the disk laser crystal heat sink are used to cool the disk laser crystal and conduct waste heat.

[0033] In other embodiments, the measuring unit includes a zoom lens group, a first 45° reflector and a second 45° reflector, which are arranged in sequence along the optical path direction of the secondary reflected light; the measuring unit provided by this specific embodiment can expand the measurable range within the variable focal length range of the existing zoom lens.

[0034] In other embodiments, the measuring unit includes an electro-deformable reflector and a second 45° reflector, which are arranged in sequence along the optical path direction of the secondary reflected light, and are used to allow the probe light emitted by the first laser to pass through the lens group, be reflected by the dichroic prism, and be reflected by the standard plane mirror, and then be transmitted in the opposite direction of the original optical path, and then be transmitted through the dichroic prism again, and then be focused on the disc laser crystal of the thermal effect parameter to be measured in the laser to be measured after passing through the electro-deformable reflector and the second 45° reflector, and to allow the probe light to return along the original path, be reflected by the dichroic prism and converge and filter by the fixed-focus lens, and be imaged on the imaging unit, and the light spot is the detection light spot; and, when the pump source of the laser to be measured is working, according to adjusting the electro-deformable reflector and the second 45° reflector, when the detection light spot and the reference light spot meet the preset conditions, the thermal effect parameters of the disc laser crystal are determined by the corresponding attribute value of the measuring unit.

[0035] In a specific implementation manner, the present invention further provides a method for measuring the thermal effect parameters of the above-mentioned disk laser crystal, the measuring method is implemented by the measuring device of the present invention, and the measuring method comprises the steps of: S1. Controlling the first laser to emit the probe light; S2. Adjust the reference optical path to obtain a reference light spot imaged in the imaging unit; the reference optical path is composed of the first laser, the lens group, the beam splitter prism, the fixed focus lens, the filter unit and the imaging unit in sequence; S3. The detection light path is adjusted by the measuring unit, and the path of the detection light path includes: the probe light is expanded and collimated by the lens group, and then split by the beam splitter prism to obtain a primary transmission light and a primary reflection light respectively; the primary reflection light is reflected by the standard plane mirror to obtain a secondary reflection light; the secondary reflection light is transmitted to the beam splitter prism, and split by the beam splitter prism to obtain a secondary transmission light and a tertiary reflection light respectively; the secondary transmission light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; after being reflected by the disk laser crystal, the secondary transmission light returns along the original path, and after the secondary transmission light returns along the original path, it passes through the fixed focus lens and the filter unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; S4. When the pump source of the laser to be measured is working, the measuring unit is adjusted so that when the detection light spot and the reference light spot meet preset conditions, the corresponding property value of the measuring unit is obtained to determine the thermal effect parameter of the disk laser crystal.

[0036] The present invention creates a measuring device and method for the thermal effect parameters of a disk laser crystal. By constructing a reference optical path and a detection optical path, when the pump source of the laser to be measured is working, the measuring unit of the thermal effect parameters of the disk laser crystal is adjusted so that when the detection light spot of the probe light imaged on the camera and the reference light spot meet the preset conditions, the corresponding attribute value of the measuring unit is obtained, and the thermal effect parameters of the disk laser crystal can be determined. The new measurement technology provided by the technical solution of the present application can not only measure the parameters of the thermal lens effect of the disk laser crystal in the laser to be measured, but also measure the parameters of the hot air wedge effect.

[0037] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

[0038] Example 1 like Figure 1 As shown, a schematic diagram of the structure of a device for measuring the thermal effect parameters of a disk laser crystal provided by an embodiment of the present invention is provided. It can be seen from the figure that the measuring device of this embodiment includes: a first laser 12, a lens group including a first lens 13 and a second lens 14, a beam splitter prism 10, a fixed-focus lens 15, a filtering unit 16, a camera 17, a standard plane mirror 9 and a measuring unit for the thermal effect parameters of a disk laser crystal.

[0039] Among them, the first laser 12 is used to emit probe light, and the wavelength band of the probe light is different from the pump source wavelength band used by the laser to be measured to which the disk laser crystal 8 of the thermal effect parameter to be measured belongs, and the output laser wavelength band of the laser to be measured; the first lens 13, the second lens 14 and the beam splitter prism 10 are arranged in sequence along the light path direction of the first laser 12, and the lens group composed of the first lens 13 and the second lens 14 is used to expand and collimate the probe light emitted by the first laser 12, and the beam splitter prism 10 is used to split the probe light; the fixed-focus lens 15, the filtering unit 16 and the camera 17 are arranged in sequence along the transmission direction of the beam splitter prism 10, so that the probe light emitted by the first laser 12 passes through the lens group and the beam splitter prism 10, and passes through the fixed-focus lens 15 and the filtering unit 16 in sequence, and is imaged on the camera 17, and the imaging spot is the reference spot; the standard plane mirror 9 is arranged along the reflection direction of the probe light after passing through the lens group and reflected by the beam splitter prism 10.

[0040] In this embodiment, a measurement unit for the thermal effect parameters of the disk laser crystal is arranged along the reflection direction of the probe light by the standard plane mirror 9, so that the probe light emitted by the first laser 12 passes through the lens group, is reflected by the dichroic prism 10, and after being reflected by the standard plane mirror 9, is transmitted in the opposite direction of the original light path, is transmitted through the dichroic prism 10 again, passes through the measurement unit, and is focused on the disk laser crystal 8 of the thermal effect parameter to be measured in the laser to be measured, and after being reflected by the disk laser crystal 8, returns to the original path, and is then reflected by the dichroic prism 10, converged by the fixed-focus lens 15, and filtered by the filtering unit 16 in turn, and is imaged on the camera 17. This light spot is the detection light spot.

[0041] In this embodiment, the measuring unit is also used to determine the thermal effect parameters of the disk laser crystal by adjusting the measuring unit when the pump source of the laser to be measured is working, so that the detection light spot and the reference light spot meet the preset conditions and the property value of the measuring unit corresponds to the preset conditions, wherein the preset conditions include: the detection light spot overlaps with the reference light spot, and the diameter parameter difference between the two is the smallest.

[0042] In this embodiment, a reference optical path is formed in sequence by a first laser 12, a first lens 13, a second lens 14, a beam splitter prism 10, a fixed-focus lens 15, a filtering unit 16 and a camera 17; the path of the detection optical path includes: the probe light emitted by the first laser 12 passes through the first lens 13, the second lens 14, and is split by the beam splitter prism 10 to obtain a first reflected light and a first transmitted light; the first reflected light is reflected by a standard plane mirror 9, and then transmitted in the opposite direction of the original optical path, and is split again by the beam splitter prism 10 to obtain a secondary transmitted light and a tertiary reflected light; wherein the secondary transmitted light obtained after transmission, after passing through the measuring unit, is focused on a disk laser crystal 8 of a thermal effect parameter to be measured in the laser to be measured; the secondary transmitted light is returned to the original path by the disk laser crystal 8, and then reflected by the beam splitter prism 10, and converged by the fixed-focus lens 15 and the filtering unit 16, and imaged on the camera 17.

[0043] Among them, the standard plane mirror 9 is used to realize 180° direction reflection of the optical path, and is used to calibrate the detection optical path before measurement; the distance between the fixed focus lens 15 and the camera 17 satisfies the condition that the size of the reference light spot imaged on the camera 17 is the smallest. The filtering unit 16 may include: a bandpass filter or an attenuation plate, which is used to filter out stray light and ambient light generated during the operation of the pump source of the laser to be measured; by setting the filtering unit 16, it can be ensured that the spatial stray light does not affect the measurement result, so as to ensure the accuracy of the measurement result, and the appropriate light intensity attenuation ensures the safety of the measurement device.

[0044] like Figure 1As shown, in this specific embodiment, the measurement unit of the thermal effect parameters of the disk laser crystal includes: an electrodeformation-driven zoom lens 11, a first 45° reflector 19, and a second 45° reflector 20, which are arranged in sequence along the reflection direction of the probe light by the standard plane mirror 9, so that the probe light emitted by the first laser 12 passes through the lens group, is reflected by the beam splitter prism 10, and is reflected by the standard plane mirror 9, and is transmitted in the opposite direction of the original light path, and after being transmitted through the beam splitter prism 10 again, it is focused on the thermal effect parameter to be measured in the laser to be measured after passing through the electrodeformation-driven zoom lens 11, the first 45° reflector 19 and the second 45° reflector 20. The disk laser crystal 8 is provided with a second transmission light, and the second transmission light is returned along the original path, reflected by the beam splitter prism 10 and converged by the fixed focus lens 15 and the filtering unit 16, and imaged on the camera 17, and the light spot is the detection light spot; the measuring unit is also used for determining the thermal effect parameters of the disk laser crystal according to the property value of the measuring unit corresponding to the time when the pump source of the laser to be measured is working, when the pump source of the laser to be measured is working, adjusting the electro-deformation driven zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 so that the detection light spot and the reference light spot meet the preset conditions; wherein the electro-deformation driven zoom lens 11 can provide lenses with different focusing capabilities, so that the incident parallel light is deflected to different degrees.

[0045] In this embodiment, the measurement unit of the thermal effect parameters of the disk laser crystal may also include: a piezoelectric control mirror frame for mounting the first 45° reflector 19 and the second 45° reflector 20; a piezoelectric controller 21, electrically connected to the electrodeformation driven zoom lens 11, and synchronously connected to the piezoelectric control mirror frame, for controlling the electrical yaw and pitch angles of the first 45° reflector and the second 45° reflector; and also for controlling at least two voltages in the electrodeformation driven zoom lens 11 and the piezoelectric mirror frame on which the first 45° reflector 19 and the second 45° reflector 20 are mounted when the pump source of the laser to be measured is working, so that the detection light spot and the reference light spot meet the preset conditions, and the thermal effect parameters of the disk laser crystal are determined according to their respective voltage values ​​and corresponding calibration coefficients.

[0046] The device for measuring the thermal effect parameters of a disk laser crystal provided in this embodiment can measure the thermal effect parameters of a disk laser crystal. The laser to be measured may include a disk pump module. The disk laser crystal and the disk laser are only a specific application scenario applicable to the measuring device provided in the embodiment of the present disclosure, and the disk laser crystal and the disk laser do not constitute a limitation to the embodiment of the present disclosure.

[0047] Specific as Figure 1As shown in , in this embodiment, the disk laser includes in sequence along the light emitting direction of the pump source 1: a pump source 1, used to pump the disk laser; a collimating lens 2, used to collimate the pump source 1; a tertiary reflector 4 and a fourth reflector 5, used to make the pump laser emitted by the pump source 1 travel back and forth in the disk laser crystal 8 for multiple times; the disk laser crystal 8, as a laser gain medium and a reflective element in the disk laser resonant cavity, is also a measured object.

[0048] In this embodiment, from Figure 1 As can be seen, the disk laser can also include: a fixture 3 for keeping the disk laser crystal 8 stable; a coolant 6 and a heat sink 7 for the disk laser crystal, for cooling the disk laser crystal 8 and conducting away the waste heat. The heat sink 7 can usually use diamond or copper tungsten to quickly conduct away the waste heat in the disk laser crystal 8.

[0049] The test device provided in this embodiment measures the thermal effect parameters of the disk laser crystal by: First, the thermal effect parameters of the disk laser crystal may include: a hot air wedge angle α in the hot air wedge effect of the disk laser crystal; The hot air wedge angle α is determined by: α = 2b (V 2 -V 4 ) Among them, V 2 and V 4 a is the piezoelectric voltage value of the first 45° reflector 19 and the piezoelectric voltage value of the second 45° reflector 20 when the pump source of the laser to be tested is working and the detection spot and the reference spot meet the preset conditions; b is the calibration coefficient between the piezoelectric voltage value of the first 45° reflector 19 and the deflection angle when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset conditions. That is, the test device provided by this embodiment can realize the measurement of the hot air wedge angle α in the hot air wedge effect of the disk laser crystal.

[0050] The hot air wedge angle α and its measurement process are further introduced below.

[0051] Before the measurement begins, the relationship between the voltage setting parameters and the corresponding focal length f, yaw angle, pitch angle, etc. is calibrated.

[0052] f 变 = a V 1 β 1 = b V 2 γ 1 = c V 3 β 2 = b V 4 γ 2 = c V 5 Where f becomes the actual focal length of the zoom lens, β 1 and γ 1 is the tilt angle and pitch angle of the first 45° plane reflector, β 2 and γ 2 is the tilt angle and pitch angle of the second 45° reflector, V 1 ~V 5 is the actual voltage value, a~c are the calibration coefficients.

[0053] When the pump light 1 starts working, the disk laser crystal 8 will produce a thermal effect when heated, and the size and position of the detection spot that the camera can see will change. This is caused by the thermal lens effect and the hot air wedge effect. First, the piezoelectric control mirror frame of the first 45° reflector 19 and the second 45° reflector 20 is appropriately adjusted so that the detection spot is at the center of the disk laser crystal, and the detection spot coincides with the reference spot. The image formed by the camera 17 uses image processing technology to extract the center position of the detection spot and the reference spot image, and the diameter data difference between the two is minimized during the adjustment process. Then, the voltage of the electro-deformation driven zoom lens 11 is controlled so that the spot size at the detection spot is equal to the size of the reference spot or the diameter parameter difference between the two is minimized. When adjusting the voltage of the electro-deformation driven zoom lens 11, the voltage value at the piezoelectric control mirror frame of the two 45° reflectors is continuously closed-loop controlled so that the reference spot coincides with the detection spot. After the adjustment is completed, the voltage value at the piezoelectric mirror frame of the electrodeformable drive zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 is read and recorded as V 1 、V 2 、V 3 、V 4 、V 5 The power of the pump light 1 is continuously increased, and the voltages at the piezoelectric control mirror frame of the electrodeformable drive zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 are adjusted in real time, and the above operation is repeated until the measurement is completed.

[0054] The specific measurement principle of the hot air wedge angle α is as follows: like Figure 2 and Figure 3 As shown, Figure 1 Similar to, Figure 2The laser device includes a first 45° reflector 19 and a second 45° reflector 20 mounted on a piezoelectric control mirror frame, and a disk laser crystal 8 mounted on a heat sink 7. Figure 2 It can be seen from the disk laser crystal 82 when the equivalent hot air wedge takes effect that the pitch and yaw of the equivalent disk laser crystal 8 are affected by the hot air wedge effect. By adjusting the pitch and yaw of the first 45° reflector 19 and the second 45° reflector 20, the incident light can still hit the center of the offset disk laser crystal 82. According to the positions of the first 45° reflector 32 with the change in the yaw and pitch of the piezoelectric control mirror frame and the second 45° reflector 42 with the change in the yaw and pitch of the piezoelectric control mirror frame, the effect of the piezoelectric control mirror frame offset after adjustment can be seen. In order to obtain the wedge angle parameters of the hot air wedge effect, Figure 2 The plane position setting shown assumes that due to the hot air wedge effect, the deflection angle of the disc crystal is α, the angle of the first 45° reflector 19 deflected to the position of the first 45° reflector 32 where the piezoelectric control mirror frame deflection and pitch change is x, and the angle of the second 45° reflector 20 deflected to the position of the second 45° reflector 42 where the piezoelectric control mirror frame deflection and pitch change is y.

[0055] To analyze the relationship between α, x and y, the equivalent optical path diagram is as follows Figure 4 As shown, Figure 4 The short and medium dashed lines are discovery and auxiliary lines, and the long dashed lines are the offset light rays.

[0056] Depend on Figure 4 The sum of the interior angles of triangle ABC is 180°, so: 90-α+2 (45-y+α)+2 x=180° 90-α+90-2 y+2α+2 x=180° -α-2 y+2 x=0° but: α=2 (yx) According to the above voltage relationship: y = β 1 = b V 2 x = β 2 = b V 4 but: α = 2b (V 2 -V4 ) Second, the thermal effect parameters of the disk laser crystal include the thermal focal length f in the thermal lens effect of the disk laser crystal. TD ; The thermal focal length f is determined by TD : f TD =a (V 1-1 -V 1-2 ) Wherein, a is the voltage and focal length f of the electro-deformation driven zoom lens 11 when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset condition. 变 Calibration coefficient between 1-1 is the initial voltage of the electro-deformation driven zoom lens 11 when the pump source of the laser to be tested is not working and the detection light spot and the reference light spot meet the preset condition; V 1-2 is the voltage of the electro-deformation drive zoom lens 11 when the pump source of the laser to be tested is working and the detection spot and the reference spot meet the preset condition. That is, the test device provided by this embodiment can realize the thermal focal length f in the thermal lens effect of the disk laser crystal. TD measurement.

[0057] Parameters Thermal focal length f TD The measurement process thereof is similar to the aforementioned description of the hot air wedge angle α and its measurement process, and will not be repeated herein.

[0058] Specific thermal focal length f TD The measurement principle is as follows: like Figure 4 As shown, the electrodeformation-driven zoom lens 52 when measuring the thermal lens effect of the disk laser crystal is the changing state of the electrodeformation-driven zoom lens 11 when the disk laser crystal 8 changes from state 8 to state 83 after being heated. In the initial state of the experiment, the overlap of the reference light spot and the detection light spot has achieved optical path alignment. By changing the focal length of the electrodeformation-driven zoom lens 11, it will be found that the size of the light spot on the camera 17 changes. When the light spot becomes larger, the focal length of the electrodeformation-driven zoom lens 11 is gradually adjusted so that the light spot changes from large to minimum, and the overlap of the reference light spot and the detection light spot is ensured. Since the focal length of the equivalent thermal lens of the disk laser crystal 8 may be large, the electrodeformation-driven zoom lens 11 may be deformed into a negative lens. Assume that the focal length of the electrodeformation-driven zoom lens 11 in the original state is f 1 The focal length of the electro-deformation driven zoom lens 52 when measuring the thermal lens effect of the disk laser crystal is f 2 , then the thermal focal length f of the disk laser crystal 8 is TDThe calculation formula is as follows: f TD =f 1 -f 2 According to the above voltage relationship: f 变 = a V1 but: f TD =a (V 1-1 -V 1-2 ) According to the above transformation relationship, the thermal effect parameters of the disk laser crystal 8 can be obtained in real time.

[0059] The core of the technical solution provided by this embodiment is to measure the thermal effect parameters generated by the disk laser crystal when it is working based on the camera 17 and the interferometric measurement optical path established. Through the reference optical path and the detection optical path in the measuring device, when the pump source of the laser to be measured is working, the measurement unit of the thermal effect parameters of the disk laser crystal is adjusted so that when the detection spot of the probe light imaged on the camera and the reference spot meet the preset conditions, the corresponding attribute value of the measurement unit is obtained, and the thermal effect parameters of the disk laser crystal can be determined. The new measurement technology provided by this technical solution can not only measure the parameters of the thermal lens effect, but also measure the parameters of the hot air wedge effect of the disk laser crystal in the laser to be measured, which can solve the problem that the traditional measurement method is limited to the measurement of the thermal lens effect of the disk laser crystal.

[0060] In this embodiment, the resolution and response speed of the camera 17 meet the preset imaging conditions to improve the resolution and response speed of the camera 17, thereby improving the imaging quality of the reference light spot and the detection light spot, which is beneficial to improving the real-time and accuracy of the thermal effect parameters of the detected disk laser crystal.

[0061] In this embodiment, the measurement unit of the thermal effect parameters of the disk laser crystal may also include: a computer 18, which is connected to the camera 17, the electrodeformation-driven zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 respectively, and is used to obtain the reference light spot and the detection light spot of the camera 17, and is also used to automatically adjust the property values ​​in the electrodeformation-driven zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 when the pump source of the laser to be measured is working, and adjust the electrodeformation-driven zoom lens 11, the first 45° reflector 19, and the second 45° reflector 20 so that the detection light spot and the reference light spot meet the preset conditions. The corresponding property value of the measuring unit is adjusted to achieve automatic closed-loop adjustment of the property value, and automatically calculate and determine the thermal effect parameters of the disk laser crystal 8.

[0062] In this embodiment, the piezoelectric controller 21 is connected to the piezoelectric control mirror frame, and outputs a voltage to control the piezoelectric control mirror frame after receiving a command from the computer 18. The computer 18 is connected to the camera 17 and the piezoelectric control mirror frame for image processing and analysis of the appropriate position of the detection spot and real-time closed-loop control of the piezoelectric control mirror frame.

[0063] Example 2 This embodiment provides a device for measuring the thermal effect parameters of a disk laser crystal, and the main difference from Embodiment 1 is that the measuring unit for the thermal effect parameters of a disk laser crystal includes: a zoom lens group (not shown in the figure), a first 45° reflector 19, and a second 45° reflector 20, which are arranged in sequence along the reflection direction of the probe light by the standard plane mirror 9; wherein the zoom lens group specifically includes: an electrodeformation-driven zoom lens 11 and a preset focus lens.

[0064] The electro-deformation driven zoom lens 11 is used in Example 1, and the zoom lens group consisting of the electro-deformation driven zoom lens 11 and the preset focus lens is used in Example 2. The rest of the structure is the same as that of Example 1, and the measurement method and principle are also similar, which will not be described here.

[0065] Example 3 Figure 5 A schematic structural diagram of a device for measuring thermal effect parameters of a disk laser crystal provided in accordance with another embodiment of the present invention; as can be seen from the figure, the difference between this embodiment and embodiments 1 and 2 is that the measuring unit for the thermal effect parameters of the disk laser crystal comprises: an electro-deformable mirror 22, which may be a 45° piezoelectric deformable mirror mounted on a piezoelectric controlled mirror frame), and a second 45° mirror 19, which may be a 45° plane mirror mounted on a piezoelectric controlled mirror frame.

[0066] Figure 5 Mainly shows Figure 1 The electro-deformable reflector 22 and the second 45° reflector 19 have different structures. At this time, the piezoelectric controller 21 is connected to the computer 18 and the piezoelectric control mirror frame, and outputs a voltage after receiving the command issued by the computer 18 to control the piezoelectric control mirror frame; the rest of the structure can be referred to Figure 1 And related instructions.

[0067] The electro-deformable reflector 22 and the second 45° reflector 19 are sequentially arranged along the reflection direction of the probe light by the standard plane mirror 9, so as to make the probe light emitted by the first laser 12 pass through the first lens group 13, the second lens 14, and be reflected by the dichroic prism 10, and after being reflected by the standard plane mirror 9, be transmitted in the opposite direction of the original light path, and after being transmitted through the dichroic prism 10 again, after passing through the electro-deformable reflector 22 and the second 45° reflector 19, be focused on the disc laser crystal 8 of the thermal effect parameter to be measured in the laser to be measured, and make the secondary transmitted light return along the original path, be reflected by the dichroic prism 10, converged by the fixed-focus lens 15 and the filtering unit 16, and be imaged on the camera 17. This light spot is the detection light spot.

[0068] The measuring unit in this embodiment is also used to determine the thermal effect parameters of the disk laser crystal according to the property value of the measuring unit corresponding to when the pump source 1 of the laser to be measured is working by adjusting the electro-deformable reflector 22 and the second 45° reflector 19 so that the detection spot and the reference spot meet the preset conditions.

[0069] Except for the different structures in the measurement unit, the rest of the structures are the same as those in Example 1. Figure 1 The structures shown are the same, and the measuring methods and principles are similar, so they will not be described in detail here.

[0070] Example 4 Embodiment 4 provides a method for measuring thermal effect parameters of a disk laser crystal, and the measurement is completed based on a device for measuring thermal effect parameters of a disk laser crystal provided in any of the above embodiments.

[0071] For the convenience of description, in combination with the Figure 1 The measurement device structure shown is introduced, but Figure 1 The measuring device does not constitute a limitation to the measuring method provided in this embodiment.

[0072] The measuring method comprises: S1. Control the first laser 12 to emit probe light; S2. Adjust the reference light path to obtain the reference light spot of the probe light imaged in the camera 17; S3. A measurement unit based on the thermal effect parameters of the disk laser crystal obtains the detection spot imaged by the probe light through the detection optical path in the camera 17; S4. When the pump source 1 of the laser to be measured is working, the measuring unit is adjusted so that when the detection spot and the reference spot meet the preset conditions, the corresponding property value of the measuring unit is obtained to determine the thermal effect parameters of the disk laser crystal 8; Wherein: the reference optical path is composed of a first laser 12, a lens group 13, 14, a beam splitter prism 10, a fixed focus lens 15, a filter unit 16 and a camera 17 in sequence; The path of the detection optical path includes: the probe light emitted by the first laser 12 passes through the first lens 13, the second lens 14, and is split by the dichroic prism 10 to obtain a first reflected light and a first transmitted light; the first reflected light is reflected by the standard plane mirror 9 to obtain a second reflected light, which is transmitted in the opposite direction of the original optical path; the second reflected light is split again by the dichroic prism 10 to obtain a second transmitted light and a third reflected light; the second transmitted light passes through the measuring unit and is focused on the disk laser crystal 8 of the thermal effect parameter to be measured in the laser to be measured, and the second transmitted light is returned along the original path, reflected by the dichroic prism 10, converged by the fixed-focus lens 15 and the filtering unit 16, and imaged on the camera 17.

[0073] The preset conditions include: the detection light spot overlaps with the reference light spot, and the diameter parameter difference between the two is minimal. The attribute value may include: a voltage value and a corresponding calibration coefficient; The calibration coefficients are pre-acquired in the following way: Controlling the first laser 12 to emit probe light; Adjust the reference light path to obtain a reference light spot where the probe light is imaged in the camera 17; A measurement unit based on the thermal effect parameters of the disk laser crystal is used to obtain a detection light spot formed by the probe light passing through the detection light path and imaged in the camera 17; When the pump source of the laser to be measured is not working, the measuring unit is adjusted so that the detection light spot and the reference light spot meet a preset condition, and the corresponding initial voltage of the measuring unit and the corresponding calibration coefficient are obtained.

[0074] Specifically, the thermal effect parameters of the disk laser crystal may include: a hot air wedge angle α in the hot air wedge effect of the disk laser crystal. The thermal effect parameters of the disk laser crystal may also include: a thermal focal length f in the thermal lens effect of the thermal effect of the disk laser crystal. TD .

[0075] The specific measurement principle can be found in Example 1. The measurement method provided in this embodiment can be implemented based on the measurement device provided in any embodiment, and has corresponding modules and beneficial effects. On the one hand, it can synchronously measure the thermal lens effect parameters and hot air wedge effect parameters in the thermal effect of the disk laser crystal in various types of lasers (such as disk lasers); the required measurement device occupies a small space. On the other hand, once the measurement device is calibrated, the computer autonomously performs closed-loop operation to control the voltage, and the measurement operation is simple; moreover, the process of measuring the thermal focal length is not affected by the hot air wedge effect parameters, and the measurement result is relatively accurate.

[0076] It is worth noting that the various units and modules included in the above-mentioned device are only divided according to functional logic, but are not limited to the above-mentioned division, as long as the corresponding functions can be achieved; in addition, the specific names of the functional units are only for the convenience of distinguishing each other, and are not used to limit the protection scope of the embodiments of the present disclosure.

[0077] The measuring device provided in the embodiment of the present disclosure and the measuring method provided in the above embodiment belong to the same inventive concept. The technical details not fully described in the embodiment of the present disclosure can be referred to the above embodiment, and the embodiment of the present disclosure has the same beneficial effects as the above embodiment.

[0078] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for measuring thermal effect parameters of a disk laser crystal, characterized in that: The measuring device comprises a first laser, a lens group, a beam splitter prism, a fixed focus lens, a filtering unit, an imaging unit, a standard plane mirror and a measuring unit; The lens group and the beam splitter prism are sequentially arranged along the light path direction of the first laser to emit probe light, the probe light is expanded and collimated by the lens group, and then split by the beam splitter prism to obtain a primary transmitted light and a primary reflected light respectively; The fixed-focus lens, the filtering unit and the camera are sequentially arranged along the optical path direction of the primary transmitted light, and the standard plane mirror is arranged along the optical path direction of the primary reflected light; after the primary reflected light is reflected by the standard plane mirror, secondary reflected light is obtained, and the measuring unit is arranged along the optical path direction of the secondary reflected light; After the primary transmitted light passes through the fixed-focus lens and the filtering unit in sequence, it is imaged on the imaging unit, and the obtained imaging light spot is the reference light spot; The secondary reflected light is transmitted to the beam splitter prism, and is split by the beam splitter prism to obtain secondary transmitted light and tertiary reflected light respectively; the secondary transmitted light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; After being reflected by the disk laser crystal, the secondary transmitted light returns along the original path, and after the secondary transmitted light returns along the original path, it passes through the fixed focus lens and the filter unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; When the pump source of the laser to be measured is working, the measurement unit is adjusted so that the detection light spot and the reference light spot meet preset conditions, and the thermal effect parameters of the disk laser crystal are determined according to the corresponding attribute values ​​of the measurement unit; the preset conditions include that the detection light spot overlaps with the reference light spot, and the diameter parameter difference between the detection light spot and the reference light spot is minimal.

2. The device for measuring thermal effect parameters of a disk laser crystal according to claim 1, characterized in that: The measuring unit comprises an electrodeformation driven zoom lens, a first 45° reflecting mirror, and a second 45° reflecting mirror, which are sequentially arranged along the optical path direction of the secondary reflected light.

3. The device for measuring thermal effect parameters of a disk laser crystal according to claim 2, characterized in that: The measuring unit also includes a piezoelectric control mirror frame and a piezoelectric controller; The piezoelectric controlled mirror frame is used to mount the first 45° reflector and the second 45° reflector; The piezoelectric controller is electrically connected to the electrodeformation driven zoom lens; The piezoelectric controller is connected to the piezoelectric control mirror frame and is used to control the yaw and pitch angles of the first 45° reflector and the second 45° reflector.

4. The device for measuring thermal effect parameters of a disk laser crystal according to claim 2, characterized in that: The thermal effect parameters of the disk laser crystal include the hot air wedge angle α in the hot air wedge effect of the disk laser crystal. The calculation formula of the hot air wedge angle α is: α= 2b (V2-V4); Among them, b is the calibration coefficient between the piezoelectric voltage value and the deflection angle of the first 45° reflector when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset conditions; V2 and V4 are the piezoelectric voltage value of the first 45° reflector and the piezoelectric voltage value of the second 45° reflector, respectively, when the pump source of the laser to be tested is working and the detection spot and the reference spot meet the preset conditions.

5. The device for measuring thermal effect parameters of a disk laser crystal according to claim 2, characterized in that: The thermal effect parameters of the disk laser crystal include the thermal focal length f in the thermal lens effect of the disk laser crystal. TD , the thermal focal length f TD The calculation formula is: f TD =a (V 1-1 -V 1-2 ) Wherein, a is the voltage and focal length f of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection spot and the reference spot meet the preset condition. 变 Calibration coefficient between 1-1 is the initial voltage of the electro-deformation driven zoom lens when the pump source of the laser to be tested is not working and the detection light spot and the reference light spot meet the preset condition; V 1-2 It is the voltage of the electro-deformation driving zoom lens when the pump source of the laser to be tested works and the detection light spot and the reference light spot meet the preset condition.

6. The device for measuring thermal effect parameters of a disk laser crystal according to claim 1, characterized in that: The measuring unit comprises a zoom lens group, a first 45° reflector and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light; The zoom lens group includes an electro-deformation driven zoom lens and a preset focus lens.

7. The device for measuring thermal effect parameters of a disk laser crystal according to claim 1, characterized in that: The measuring unit comprises an electro-deformable reflector and a second 45° reflector, which are sequentially arranged along the optical path direction of the secondary reflected light.

8. The device for measuring thermal effect parameters of a disk laser crystal according to claim 1, characterized in that: The laser to be tested includes a disk pump module; The disk pump module includes, in sequence along the light emitting direction of the pump source: A pump source, used for pumping the disk laser crystal; A collimating lens, used to collimate the pump source; The tertiary reflecting mirror and the fourth reflecting mirror are used to make the pump laser emitted by the pump source travel back and forth in the disk laser crystal for multiple times; and disk laser crystals.

9. The device for measuring thermal effect parameters of a disk laser crystal according to claim 1, characterized in that: The property value of the measurement unit includes a voltage value and a corresponding calibration coefficient.

10. A method for measuring thermal effect parameters of a disk laser crystal, characterized in that: The measuring method is implemented by the measuring device according to any one of claims 1 to 9, and the measuring method comprises the steps of: S1. Controlling the first laser to emit the probe light; S2. Adjust the reference light path to obtain a reference light spot imaged in the imaging unit; The reference optical path is composed of the first laser, the lens group, the beam splitter prism, the fixed focus lens, the filtering unit and the imaging unit in sequence; S3. By means of the measuring unit, adjusting the detection light path, the path of the detection light path includes: The probe light is expanded and collimated by the lens group, and then split by the beam splitter prism to obtain a primary transmitted light and a primary reflected light respectively; the primary reflected light is reflected by the standard plane mirror to obtain a secondary reflected light; the secondary reflected light is transmitted to the beam splitter prism, and split by the beam splitter prism to obtain a secondary transmitted light and a tertiary reflected light respectively; the secondary transmitted light is measured by the measuring unit and focused on the disk laser crystal in the laser to be measured; after being reflected by the disk laser crystal, the secondary transmitted light returns along the original path, and after the secondary transmitted light returns along the original path, it passes through the fixed focus lens and the filter unit in sequence, and is imaged on the imaging unit, and the obtained imaging light spot is the detection light spot; S4. When the pump source of the laser to be measured is working, adjust the measuring unit so that the detection light spot and the reference light spot meet preset conditions, obtain the corresponding attribute value of the measuring unit, and determine the thermal effect parameter of the disk laser crystal.

Images