Solid laser module capable of monitoring pump light performance in real time and working method thereof

Abstract

The invention relates to a solid laser module capable of monitoring pumping light performance in real time and a working method thereof, and belongs to the technical field of lasers, and the solid laser module comprises a pumping laser diode array, a laser diode heat sink, a light gathering cavity, a laser gain medium, a glass tube and a photoelectric detector. According to the invention, the working state of the semiconductor laser array which is hermetically packaged in the solid laser module and is distributed around the laser gain medium in a certain space can be monitored in real time. In the long-term use of the solid laser module, due to the change of the radiation performance of individual or partial pumping LDs, the gain distribution of an irradiated laser gain medium can be changed, and the laser performance of the solid laser module is influenced. According to the invention, the positions of some LDs of which the light emitting states are changed in the use process can be accurately positioned, so that the LDs can be repaired or replaced in time, and long-term stable work of a laser system is guaranteed.

Description

Technical Field

[0001] The invention relates to a solid laser module capable of real-time monitoring of pump light performance and a working method thereof, belonging to the technical field of lasers. Background Art

[0002] Solid-state laser modules are important laser oscillators and power amplifiers that generate high-energy, high-power lasers. They have very important applications in the field of high-power lasers due to their significant advantages such as high stored photon energy, compact structure, and low cost. In solid-state laser modules, LD arrays are usually used as pump sources. The emitted LD pump light irradiates the laser gain medium from the side perpendicular to the laser transmission axis, causing the number of particles in the laser gain medium to reverse.

[0003] In the LD side pump module in the prior art, there is no device for real-time monitoring of the luminescence performance of the pump LD. When the performance of the laser emitted by the laser system changes, it is impossible to determine whether it is caused by changes in the luminescence characteristics of some pump LD arrays in the solid laser module used by the system. During the long-term use of the laser, the radiation performance of the pump LD will change due to the consistency of the product quality and service life of the pump LD, which will change the gain of the irradiated laser gain medium and produce a deviation from the initial design gain of the solid laser module required by the laser system. This deviation has many adverse effects on the application of the laser and may even seriously damage the laser system. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a solid-state laser module capable of real-time monitoring of pump light performance and a working method thereof, which can monitor the working status of a pump LD array that is sealed inside the solid-state laser module and arranged in a certain space around a laser gain medium in real time during the operation of the module.

[0005] The technical solution of the present invention is:

[0006] A solid laser module capable of real-time monitoring of pump light performance, comprising a laser gain medium, a glass tube, a focusing cavity, a pump LD array, an LD heat sink and a photodetector;

[0007] The glass tube is coaxially placed with the laser gain medium and has high transmittance to the pump light emitted by the pump LD array; a strip-shaped light-through hole is provided between the multiple focusing cavities, the pump LD array and the strip-shaped light-through hole are arranged correspondingly, and the laser of the pump LD array is incident on the glass tube and the laser gain medium through the strip-shaped light-through hole;

[0008] The photoelectric detector is arranged on the light focusing cavity and corresponds to the pump LD array.

[0009] Preferably, the laser gain medium is in a rod shape, including but not limited to laser ceramic materials and laser crystal materials.

[0010] Preferably, a cooling liquid is passed between the glass tube and the laser gain medium to cool the laser gain medium.

[0011] Preferably, the pump LD array is pulse or continuous pumping, and includes a plurality of LD bars with consistent wavelengths arranged at intervals along the axial direction of the laser gain medium.

[0012] Preferably, the pump LD array is placed on an LD heat sink, and the temperature of the LD heat sink is controlled by a cooling liquid.

[0013] Preferably, the number of LD heat sinks is an odd number, and the LD heat sinks are evenly distributed along the circumference of the laser gain medium. A strip-shaped light hole is opened on the focusing cavity, and the pump light emitted by the pump LD array is emitted to the laser gain medium through the strip-shaped light hole, and the LD pump light not absorbed by the laser gain medium can be partially reflected by the surface of the focusing cavity and then irradiated to the laser gain medium again for absorption.

[0014] Preferably, a small hole is opened on the focusing cavity opposite to the pump LD array, a photodetector is placed in the small hole, the detection surface of the photodetector faces the laser working medium, and the LD pump light emitted by the pump LD array is irradiated onto the photodetector through the small hole.

[0015] Preferably, the number of photodetectors is the same as the number of LD bars in the pump LD array.

[0016] A working method of the solid-state laser module capable of real-time monitoring of pump light performance comprises:

[0017] The laser gain medium is pumped by a pump LD array, and the pump light is irradiated into the laser gain medium through a glass tube, wherein most of the LD pump light is absorbed by the laser gain medium, and a small portion of the LD pump light that is not absorbed by the laser gain medium will irradiate the photodetector, thereby enabling the photodetector to monitor the intensity changes of the LD pump light emitted by the pump LD array in real time.

[0018] Preferably, after the pump LD array is powered on, the pump LD array emits pump light, which passes through the glass tube and is incident on the interior of the laser gain medium. Part of the LD pump light that is not absorbed by the laser gain medium passes through the glass tube and the small holes on the surface of the focusing cavity and irradiates the photodetector on the opposite side, so that the photodetector outputs a current signal that is proportional to the intensity of the received LD pump light. When the solid laser module is used for a long time, due to differences in the consistency of LD bar product quality and service life, the radiation intensity of individual or part of the LD bars on the LD array changes, causing the current signal output by the photodetector to change accordingly, and the LD pump light performance of the pump LD array is monitored in real time through the degree of change in the current signal output by the photodetector.

[0019] For any details not provided in the present invention, please refer to the prior art.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention has the characteristic of real-time performance and can monitor the luminescence state of the pump LD array in real time.

[0022] 2. The present invention can receive the intensity changes of the pump light through various photodetectors, and accurately locate the position of the pump LD array where the bars where the light-emitting state changes during the use of the laser are located, so that these bars can be repaired or replaced in time to ensure the long-term stable operation of the laser system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings in the specification, which constitute a part of the present application, are used to provide further understanding of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute improper limitations on the present application.

[0024] Figure 1 is a cross-sectional schematic diagram of a solid laser module of the present invention;

[0025] Figure 2 This is a schematic diagram of the real-time monitoring principle of the solid laser module of the present invention;

[0026] In the figure, 1-laser gain medium, 2-glass tube, 3-focusing cavity, 4-pump LD array, 5-LD heat sink, 6-photodetector. DETAILED DESCRIPTION

[0027] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the drawings in the implementation of this specification, but are not limited to this. Anything not fully described in the present invention shall be based on the conventional technology in the art.

[0028] Example 1

[0029] A solid-state laser module capable of real-time monitoring of pump light performance, such as Figure 1 As shown, it includes a laser gain medium 1, a glass tube 2, a focusing cavity 3, a pump LD array 4, an LD heat sink 5 and a photodetector 6;

[0030] The glass tube 2 is coaxially placed with the laser gain medium 1 and has high transmittance to the pump light emitted by the pump LD array 4; a strip-shaped light-through hole is provided between the plurality of focusing cavities 3, and the pump LD array 4 is arranged corresponding to the strip-shaped light-through hole, and the laser of the pump LD array 4 is incident on the glass tube 2 and the laser gain medium 1 through the strip-shaped light-through hole;

[0031] The photodetector 6 is disposed on the light focusing cavity and corresponds to the pump LD array 4 .

[0032] The photodetector 6 monitors the light-emitting state of the pump LD array 4 by the intensity change of the received LD pump light, such as Figure 2 As shown, the signal obtained by the photoelectric detector 6 is stored and processed by the data processing module, and the signals of different detectors can be observed in real time through the display, thereby realizing real-time monitoring, which has the characteristics of real-time performance.

[0033] The laser gain medium 1 provides the inversion particle number required to generate laser oscillation under the irradiation of the pump LD array 4. The laser gain medium is in the shape of a rod, including but not limited to laser ceramic materials, laser crystal materials, and can also be laser media, glass, ceramics, optical fibers, etc. that are singly doped, bonded, or glued with rare earth ions. The type of laser gain medium 1 is selected according to the required laser wavelength, and the doping concentration and size of the gain medium are selected according to the required output energy (or power). In this embodiment, the laser gain medium uses a Nd:YAG crystal rod with a diameter of 5 mm and a doping concentration of 0.8 at.%.

[0034] A coolant is passed between the glass tube 2 and the laser gain medium 1 to cool the laser gain medium. The glass tube 2 is used as a coolant channel and needs to transmit the pump light. It needs to be selected according to the transmittance of the pump light. The size of the glass tube can be selected according to the flow rate and pressure of the coolant. In this embodiment, a high transmittance of 808nm pump light is required, so the glass tube is made of quartz material with an inner diameter of 8mm and an outer diameter of 10mm.

[0035] The pump LD array 4 works in a continuous pumping mode, and the central wavelength of the pump light is 808 nm. The number of LD bars in the pump LD array is 5, and the output power of each LD bar is 40W.

[0036] The material and structure of the LD heat sink 5 are designed and determined according to the requirements of the pump LD array heat generation, temperature control, etc. The pump LD array is placed on the LD heat sink, and the temperature of the LD heat sink is controlled by a coolant.

[0037] The number of LD heat sinks is odd, and the LD heat sinks are evenly distributed along the circumference of the laser gain medium. A strip-shaped light hole is opened on the focusing cavity, and the pump light emitted by the pump LD array is emitted to the laser gain medium through the strip-shaped light hole, and the LD pump light that is not absorbed by the laser gain medium can be partially reflected by the surface of the focusing cavity and irradiated to the laser gain medium again for absorption.

[0038] A 0.5mm×0.5mm small hole is opened on the focusing cavity opposite to the pump LD array. A photodetector 6 is placed in the small hole. The detection surface of the photodetector 6 faces the laser working medium. The LD pump light emitted by the pump LD array irradiates the photodetector through the small hole.

[0039] The number of the photodetectors 6 is the same as the number of LD bars in the pump LD array 4 .

[0040] Example 2

[0041] A working method of the solid-state laser module capable of real-time monitoring of pump light performance comprises:

[0042] The laser gain medium is pumped by a pump LD array, and the pump light is irradiated into the laser gain medium through a glass tube, wherein most of the LD pump light is absorbed by the laser gain medium, and a small portion of the LD pump light that is not absorbed by the laser gain medium will irradiate the photodetector, thereby enabling the photodetector to monitor the intensity changes of the LD pump light emitted by the pump LD array in real time.

[0043] After the pump LD array is powered on, the pump LD array emits pump light, which passes through the glass tube and is incident on the laser gain medium. Some of the LD pump light that is not absorbed by the laser gain medium passes through the glass tube and the small holes on the surface of the focusing cavity and irradiates the photodetector on the opposite side, causing the photodetector to output a current signal that is proportional to the intensity of the received LD pump light. When the solid-state laser module is used for a long time, due to the consistency of the quality of the LD bar products and the difference in service life, the radiation intensity of individual or part of the LD bars on the LD array changes, causing the current signal output by the photodetector to change accordingly. The LD pump light performance of the pump LD array is monitored in real time by the degree of change in the current signal output by the photodetector.

[0044] The research results show that when the output power of the LD bar is 40W when it is working normally, the LD pump power received by the photodetector is 85.2mW; when the output power of the LD bar is reduced to 35W, the LD pump light power received by the photodetector 6 opposite to the LD bar is 77.1mW, which is 9.5% lower than when the LD bar is working normally. The pump light power received by the two photodetectors adjacent to the photodetector 6 becomes 82.1mW, and the LD pump light power received by the two photodetectors adjacent to the LD bar becomes 83.9mW accordingly. Therefore, when the output power of a certain LD bar in the pump LD array changes, the LD pump light power received by the photodetectors at different positions will change to different degrees. According to the degree of change, the position of the LD bar in the abnormal light-emitting state can be accurately located, so that the LD bar can be repaired or replaced in time to ensure the long-term stable operation of the laser system.

[0045] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A solid-state laser module capable of real-time monitoring of pump light performance, characterized in that: Including laser gain medium, glass tube, focusing cavity, pump LD array, LD heat sink and photodetector; The glass tube is coaxially placed with the laser gain medium, a strip-shaped light-through hole is provided between the multiple focusing cavities, the pump LD array is arranged corresponding to the strip-shaped light-through hole, and the laser of the pump LD array is incident on the glass tube and the laser gain medium through the strip-shaped light-through hole; The photoelectric detector is arranged on the light focusing cavity and corresponds to the pump LD array.

2. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 1, characterized in that: The laser gain medium is in a rod shape, including but not limited to laser ceramic materials and laser crystal materials.

3. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 2, characterized in that: A cooling liquid is passed between the glass tube and the laser gain medium to cool the laser gain medium.

4. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 3, characterized in that: The pump LD array is pulse or continuous pumping, and includes a plurality of LD bars with consistent wavelengths arranged at intervals along the axial direction of the laser gain medium.

5. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 4, characterized in that: The pump LD array is placed on an LD heat sink, and the temperature of the LD heat sink is controlled by a cooling fluid.

6. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 5, characterized in that: The number of LD heat sinks is an odd number, and the LD heat sinks are evenly distributed along the circumference of the laser gain medium.

7. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 6, characterized in that: A small hole is opened on the focusing cavity opposite to the pump LD array, and a photodetector is placed in the small hole. The detection surface of the photodetector faces the laser working medium, and the LD pump light emitted by the pump LD array is irradiated onto the photodetector through the small hole.

8. The solid-state laser module capable of real-time monitoring of pump light performance according to claim 7, characterized in that: The number of photodetectors is the same as the number of LD bars in the pump LD array.

9. A method for operating a solid-state laser module capable of real-time monitoring of pump light performance according to claim 8, characterized in that: include: The laser gain medium is pumped by a pump LD array, and the pump light is irradiated into the laser gain medium through a glass tube, wherein most of the LD pump light is absorbed by the laser gain medium, and a small portion of the LD pump light that is not absorbed by the laser gain medium will irradiate the photodetector, thereby enabling the photodetector to monitor the intensity changes of the LD pump light emitted by the pump LD array in real time.

10. The working method of the solid-state laser module capable of real-time monitoring of pump light performance according to claim 9, characterized in that: After the pump LD array is powered on, the pump LD array emits pump light, which passes through the glass tube and is incident on the laser gain medium. Some of the LD pump light that is not absorbed by the laser gain medium passes through the glass tube and the small holes on the surface of the focusing cavity and irradiates the photodetector on the opposite side, causing the photodetector to output a current signal that is proportional to the intensity of the received LD pump light. When the solid laser module is used for a long time, due to the consistency of LD bar product quality and service life, the radiation intensity of individual or part of the LD bars on the LD array changes, causing the current signal output by the photodetector to change accordingly. The LD pump light performance of the pump LD array is monitored in real time by the degree of change of the current signal output by the photodetector.

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