CN119674686A - A device for automatically adjusting the mode ratio of a solid-state laser and a method for adjusting the same - Google Patents
A device for automatically adjusting the mode ratio of a solid-state laser and a method for adjusting the same Download PDFInfo
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Abstract
本发明提供一种自动调节固体激光器模式比的装置及其调节方法，上述自动调节固体激光器模式比的装置首先通过测量模块测量输出镜位置处输出激光的光斑半径以及谐振腔的腔长，得到测试数据，之后位移控制模块根据固体激光器的预设模式比和测量数据调节谐振腔的腔长，以控制输出激光在激光晶体中的光斑半径，从而使固体激光器的实际模式比与预设模式比的差值绝对值小于等于0.01，进而提升了固体激光器的转换效率以及输出激光功率。同时，本发明提供的自动调节固体激光器模式比的装置具有结构简单、稳定可靠以及控制精度高等特点，能够根据需求快速准确地调节固体激光器模式比。
The present invention provides a device for automatically adjusting the mode ratio of a solid-state laser and a method for adjusting the mode ratio of the solid-state laser. The device for automatically adjusting the mode ratio of the solid-state laser first measures the spot radius of the output laser at the output mirror position and the cavity length of the resonant cavity through a measuring module to obtain test data. Then, the displacement control module adjusts the cavity length of the resonant cavity according to the preset mode ratio of the solid-state laser and the measured data to control the spot radius of the output laser in the laser crystal, so that the absolute value of the difference between the actual mode ratio of the solid-state laser and the preset mode ratio is less than or equal to 0.01, thereby improving the conversion efficiency and output laser power of the solid-state laser. At the same time, the device for automatically adjusting the mode ratio of the solid-state laser provided by the present invention has the characteristics of simple structure, stable and reliable, high control accuracy, etc., and can quickly and accurately adjust the mode ratio of the solid-state laser according to needs.
Description
Technical Field
The invention relates to the technical field of solid lasers, in particular to a device for automatically adjusting the mode ratio of a solid laser and an adjusting method thereof.
Background
With the rapid development of solid laser technology, diode pumped solid lasers benefit from the advantages of simple structure, small volume and weight, high conversion efficiency, good stability and the like, and are widely applied to the fields of industry, scientific research, biology, medical treatment and the like. For diode end-pumped solid-state lasers, how to match the output laser spot radius with the pump light spot radius is an important factor in designing the structure of the solid-state lasers and also in improving the output power and conversion efficiency of the solid-state lasers. The mode ratio of the solid-state laser (i.e., the ratio of the spot radius of the output laser light in the laser crystal to the spot radius of the pump light in the laser crystal) is generally considered to be in the interval of 0.8-1.5, and the solid-state laser has higher output power and conversion efficiency.
However, due to the thermal lens effect of the solid-state laser, the spot radius of the output laser in the laser crystal can be changed along with the change of the pumping power, so that the mode ratio of the solid-state laser is changed, the efficiency of the solid-state laser is reduced, and the further improvement of the output power of the solid-state laser is limited.
Therefore, how to adjust the parameters of the laser and change the radius of the light spot of the output laser in the laser crystal under different pumping powers in the design process of the solid laser, so that the mode ratio of the solid laser is in a proper error range is a problem to be solved urgently.
Disclosure of Invention
The invention aims to provide a device for automatically adjusting the mode ratio of a solid laser and an adjusting method thereof, which are used for solving the technical problem that the mode ratio of the solid laser in the prior art is difficult to be in a proper error range under different pumping powers.
In order to solve the above technical problems, the present invention provides a device for automatically adjusting a mode ratio of a solid laser, including:
the pumping module is used for generating pumping light and coupling the pumping light into the resonant cavity;
the resonant cavity is optically connected with the pumping module and comprises an input mirror, a laser crystal and an output mirror which are sequentially optically connected, and the incident end face of the laser crystal is tightly attached to the input mirror;
the measuring module is closely attached to the emergent end face of the output mirror and is used for measuring the spot radius of the output laser at the position of the output mirror and the cavity length of the resonant cavity to obtain test data;
and the displacement control module is electrically connected with the measurement module and is used for adjusting the cavity length of the resonant cavity according to the preset mode ratio and the measurement data of the solid laser so that the absolute value of the difference between the actual mode ratio and the preset mode ratio of the solid laser is smaller than or equal to 0.01.
Preferably, the pump module is arranged near the incident side of the input mirror, and the pump module comprises a pump source, a transmission optical fiber and a coupling lens group;
One end of the transmission optical fiber is welded with the pump source, and the coupling lens group is positioned between the transmission optical fiber and the input mirror.
Preferably, the pump source is a laser diode, and the coupling lens group includes two focusing lenses disposed parallel to each other.
Preferably, the input mirror is a concave mirror, the incident plane of the input mirror is plated with a pumping light antireflection film, the emergent concave surface of the input mirror is plated with a laser high reflection film, the laser high reflection film is used for reflecting output laser stimulated and output by the laser crystal, the output mirror is a concave mirror, and the transmittance of the output mirror to the output laser is 2% -30%.
Preferably, the laser crystal comprises a rare earth doped laser crystal and the measurement module comprises a CCD camera.
Preferably, the displacement control module comprises an electric displacement platform controller and a high-precision electric displacement platform, wherein the electric displacement platform controller is respectively and electrically connected with the high-precision electric displacement platform and the measurement module, and the input mirror and the output mirror are both fixed on the high-precision displacement platform.
Correspondingly, the invention also provides an adjusting method for automatically adjusting the mode ratio of the solid laser by adopting the device for automatically adjusting the mode ratio of the solid laser, which comprises the following steps:
s10, providing a device for automatically adjusting the mode ratio of the solid laser, and determining the pumping power of a pumping module and the preset mode ratio;
S20, measuring the spot radius of the output laser at the position of the output mirror under the current pumping power and the initial cavity length corresponding to the resonant cavity at the moment by using a measuring module to obtain test data;
S30, the displacement control module adjusts the cavity length of the resonant cavity according to the preset mode ratio and the test data so that the absolute value of the difference between the actual mode ratio and the preset mode ratio of the solid laser is smaller than or equal to 0.01.
Preferably, the step S30 specifically includes:
s301, calculating to obtain an equivalent curvature radius of the input mirror according to the initial cavity length, the curvature radius of the output mirror, the wavelength of the output laser and the spot radius of the output laser at the position of the output mirror under the current pumping power;
S302, calculating according to a preset mode ratio, a spot radius of pump light in a laser crystal, an equivalent curvature radius of an input mirror, a curvature radius of an output mirror and a wavelength of output laser to obtain a target cavity length which accords with the preset mode ratio;
s303, the displacement control module controls the high-precision electric displacement platform to adjust the cavity length of the resonant cavity from the initial cavity length to the target cavity length.
Preferably, in step S301, the calculation formula of the equivalent radius of curvature of the input mirror is as follows:
;
Wherein R' is the equivalent radius of curvature of the input mirror, L cav is the initial cavity length, R 2 is the radius of curvature of the output mirror, lambda is the wavelength of the output laser, and omega is the spot radius of the output laser at the position of the output mirror under the current pumping power.
Preferably, in step S302, the calculation formula of the target cavity length is as follows:
;
Wherein L cav' is the target cavity length, r is the preset mode ratio, and omega p is the spot radius of the pump light in the laser crystal.
The device for automatically adjusting the mode ratio of the solid laser and the adjusting method thereof have the beneficial effects that the device is different from the prior art, the device for automatically adjusting the mode ratio of the solid laser firstly measures the spot radius of output laser at the position of an output mirror and the cavity length of a resonant cavity through a measuring module to obtain test data, and then a displacement control module adjusts the cavity length of the resonant cavity according to the preset mode ratio and the measuring data of the solid laser so as to control the spot radius of the output laser in a laser crystal, so that the absolute value of the difference value between the actual mode ratio and the preset mode ratio of the solid laser is smaller than or equal to 0.01, and further the conversion efficiency and the output laser power of the solid laser are improved. Meanwhile, the device for automatically adjusting the mode ratio of the solid laser has the characteristics of simple structure, stability, reliability, high control precision and the like, and can quickly and accurately adjust the mode ratio of the solid laser according to requirements.
Drawings
FIG. 1 is a schematic diagram of a device for automatically adjusting the mode ratio of a solid-state laser according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of connection of an apparatus for automatically adjusting a mode ratio of a solid-state laser according to an embodiment of the present invention;
FIG. 3 is a flowchart of an adjusting method for automatically adjusting the mode ratio of a solid-state laser according to an embodiment of the present invention;
In the figure, 100-an automatic solid laser mode ratio adjusting device, 10-a pumping module, 11-a pumping source, 12-a transmission optical fiber, 13-a coupling lens group, 20-a resonant cavity, 21-an input mirror, 22-a laser crystal, 23-an output mirror, 30-a measuring module, 40-a displacement control module, 41-a high-precision electric displacement platform and 42-an electric displacement platform controller.
Detailed Description
The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present invention without making any inventive effort, are intended to fall within the scope of the present invention.
The invention aims at overcoming the defects of the prior art, and provides a device for automatically adjusting the mode ratio of a solid laser, which can realize the adjustment of the mode ratio of the solid laser.
Referring to fig. 1 to 2, fig. 1 is a schematic diagram of a frame of an apparatus 100 for automatically adjusting a mode ratio of a solid-state laser according to an embodiment of the present invention, and fig. 2 is a schematic diagram of a connection of the apparatus 100 for automatically adjusting a mode ratio of a solid-state laser according to an embodiment of the present invention, wherein the apparatus 100 for automatically adjusting a mode ratio of a solid-state laser according to an embodiment of the present invention includes:
a pump module 10 for generating pump light and coupling into the resonant cavity 20;
the resonant cavity 20 is optically connected with the pumping module 10 and comprises an input mirror 21, a laser crystal 22 and an output mirror 23 which are sequentially optically connected, and the incident end face of the laser crystal 22 is tightly attached to the input mirror 21;
The measuring module 30 is arranged close to the emergent end face of the output mirror 23 and is used for measuring the spot radius of the output laser at the position of the output mirror 23 and the cavity length of the resonant cavity 20 to obtain test data;
The displacement control module 40 is electrically connected to the measurement module 30, and is configured to adjust the cavity length of the resonant cavity 20 according to the preset mode ratio and the measurement data of the solid-state laser, so that the absolute value of the difference between the actual mode ratio and the preset mode ratio of the solid-state laser is less than or equal to 0.01.
In the embodiment of the present invention, the pump module 10 is disposed near the incident side of the input mirror 21, and the pump module 10 includes a pump source 11, a transmission fiber 12, and a coupling lens group 13;
Wherein one end of the transmission fiber 12 is fused with the pump source 11, and the coupling lens group 13 is located between the transmission fiber 12 and the input mirror 21.
Specifically, the pump source 11 is used to generate pump light, and the transmission fiber 12 is mainly responsible for efficiently transmitting the pump light to the focal position on the incident side of the coupling lens group 13. In this process, its good light transmission performance ensures that the pump light energy is lost as little as possible, thereby providing sufficient energy for laser generation.
Specifically, the coupling lens group 13 is used to focus the pump light transmitted through the transmission fiber 12 into the laser crystal 22. At this time, the spot radius of the pump light in the laser crystal 22 can be precisely controlled by the coupling lens group 13.
Preferably, the pump source 11 is a laser diode and the coupling lens group 13 comprises two focusing lenses arranged parallel to each other.
In embodiments of the present invention, the most important function of the resonator 20 is to provide an optical feedback mechanism. When a lasing medium, such as laser crystal 22, is subjected to pump light to effect population inversion to produce stimulated radiation, there is an initial photon emission. These photons are reflected back and forth within the cavity 20, causing more stimulated radiation each time they pass through the lasing medium, resulting in an ever increasing number of photons. For example, in a simple resonant cavity 20 formed by two parallel mirrors, photons travel back and forth between the mirrors, as in an "optical whispering gallery", constantly interacting with the lasing medium, thereby amplifying the optical signal and ultimately achieving laser oscillation. This optical feedback is one of the key conditions for generating laser light, and stable laser light output can be formed only when the light can be effectively fed back and continuously amplified in the cavity.
Specifically, the input mirror 21 is a concave mirror, the incident plane of the input mirror 21 is coated with a pumping light antireflection film, the emergent concave surface of the input mirror 21 is coated with a laser high reflection film, and the laser high reflection film is used for reflecting the output laser stimulated and output by the laser crystal 22;
The main function of the incident surface of the input mirror 21 is to reduce the reflection loss of the pump light when the pump light enters the input mirror 21, and the emergent surface of the input mirror 21 is coated with a laser high reflection film which is mainly used for reflecting the output laser excited and output by the laser crystal 22. Inside the resonator 20, the laser crystal 22 is excited by the pump light to generate output laser light. The part of the output laser propagates in the resonant cavity 20, and when reaching the emergent surface of the input mirror 21, the laser high-reflection film can reflect the output laser back to the resonant cavity 20, so that the output laser continuously reciprocates in the resonant cavity 20, thereby realizing gain amplification of light and finally forming stable laser output.
In embodiments of the present invention, laser crystal 22 comprises a rare earth doped laser crystal, preferably a Nd: YLF crystal, which has a natural birefringence characteristic that makes it particularly advantageous in certain laser applications, for example, by utilizing its birefringence characteristics for polarization control and frequency conversion of the laser light.
In the embodiment of the invention, the output mirror 23 is a concave mirror, and the transmittance of the output mirror 23 to output laser is 2% -30%. When a concave mirror is used as the output mirror 23, the laser light can be focused or collimated. If the design is reasonable, the concave mirror can change the divergence degree of the laser, and the originally diverged laser is converged to a specific area, or the converged laser is adjusted to be parallel beam for output.
Specifically, the output mirror 23 has a transmittance of 2% -30% for the output laser, and the transmittance in this range can effectively control the output energy of the laser. The lower transmittance means that most of the laser light will continue to be reflected and amplified within the cavity 20, and only a small amount of laser light will be output. Thus, enough energy can be accumulated in the cavity by the laser to achieve higher power in the cavity, and for some application scenes (such as laser-induced breakdown spectroscopy) requiring high power density, the setting of low transmittance can achieve higher energy gain in the cavity. While higher transmittance allows more laser output, it is suitable for some scenes where the output power requirement is not particularly high, but a laser of a certain intensity is required to be directly used for external applications (e.g., laser display, etc.).
In the embodiment of the present invention, the measurement module 30 includes a CCD camera, which is a digital camera using a Charge-Coupled Device (CCD) as a photosensitive element, and an array is formed by a plurality of regularly arranged MOS capacitors. When light irradiates the CCD, photon energy is absorbed by the semiconductor to generate electron-hole pairs, electrons are collected in the capacitor by the electric field to form charge packets, and the charge quantity is proportional to the intensity of incident light. Under the control of an external circuit, the charge packets are sequentially transferred and read out according to a certain sequence, and charge signals are converted into digital signals through an analog-to-digital converter, so that an image is finally formed.
Specifically, the CCD camera is placed close to the output mirror 23, and the spot radius size of the output laser light at the position of the output mirror 23 can be measured in real time.
In the embodiment of the present invention, the displacement control module 40 includes an electric displacement platform controller 42 and a high-precision electric displacement platform 41, where the electric displacement platform controller 42 is electrically connected to the high-precision electric displacement platform 41 and the measurement module 30, respectively, and the input mirror 21 and the output mirror 23 are both fixed on the high-precision electric displacement platform 41.
With continued reference to fig. 2, the device 100 for automatically adjusting the mode ratio of a solid laser provided by the embodiment of the invention adjusts the mode ratio of the solid laser by using the pump light emitted from the pump source 11 to enter the laser crystal 22 through the coupling lens group 13, wherein the spot radius of the pump light entering the laser crystal 22 can be controlled by the coupling lens group 13, the output laser generated by the laser crystal 22 is emitted through the output mirror 23, the spot radius of the output laser is measured by a CCD camera closely attached to the output mirror 23, the equivalent radius of curvature of the input mirror 21 and the required adjusted length of the resonant cavity 20 are obtained according to the theory of the resonant cavity 20, and finally, the length of the resonant cavity 20 is adjusted by using the electric displacement platform to control the spot radius of the output laser in the laser crystal 22, thereby achieving the purpose of automatically adjusting the mode ratio of the solid laser under different pump powers.
Referring to fig. 1 to 3, the present invention further provides a method for automatically adjusting the mode ratio of a solid laser by using the device 100 for automatically adjusting the mode ratio of a solid laser according to any one of the above embodiments, according to the method for automatically adjusting the mode ratio of a solid laser, based on the theory of the laser resonant cavity 20, the size of the spot radius of the output laser at the position of the output mirror 23 is measured by using a CCD camera under different pumping powers, and the equivalent radius of curvature of the output mirror 23 is obtained by calculation, and then the length of the resonant cavity 20 conforming to the preset mode ratio is obtained by calculation, and the length of the resonant cavity 20 between the input mirror 21 and the output mirror 23 is changed by using a high-precision displacement platform, so as to control the size of the spot radius of the output laser in the laser crystal 22, thereby finally achieving the purpose of automatically adjusting the mode ratio of the solid laser under different pumping powers. The adjusting method for automatically adjusting the mode ratio of the solid laser comprises the following steps:
S10, the apparatus 100 for automatically adjusting the mode ratio of the solid-state laser is provided, and the pumping power of the pumping module 10 and the preset mode ratio are determined.
Specifically, the step S10 further includes:
first, an apparatus 100 for automatically adjusting the mode ratio of the solid state laser is provided, the laser crystal 22 is placed against the position of the input mirror 21, and then the pump source 11 is turned on to determine the pump power and the preset mode ratio of the pump module 10.
Specifically, the relation among the preset mode ratio, the spot radius of the output laser light in the laser crystal 22, and the spot radius of the pump light in the laser crystal 22 satisfies the following formula (1):
(1);
Where r is a preset mode ratio, ω l is a spot radius of the output laser light in the laser crystal 22, and ω p is a spot radius of the pump light in the laser crystal 22.
Further, since the pump light enters the laser crystal 22 by being shaped by the coupling lens group 13, the spot radius ω p of the pump light in the laser crystal 22 can be controlled by the coupling lens group 13 and can be set to a constant value.
S20, measuring the spot radius of the output laser at the position of the output mirror 23 under the current pumping power and the initial cavity length corresponding to the resonant cavity 20 at the moment by the measuring module 30 to obtain test data.
Specifically, the step S20 further includes:
First, the spot radius of the output laser light at the position of the output mirror 23 at the current pumping efficiency is measured by a CCD camera and denoted as ω, and the distance between the input mirror 21 and the output mirror 23 at this time, i.e., the initial cavity length of the resonant cavity 20, is measured and denoted as L cav.
S30, the displacement control module 40 adjusts the cavity length of the resonant cavity 20 according to the preset mode ratio and the test data so that the absolute value of the difference between the actual mode ratio of the solid laser and the preset mode ratio is smaller than or equal to 0.01.
Specifically, the step S30 specifically includes:
S301, calculating to obtain the equivalent curvature radius of the input mirror 21 according to the initial cavity length, the curvature radius of the output mirror 23, the wavelength of the output laser and the spot radius of the output laser at the position of the output mirror 23 under the current pumping power.
Specifically, in step S301, the calculation formula (2) of the equivalent radius of curvature of the input mirror 21 is as follows:
(2);
Where R' is the equivalent radius of curvature of the input mirror 21, L cav is the initial cavity length, R 2 is the radius of curvature of the output mirror 23, λ is the wavelength of the output laser, and ω is the spot radius of the output laser at the position of the output mirror 23 at the current pump power.
Further, the calculation formula (2) of the equivalent radius of curvature R 'of the input mirror 21 is derived from the theory of the laser resonator 20, and when the pump power is selected and the spot radius ω of the output laser at the position of the output mirror 23 and the initial cavity length L cav of the resonator 20 are measured, the equivalent radius of curvature R' of the input mirror 21 can be calculated, and the specific derivation process is as follows:
According to the theory of the laser resonator 20, the spot radius size ω of the output laser light at the position of the output mirror 23 can be expressed as follows formula (4):
(4);
the calculation formula for the equivalent radius of curvature R' of the input mirror 21 can be derived from the above formula:
(2)。
S302, calculating according to the preset mode ratio, the spot radius of the pump light in the laser crystal 22, the equivalent curvature radius of the input mirror 21, the curvature radius of the output mirror 23 and the wavelength of the output laser to obtain the target cavity length according with the preset mode ratio.
Specifically, in step S302, the calculation formula (3) of the target cavity length is as follows:
(3);
Where L cav' is the target cavity length, r is the preset mode ratio, ω p is the spot radius of the pump light in the laser crystal 22.
Since the laser crystal 22 is closely attached to the input mirror 21, the spot radius of the output laser in the laser crystal 22 can be approximately equal to the spot radius of the output laser at the position of the input mirror 21, and according to the theory of the laser resonant cavity 20 and the definition of the laser mode ratio, the spot radius ω l of the output laser at the position of the input mirror 21 can be expressed as follows in the following formula (5):
(5);
The target cavity length L cav' according to the preset mode ratio can be derived from the formula (5):
(3)。
S303, the displacement control module 40 controls the high-precision electric displacement platform 41 to adjust the cavity length of the resonant cavity 20 from the initial cavity length to the target cavity length.
Specifically, the target cavity length is substituted into the formula (5), the spot radius omega l of the output laser in the laser crystal 22 can be calculated, and then the actual mode ratio of the solid laser can be calculated according to the formula (1), at the moment, the absolute value of the difference value between the actual mode ratio and the preset mode ratio is smaller than or equal to 0.01, which means that the control precision of the automatic solid laser mode ratio adjusting method is high, and the solid laser mode ratio can be quickly and accurately adjusted according to requirements.
S304, changing the pumping power, repeating the steps S10 to S30, automatically calculating and adjusting the length of the resonant cavity 20 according to different pumping powers, controlling the spot radius omega l of the output laser in the laser crystal 22, and further completing the adjustment of the mode ratio of the solid laser.
The technical scheme of the present invention will now be described with reference to specific embodiments.
Example 1:
Referring to fig. 1 to 3, embodiment 1 of the present invention first provides an apparatus 100 for automatically adjusting a mode ratio of a solid-state laser, comprising:
a pump module 10 for generating pump light and coupling into the resonant cavity 20;
the resonant cavity 20 is optically connected with the pumping module 10 and comprises an input mirror 21, a laser crystal 22 and an output mirror 23 which are sequentially optically connected, and the incident end face of the laser crystal 22 is tightly attached to the input mirror 21;
The measuring module 30 is arranged close to the emergent end face of the output mirror 23 and is used for measuring the spot radius of the output laser at the position of the output mirror 23 and the cavity length of the resonant cavity 20 to obtain test data;
The displacement control module 40 is electrically connected to the measurement module 30, and is configured to adjust the cavity length of the resonant cavity 20 according to the preset mode ratio and the measurement data of the solid-state laser, so that the absolute value of the difference between the actual mode ratio and the preset mode ratio of the solid-state laser is less than or equal to 0.01.
In embodiment 1 of the present invention, the pump module 10 is disposed near the incident side of the input mirror 21, the pump module 10 includes a pump source 11, a transmission fiber 12, and a coupling lens group 13, one end of the transmission fiber 12 is fused with the pump source 11, and the coupling lens group 13 is located between the transmission fiber 12 and the input mirror 21.
Specifically, the pump source 11 is a 808nm laser diode, and the coupling lens group 13 comprises two focusing lenses arranged in parallel with each other. The pump light enters the laser crystal 22 after passing through the coupling lens group 13, and the spot radius omega p of the pump light in the laser crystal 22 is controlled to be 0.2mm through the coupling lens group 13.
Specifically, the input mirror 21 is a concave mirror coated with a 808nm high-transmittance film and a 1053nm high-reflectance film, the radius of curvature of the input mirror 21 is 100mm, the laser crystal 22 is Nd: YLF crystal, the end face size is 3mm×3mm, the crystal length is 10mm, the output mirror 23 is a concave mirror with a transmittance of 15% to 1053nm, the radius of curvature R 2 of the output mirror 23 is 150mm, the transmittance range of the output mirror 23 is 15%, the preset mode ratio R of the solid laser is set to 1, the output laser wavelength λ of the solid laser is 1053nm, and the distance between the input mirror 21 and the output mirror 23, namely the original cavity length L cav of the resonant cavity 20, is measured, and this example 1 is specifically 50mm.
Specifically, the adjusting method for automatically adjusting the mode ratio of the solid-state laser according to the embodiment 1 of the present invention specifically includes the following steps:
Step one, setting the initial power of the pump source 11 to 10W and turning on the pump source 11;
measuring the spot radius omega of the output laser at the position of the output mirror 23 by using a CCD camera to be 172 mu m;
Step three, according to the theory of the laser resonant cavity 20, calculating according to the formula (2) to obtain the equivalent radius of curvature R 'of the input mirror 21, wherein in the embodiment 1, the radius of curvature R' is specifically 53mm;
Step four, calculating to obtain a target cavity length which accords with the set laser mode ratio according to the preset mode ratio R set by the solid laser and the equivalent curvature radius R 'of the input mirror 21, and marking the target cavity length as L cav', wherein the example is specifically 47mm;
step five, adjusting the distance between the input mirror 21 and the output mirror 23 through the electric displacement platform controller 42 and the high-precision displacement platform 41, namely adjusting the cavity length of the resonant cavity 20 to be 47mm;
Step six, calculating the spot radius omega l of the output laser in the laser crystal 22 according to the formula (5), wherein the specific example 1 is 202 μm;
step seven, calculating the actual mode ratio r' of the solid laser to be 1.01 according to the formula (1), wherein the absolute value of the difference between the actual mode ratio and the preset mode ratio is smaller than or equal to 0.01;
Step eight, changing the pumping power, repeating the steps one to seven, thereby realizing automatic calculation and adjustment of the length of the resonant cavity 20 according to different pumping powers, further controlling the spot radius omega l of the output laser in the laser crystal 22, and finally completing adjustment of the mode ratio of the solid laser.
In summary, unlike the prior art, the device 100 for automatically adjusting the mode ratio of the solid laser and the adjusting method thereof provided by the invention are based on the theory of the laser resonant cavity 20, the equivalent curvature radius of the input mirror 21 and the length of the resonant cavity 20 conforming to the set mode ratio of the laser are calculated by measuring the spot radius of the output laser at the position of the output mirror 23, and the length of the resonant cavity 20 is adjusted by the electric displacement platform to control the spot radius of the output laser in the laser crystal 22, so that the mode ratio of the solid laser is adjusted. The device 100 for automatically adjusting the mode ratio of the solid laser has the advantages of simple structure, stability, reliability, high control precision and capability of quickly and accurately adjusting the mode ratio of the solid laser according to requirements.
It should be noted that, the foregoing embodiments all belong to the same inventive concept, and the descriptions of the embodiments have emphasis, and where the descriptions of the individual embodiments are not exhaustive, reference may be made to the descriptions of the other embodiments.
The foregoing examples merely illustrate embodiments of the invention and are described in more detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.
Claims (10)
1. An apparatus for automatically adjusting a mode ratio of a solid state laser, comprising:
the pumping module is used for generating pumping light and coupling the pumping light into the resonant cavity;
the resonant cavity is optically connected with the pumping module and comprises an input mirror, a laser crystal and an output mirror which are sequentially optically connected, and the incident end face of the laser crystal is tightly attached to the input mirror;
The measuring module is closely attached to the emergent end face of the output mirror and is used for measuring the spot radius of the output laser at the position of the output mirror and the cavity length of the resonant cavity to obtain test data;
And the displacement control module is electrically connected with the measurement module and is used for adjusting the cavity length of the resonant cavity according to the preset mode ratio of the solid laser and the measurement data so that the absolute value of the difference value between the actual mode ratio of the solid laser and the preset mode ratio is smaller than or equal to 0.01.
2. The apparatus for automatically adjusting a mode ratio of a solid state laser of claim 1, wherein the pump module is disposed near an incident side of the input mirror, the pump module comprising a pump source, a transmission fiber, and a coupling lens group;
one end of the transmission optical fiber is welded with the pump source, and the coupling lens group is positioned between the transmission optical fiber and the input mirror.
3. The apparatus of claim 2, wherein the pump source is a laser diode and the coupling lens group comprises two focusing lenses arranged parallel to each other.
4. The device for automatically adjusting the mode ratio of the solid laser according to claim 1, wherein the input mirror is a concave mirror, an incident plane of the input mirror is coated with a pumping light antireflection film, an emergent concave surface of the input mirror is coated with a laser high reflection film, the laser high reflection film is used for reflecting output laser excited and output by the laser crystal, the output mirror is a concave mirror, and the transmittance of the output mirror to the output laser is 2% -30%.
5. The apparatus for automatically adjusting a mode ratio of a solid state laser of claim 1, wherein the laser crystal comprises a rare earth doped laser crystal and the measurement module comprises a CCD camera.
6. The apparatus for automatically adjusting a mode ratio of a solid state laser according to claim 1, wherein the displacement control module comprises an electric displacement platform controller and a high-precision electric displacement platform, the electric displacement platform controller is electrically connected with the high-precision electric displacement platform and the measurement module, respectively, and the input mirror and the output mirror are both fixed on the high-precision displacement platform.
7. An adjustment method for automatically adjusting the mode ratio of a solid-state laser using the apparatus for automatically adjusting the mode ratio of a solid-state laser according to any one of claims 1 to 6, the adjustment method comprising:
s10, providing the device for automatically adjusting the mode ratio of the solid laser, and determining the pumping power of the pumping module and the preset mode ratio;
S20, measuring the spot radius of the output laser at the position of the output mirror under the current pumping power and the initial cavity length corresponding to the resonant cavity at the moment by the measuring module to obtain the test data;
And S30, the displacement control module adjusts the cavity length of the resonant cavity according to the preset mode ratio and the test data so that the absolute value of the difference between the actual mode ratio of the solid laser and the preset mode ratio is smaller than or equal to 0.01.
8. The method for automatically adjusting the mode ratio of a solid-state laser according to claim 7, wherein the step S30 specifically comprises:
S301, calculating to obtain the equivalent curvature radius of the input mirror according to the initial cavity length, the curvature radius of the output mirror, the wavelength of the output laser and the spot radius of the output laser at the position of the output mirror under the current pumping power;
s302, calculating according to the preset mode ratio, the spot radius of the pump light in the laser crystal, the equivalent curvature radius of the input mirror, the curvature radius of the output mirror and the wavelength of the output laser to obtain a target cavity length conforming to the preset mode ratio;
S303, the displacement control module controls the high-precision electric displacement platform to adjust the cavity length of the resonant cavity from the initial cavity length to the target cavity length.
9. The method according to claim 8, wherein in the step S301, the calculation formula of the equivalent radius of curvature of the input mirror is as follows:
;
Wherein, R' is the equivalent radius of curvature of the input mirror, L cav is the initial cavity length, R 2 is the radius of curvature of the output mirror, λ is the wavelength of the output laser, and ω is the spot radius of the output laser at the position of the output mirror at the current pumping power.
10. The method according to claim 9, wherein in the step S302, the calculation formula of the target cavity length is as follows:
;
Wherein L cav' is the target cavity length, r is the preset mode ratio, ω p is the spot radius of the pump light in the laser crystal.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6320889B1 (en) * | 1999-08-17 | 2001-11-20 | Jds Uniphase Corporation | Solid state laser including a single mode gain swept configuration |
| CN103794977A (en) * | 2014-01-23 | 2014-05-14 | 中国电子科技集团公司第十一研究所 | Passive mode-locking laser with tunable pulse width |
| CN112345209A (en) * | 2020-09-07 | 2021-02-09 | 武汉光谷航天三江激光产业技术研究院有限公司 | End-pumped laser crystal thermal focus measuring device and method |
| CN115459038A (en) * | 2022-09-29 | 2022-12-09 | 华中科技大学 | Method and device for generating 639nm and 721nm dual-wavelength laser by blue light pumping |
| CN118783221A (en) * | 2024-09-11 | 2024-10-15 | 中国科学院长春光学精密机械与物理研究所 | A cavity-stabilized disk laser with dynamically adjustable cavity length and a control method thereof |
-
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- 2024-12-17 CN CN202411862781.5A patent/CN119674686B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6320889B1 (en) * | 1999-08-17 | 2001-11-20 | Jds Uniphase Corporation | Solid state laser including a single mode gain swept configuration |
| CN103794977A (en) * | 2014-01-23 | 2014-05-14 | 中国电子科技集团公司第十一研究所 | Passive mode-locking laser with tunable pulse width |
| CN112345209A (en) * | 2020-09-07 | 2021-02-09 | 武汉光谷航天三江激光产业技术研究院有限公司 | End-pumped laser crystal thermal focus measuring device and method |
| CN115459038A (en) * | 2022-09-29 | 2022-12-09 | 华中科技大学 | Method and device for generating 639nm and 721nm dual-wavelength laser by blue light pumping |
| CN118783221A (en) * | 2024-09-11 | 2024-10-15 | 中国科学院长春光学精密机械与物理研究所 | A cavity-stabilized disk laser with dynamically adjustable cavity length and a control method thereof |
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