Q-switched laser
By setting up multiple laser crystal modules in a solid Q-regulating laser, the thermal lens effect is reduced, and high power output is achieved without adding an amplifier, which solves the problem of output power limitation in the prior art and simplifies structure and control.
Patent Information
- Application Number
- CN202421712568.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-19
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-07-19
AI Technical Summary
The existing solid Q-regulating lasers are limited in output power due to thermal lensing effects when outputting high power, and an amplifier is needed to achieve high power output, which increases structural complexity and control difficulty.
By setting up multiple laser crystal modules in the laser, the thermal lensing effect of the single crystal is reduced and high power output is achieved. The specific solution includes setting the first, second and third optical path groups, each of which includes a laser crystal module. Through the combination of a total mirror and a mirror, the laser pulse oscillates the gain in multiple crystal modules, reducing the influence of the thermal lens effect.
It realizes that higher laser output power can be obtained without adding an amplifier, reduces the impact of thermal lensing effect, simplifies structure and control, and improves the performance of the laser.
Smart Images
Figure CN222953527U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lasers, in particular to a Q-switched laser. Background Art
[0002] Solid-state lasers are lasers that use solid laser materials as their working medium. The working medium is activated ions uniformly doped in a crystal or glass serving as a matrix material. Q-switching technology has brought about new breakthroughs in laser development, compressing laser energy into extremely narrow pulses for emission, greatly increasing the peak power of the light source.
[0003] However, during laser operation, energy conversion occurs when the light beam passes through the working medium, causing the temperature to rise, causing thermal deformation of the crystal surface. The density of each part is different, and the refractive index changes to form a thermal lens effect, which limits the output power of the solid-state Q-switched laser with fundamental mode output. Therefore, when high-power output is required, it is usually necessary to add an amplifier to achieve it, making the overall structure more complicated and increasing the difficulty of control. Utility Model Content
[0004] To this end, the technical problem to be solved by the present invention is to overcome the technical difficulty of limiting the output power of the solid Q-switched laser with fundamental mode output due to the thermal lens effect in the prior art, and to provide a Q-switched laser that sets multiple laser crystals to reduce the thermal lens effect of a single crystal and achieve high power output.
[0005] In order to solve the above technical problems, the utility model provides a Q-switched laser, which comprises:
[0006] A first optical path group, the first optical path group comprises an output component, a first laser crystal module and an acousto-optic Q-switch which are coaxially arranged in sequence, the output component being used to output laser pulses;
[0007] A second optical path group, comprising a first total reflection mirror, wherein the first total reflection mirror is used to reflect the laser pulse entering the second optical path group from the first optical path group; the second optical path group also comprises a second laser crystal module, and the second laser crystal module is located on the reflection optical path of the first total reflection mirror;
[0008] The third optical path group includes a second total reflection mirror, which is used to reflect the laser pulse entering the third optical path group from the first optical path group; the third optical path group also includes a third laser crystal module, and the third laser crystal module is located on the reflection optical path of the second total reflection mirror.
[0009] In one embodiment of the present invention, the output component is configured as a first partial reflector, the laser pulse transmitted by the first partial reflector is configured to output laser, and the laser pulse reflected by the first partial reflector enters the first laser crystal module.
[0010] In one embodiment of the utility model, it also includes a second partial reflector, which is coaxial with the first optical path group and the third optical path group, and the second partial reflector is tilted; the second partial reflector is used to reflect at least part of the laser pulse of the first optical path group into the second optical path group, and the second partial reflector is used to pass at least part of the laser pulse of the first optical path group into the third optical path group.
[0011] In one embodiment of the present invention, the angle α between the axis of the first optical path group and the axis of the second optical path group is less than 90°.
[0012] In one embodiment of the present invention, a detection module is further included. The detection module is coaxial with the second optical path group, and the laser pulse of the second optical path group enters the detection module through the second partial reflector.
[0013] In one embodiment of the present invention, surfaces of the first total reflection mirror and the second total reflection mirror for reflecting laser pulses both have curvature.
[0014] In one embodiment of the present invention, the first laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet.
[0015] In one embodiment of the utility model, a first laser pump source is further included, and the pump light output by the first laser pump source is coupled and focused on the first laser crystal module.
[0016] In one embodiment of the present invention, the pumping mode of the first laser pump source is set to end pumping or side pumping.
[0017] In one embodiment of the present invention, the second laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet, and the third laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet.
[0018] The above technical solution of the utility model has the following beneficial effects compared with the prior art:
[0019] The utility model discloses a Q-switched laser, in which multiple groups of laser crystal modules are arranged. Compared with a single laser crystal in an existing laser, the influence of thermal lens effect can be reduced, and it is convenient to use higher-power pump light. The laser pulse oscillates and increases the gain in the laser resonant cavity, and a higher-power laser output can be achieved without the aid of an amplifier. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] In order to make the content of the utility model easier to understand, the utility model is further described in detail according to the specific embodiments of the utility model in combination with the accompanying drawings, wherein:
[0021] Figure 1 It is a structural schematic diagram of a Q-switched laser in the prior art;
[0022] Figure 2 It is a structural schematic diagram of a Q-switched laser in a preferred embodiment of the utility model.
[0023] Explanation of the reference numerals in the specification: 1. First optical path group; 11. First partial reflection mirror; 12. First laser crystal module; 13. Acousto-optic Q-switch; 2. Second optical path group; 21. First total reflection mirror; 22. Second laser crystal module; 3. Third optical path group; 31. Second total reflection mirror; 32. Third laser crystal module; 4. Second partial reflection mirror; 5. Detection module. DETAILED DESCRIPTION
[0024] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.
[0025] Example
[0026] Reference Figure 2 As shown, the utility model provides a Q-switched laser, which includes a first optical path group 1, a second optical path group 2 and a third optical path group 3; the Q-switched laser reduces the thermal lens effect generated by a single laser crystal in the existing Q-switched laser by arranging multiple groups of optical paths and laser crystals in the laser resonant cavity, facilitates the use of higher-power pump light, and can obtain a higher laser output power without adding an amplifier.
[0027] Specifically, refer to Figure 2 As shown, the first optical path group 1 includes an output component, a first laser crystal module 12 and an acousto-optic Q-switched switch 13 which are coaxially arranged in sequence, and the acousto-optic Q-switched switch 13 is used to adjust the Q value in the resonant cavity to control the pulse width and repetition rate of the laser output by the Q-switched laser; the output component is used to output laser pulses; in a preferred embodiment of the utility model, the output component is configured as a first partial reflector 11, which partially transmits the laser and partially reflects it, and the laser that transmits the first partial reflector 11 is used for laser power output, and the laser reflected by the first partial reflector 11 enters the first laser crystal module 12, and returns to the resonant cavity to continue to oscillate to form a positive gain.
[0028] Next, the first laser crystal module 12 is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet; the first optical path group 1 also includes a first pump source (not shown in the figure), and the pump light output by the first laser pump source acts on the first laser crystal module 12 after being collimated and focused. The pumping mode of the first laser pump source is configured as end pumping or side pumping. In some embodiments, the pump light pumps the first laser crystal module 12 from the side; in some embodiments, the pump light directly irradiates the first laser crystal module 12 from the end face, and the end face is stimulated to emit photons; the first laser crystal module 12 emits laser after absorbing the pump light of the first pump source.
[0029] It should be noted that, refer to Figure 1 The figure shows the existing Q-switched laser structure, which only has one laser crystal module, and the laser emitted by it oscillates between the reflectors and is directly output after reflection; the laser crystal module is affected by the thermal effect and the output power is limited. Figure 2 As shown, the Q-switched laser described in the utility model also includes a second optical path group 2 and a third optical path group 3, and the second optical path group 2 and the third optical path group 3 are both provided with laser crystal modules. The utility model reduces the influence of the thermal lens effect through the three laser crystals in the resonant cavity, and can use a higher pump power, thereby obtaining a higher laser output power.
[0030] Specifically, refer to Figure 2 As shown, the second optical path group 2 includes a second laser crystal module 22, and the third optical path group 3 includes a third laser crystal module 32; a second partial reflector 4 is provided between the first optical path group 1 and the second optical path group 2 and the third optical path group 3, and a portion of the laser pulse of the first optical path group 1 is reflected by the second partial reflector 4 and enters the second optical path group 2, and enters the second laser crystal module 22 to be amplified, and another portion passes through the second partial reflector 4 and enters the third optical path group 3, and enters the third laser crystal module 32 to be amplified. Since the arm lengths of the second laser crystal and the third laser crystal are different, the Q-switched laser can also generate frequency multiplication, and the frequency is higher than that of the existing Q-switched laser.
[0031] Continue, refer to Figure 2 As shown, the second partial reflector 4 is placed obliquely to enable the laser to be reflected into the second optical path group 2. Preferably, the angle α between the axis of the first optical path group 1 and the axis of the second optical path group 2 is less than 90°. The second partial reflector 4 is placed coaxially with the first optical path group 1 and the third optical path group 3 to enable the laser to be transmitted into the second optical path group 2.
[0032] Next, the second laser crystal module 22 is set to be a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet, and the third laser crystal module 32 is set to be a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet; the second optical path group 2 and the third optical path group 3 both include a pump source (not shown in the figure), and the pumping mode of the pump source can be set to end pumping or side pumping. The second laser crystal module 22 and the third laser crystal module 32 both absorb the pump light of the pump source and emit laser, and are used to perform positive gain amplification on the laser.
[0033] Further, refer to Figure 2 As shown, the second optical path group 2 also includes a first total reflection mirror 21, which is used to reflect the laser pulse in the second optical path group 2. The second laser crystal module 22 is located on the reflection light path of the first total reflection mirror 21. The reflected laser passes through the second laser crystal module 22 and the second partial reflection mirror 4 in turn and returns to the first optical path group 1 to be output or continue to oscillate in the resonant cavity.
[0034] Further, refer to Figure 2 As shown, the third optical path group 3 also includes a second total reflection mirror 31, which is used to reflect the laser pulse in the third optical path group 3. The third laser crystal module 32 is located on the reflection light path of the second total reflection mirror 31, and the reflected laser passes through the third laser crystal module 32 and the second partial reflection mirror 4 in turn and returns to the first optical path group 1 to be output or continue to oscillate in the resonant cavity.
[0035] Next, the reflection surfaces of the first total reflection mirror 21 and the second total reflection mirror 31 for reflecting laser pulses both have a certain curvature, and the spot size of the laser in the resonant cavity is controlled by setting the curvature.
[0036] Specifically, refer to Figure 2 As shown, the Q-switched laser further includes a detection module 5, which is coaxial with the second optical path group 2 and is located on the side of the second partial reflector 4 away from the second optical path group 2; the laser reflected by the first total reflector 21 in the second optical path group 2 can enter the detection module 5 through the second partial reflector 4, and the laser reflected by the second total reflector 31 in the third optical path group 3 can enter the detection module 5 through the reflection of the second partial reflector 4. The detection module 5 is used to detect whether the laser power and pulse are abnormal, to achieve online protection for the Q-switched laser and extend its service life.
[0037] The working principle of the Q-switched laser described in the utility model is as follows:
[0038] In the initial state, the acousto-optic Q-switching switch 13 is turned on, the loss in the resonant cavity increases, and the Q value in the cavity decreases; the first laser crystal module 12, the second laser crystal module 22 and the third laser crystal module 32 absorb pump light to work and accumulate the number of upper energy level particles. When the accumulation of the number of upper energy level particles is completed, the acousto-optic Q-switching switch 13 is turned off. At this time, the Q value of the laser increases in vain, the gain in the resonant cavity is greater than the loss, and a pulse is formed. The formed pulse part is output through the first partial reflector 11, and the other part enters the second optical path group 2 and the third optical path group 3 through the second partial reflector 4, and is amplified in the second laser crystal module 22 and the third laser crystal module 32.
[0039] The pulse amplified by the second laser crystal module 22 is reflected by the first total reflection mirror 21 in the second optical path group 2, and is amplified again by the second laser crystal module 22 after reflection; the pulse amplified by the third laser crystal module 32 is reflected by the second total reflection mirror 31 in the third optical path group 3, and is amplified again by the third laser crystal module 32 after reflection.
[0040] A part of the laser pulse oscillating and amplified in the second optical path group 2 and the third optical path group 3 enters the first optical path group 1 through the second partial reflector 4 for amplification and is then output by the first partial reflector 11, and the other part enters the detection module 5 through the second partial reflector 4 for online detection to avoid abnormalities.
[0041] Obviously, the above embodiments are merely examples for the purpose of clear explanation and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.
Claims
1. A Q-switched laser, characterized in that: include, A first optical path group, the first optical path group comprises an output component, a first laser crystal module and an acousto-optic Q-switch which are coaxially arranged in sequence, the output component being used to output laser pulses; A second optical path group, comprising a first total reflection mirror, wherein the first total reflection mirror is used to reflect the laser pulse entering the second optical path group from the first optical path group; the second optical path group also comprises a second laser crystal module, and the second laser crystal module is located on the reflection optical path of the first total reflection mirror; The third optical path group includes a second total reflection mirror, which is used to reflect the laser pulse entering the third optical path group from the first optical path group; the third optical path group also includes a third laser crystal module, and the third laser crystal module is located on the reflection optical path of the second total reflection mirror.
2. The Q-switched laser according to claim 1, characterized in that: The output component is configured as a first partial reflector, the laser pulse transmitted by the first partial reflector is configured to output laser, and the laser pulse reflected by the first partial reflector enters the first laser crystal module.
3. The Q-switched laser according to claim 1, characterized in that: It also includes a second partial reflector, which is coaxial with the first optical path group and the third optical path group, and the second partial reflector is tilted; the second partial reflector is used to reflect at least part of the laser pulse of the first optical path group into the second optical path group, and the second partial reflector is used to transmit at least part of the laser pulse of the first optical path group into the third optical path group.
4. The Q-switched laser according to claim 3, characterized in that: The angle α between the axis of the first optical path group and the axis of the second optical path group is less than 90°.
5. The Q-switched laser according to claim 3, characterized in that: It also includes a detection module, which is coaxial with the second optical path group, and the laser pulse of the second optical path group enters the detection module through the second partial reflector.
6. The Q-switched laser according to claim 1, characterized in that: The surfaces of the first total reflection mirror and the second total reflection mirror for reflecting laser pulses both have curvature.
7. The Q-switched laser according to claim 1, characterized in that: The first laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet.
8. The Q-switched laser according to claim 7, characterized in that: It also includes a first laser pumping source, and the pumping light output by the first laser pumping source is coupled and focused on the first laser crystal module.
9. The Q-switched laser according to claim 8, characterized in that: The pumping mode of the first laser pumping source is set to end pumping or side pumping.
10. The Q-switched laser according to claim 1, characterized in that: The second laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet, and the third laser crystal module is configured as a neodymium-doped yttrium vanadate crystal or a neodymium-doped yttrium aluminum garnet.