Ultraviolet laser

Abstract

The utility model discloses an ultraviolet laser which comprises a laser generation module, a nonlinear crystal unit, an angle rotation module, an optical power detection module and a control module. The laser generation module is used for generating infrared laser; the nonlinear crystal unit is used for converting part of infrared laser into ultraviolet laser and outputting the ultraviolet laser; the optical power detection module is used for detecting the optical power of the ultraviolet laser and sending the optical power to the control module; the nonlinear crystal unit is located on the surface of one side of the angle rotating module, the angle rotating module is electrically connected with the control module, and the control module is used for controlling the angle rotating module to work according to the optical power so as to drive the nonlinear crystal unit to rotate around the central axis on the first plane and change the phase matching angle of the infrared laser incident to the nonlinear crystal unit; and the optical power reaches the preset optical power. By means of the structure, the light emitting efficiency and the light power output of the ultraviolet laser are improved by changing the phase matching angle, the structure is simple, and the application range is wide.

Description

Technical Field

[0001] The utility model relates to the technical field of lasers, in particular to an ultraviolet laser. Background Art

[0002] Ultraviolet lasers offer advantages such as high precision and high energy density, and are widely used in laser processing, photolithography, and precision measurement. In particular, in the field of semiconductor precision measurement, shorter wavelengths, higher powers, and better beam quality translate into higher measurement accuracy and spatial resolution, resulting in better results. This is thanks to the emergence of laser diode-pumped solid-state lasers and the mature fabrication of nonlinear optical crystals. Currently, lasers used in semiconductor measurement are generally all-solid-state ultraviolet lasers. To achieve high-power ultraviolet laser output, most lasers utilize nonlinear frequency conversion technology. By injecting fundamental frequency light, such as infrared or visible light, into a nonlinear crystal, ultraviolet or even deep ultraviolet laser output can be achieved. In all-solid-state ultraviolet lasers, nonlinear crystals are one of the key components for achieving ultraviolet laser output. The efficiency of generating ultraviolet laser light from fundamental frequency light through nonlinear crystals is affected by factors such as temperature, phase matching angle, and spot size. The higher the efficiency, the higher the ultraviolet light power.

[0003] Currently, most of the ultraviolet lasers on the market control the light output efficiency through temperature, but this method limits the operating temperature of the laser, so that the temperature of the ultraviolet laser can only achieve high-power laser output within a certain range, which greatly limits the application scope of ultraviolet lasers. Utility Model Content

[0004] The utility model provides an ultraviolet laser, which improves the light output efficiency and optical power output of the ultraviolet laser by changing the phase matching angle, has a simple structure and a wide range of applications.

[0005] The utility model provides an ultraviolet laser, comprising a laser generating module, a nonlinear crystal unit, an angle rotation module, an optical power detection module and a control module;

[0006] The laser generation module is used to generate infrared laser;

[0007] The nonlinear crystal unit is used to convert part of the infrared laser into ultraviolet laser and output it;

[0008] The optical power detection module is used to detect the optical power of the ultraviolet laser and send the optical power to the control module;

[0009] The nonlinear crystal unit is located on one side surface of the angle rotation module. The angle rotation module is electrically connected to the control module. The control module is used to control the operation of the angle rotation module according to the optical power, so as to drive the nonlinear crystal unit to rotate around the central axis of the nonlinear crystal unit in the first plane, thereby changing the phase matching angle of the infrared laser incident on the nonlinear crystal unit until the optical power reaches the preset optical power.

[0010] Optionally, the nonlinear crystal unit includes a first nonlinear crystal and a second nonlinear crystal;

[0011] The first nonlinear crystal is located between the laser generating module and the second nonlinear crystal.

[0012] Optionally, the first nonlinear crystal is a frequency doubler crystal.

[0013] Optionally, the second nonlinear crystal is a frequency tripling crystal.

[0014] Optionally, the ultraviolet laser further includes a filter module;

[0015] The filtering module is located between the nonlinear crystal unit and the optical power detection module.

[0016] Optionally, the filtering module is a dichroic mirror.

[0017] Optionally, the UV laser further includes a beam splitter;

[0018] The beam splitter is located between the filter module and the optical power detection module.

[0019] Optionally, the angle rotation module includes a motor and a rotation stage;

[0020] The nonlinear crystal unit is fixed on the rotating platform, and the motor is electrically connected to the rotating platform and the control module respectively.

[0021] Optionally, the optical power detection module is a photodiode.

[0022] The technical solution of the utility model controls the angle rotation module to work when the optical power received by the control module does not reach the preset optical power, so that the angle rotation module drives the nonlinear crystal unit to rotate, changes the phase matching angle of the ultraviolet laser, ensures that the optical power of the ultraviolet laser reaches the preset optical power, improves the light output efficiency of the ultraviolet laser, has a simple structure, and the optical power of the ultraviolet laser is not affected by temperature, and has a wide range of applications.

[0023] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A schematic structural diagram of an ultraviolet laser provided in an embodiment of the present utility model;

[0026] Figure 2 A schematic structural diagram of a second ultraviolet laser provided in an embodiment of the present utility model;

[0027] Figure 3 A schematic structural diagram of the relationship between an angle rotation module, a control module and a nonlinear crystal unit provided in an embodiment of the present utility model;

[0028] Figure 4 This is a schematic structural diagram of a third ultraviolet laser provided in an embodiment of the present utility model. DETAILED DESCRIPTION

[0029] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0030] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0031] In one embodiment, Figure 1 This is a schematic diagram of the structure of an ultraviolet laser provided by an embodiment of the present invention. This embodiment is applicable to situations where a wide range of applications and high optical power output of ultraviolet laser are required. Figure 1 As shown, the ultraviolet laser includes a laser generating module 1, a nonlinear crystal unit 2, an angle rotation module 3, an optical power detection module 4 and a control module 5; the laser generating module 1 is used to generate infrared laser; the nonlinear crystal unit 2 is used to convert part of the infrared laser into ultraviolet laser and output it; the optical power detection module 4 is used to detect the optical power of the ultraviolet laser and send the optical power to the control module 5; the nonlinear crystal unit 2 is located on one side surface of the angle rotation module 3, the angle rotation module 3 is electrically connected to the control module 5, and the control module 5 is used to control the angle rotation module 3 to work according to the optical power, so as to drive the nonlinear crystal unit 2 to rotate around the central axis of the nonlinear crystal unit 2 in the first plane, and change the phase matching angle of the infrared laser incident on the nonlinear crystal unit 2 until the optical power reaches the preset optical power.

[0032] The laser generation module 1 is used to generate infrared laser light. The nonlinear crystal unit 2 in the ultraviolet laser is used to increase or change the frequency of the infrared laser light, thereby obtaining a higher-frequency laser beam. This process is achieved through the nonlinear optical effect. When the infrared laser light passes through a nonlinear optical medium, the electrons in the medium are affected by the laser's electric field, generating new frequency components and achieving laser output at a new wavelength. In this embodiment, the nonlinear crystal unit is used to frequency-double the infrared laser light generated by the laser generation module 1 into ultraviolet laser light for output. The optical power detection module 4 is a structure that detects the optical power of the ultraviolet laser light. In this embodiment, the optical power detection module 4 can be a photodiode. The angle rotation module 3 includes at least a rotating stage, to which the nonlinear crystal unit 2 is fixed. When the angle rotation module 3 is in operation, the rotating stage rotates, thereby driving the nonlinear crystal unit 2 to rotate in a first plane about its central axis, thereby changing the phase matching angle of the infrared laser light incident on the nonlinear crystal unit 2. The first plane is parallel to the rotating stage. The phase matching angle and the optical power of the ultraviolet laser light have a certain relationship, which can be linear or nonlinear. The specific relationship can be determined based on actual conditions and is not limited here. In other words, when the phase-matching angle of nonlinear crystal unit 2 changes, the corresponding optical power of the generated ultraviolet laser will also change accordingly. Control module 5 is the core control module of the ultraviolet laser. It is mainly used to receive the optical power of the ultraviolet laser detected by optical power detection module 4 and control the operation of angle rotation module 3 based on the optical power to change the phase-matching angle, thereby changing the optical power of the ultraviolet laser. When the optical power of the ultraviolet laser reaches the preset optical power, the angle rotation module 3 is controlled to stop operating.

[0033] Specifically, the laser light generated by the laser generation module 1 is transmitted to the nonlinear crystal unit 2. The nonlinear crystal unit 2 performs frequency doubling on a portion of the infrared laser light, converting it into ultraviolet laser light and outputting it. The output ultraviolet laser light is then transmitted to the optical power detection module 4. The optical power detection module 4 detects the optical power of the generated ultraviolet laser light and transmits the detected optical power to the control module 5. After receiving the optical power, the control module 5 compares the optical power with a preset optical power, which can be a maximum optical power. If the optical power does not reach the preset optical power, the control module 5 controls the angle rotation module 3 to rotate the nonlinear crystal unit 2 located on the angle rotation module 3 in a first plane around the central axis of the nonlinear crystal unit 2. This changes the phase matching angle of the infrared laser light incident on the nonlinear crystal unit 2, resulting in a change in the optical power output of the ultraviolet laser light. By changing the phase matching angle of the nonlinear crystal unit 2, the optical power of the ultraviolet laser light is ultimately brought to the preset optical power.

[0034] The technical solution of the embodiment of the utility model controls the angle rotation module to work when the optical power received by the control module does not reach the preset optical power, so that the angle rotation module drives the nonlinear crystal unit to rotate, changes the phase matching angle of the ultraviolet laser, ensures that the optical power of the ultraviolet laser reaches the preset optical power, improves the light output efficiency of the ultraviolet laser, has a simple structure, and the optical power of the ultraviolet laser is not affected by temperature, and has a wide range of applications.

[0035] Optional, Figure 2 The schematic diagram of the structure of the second ultraviolet laser provided by the embodiment of the utility model is shown in FIG. Figure 2 As shown, the nonlinear crystal unit 2 includes a first nonlinear crystal 21 and a second nonlinear crystal 22 ; the first nonlinear crystal 21 is located between the laser generating module 1 and the second nonlinear crystal 22 .

[0036] Optionally, the first nonlinear crystal 21 is a frequency doubler crystal.

[0037] Optionally, the second nonlinear crystal 22 is a frequency tripling crystal.

[0038] Among them, the first nonlinear crystal 21 and the second nonlinear crystal 22 are both frequency doubling crystals, the first nonlinear crystal 21 is a doubled frequency crystal, and the second nonlinear crystal is a tripled frequency crystal. The doubled frequency crystal is mainly used to convert part of the infrared laser frequency doubling into the second harmonic. In this embodiment, the second harmonic is a laser in the green light band. The tripled frequency crystal is used to convert part of the second harmonic and part of the infrared laser frequency doubling into ultraviolet laser light, and output it to the optical power detection module 4. Generally, the materials of the doubled frequency crystal and the tripled frequency crystal can include but are not limited to nonlinear optical crystals such as lithium triborate (LBO), barium metaborate (BBO) or potassium titanyl phosphate (KTP). The specific material can be determined according to actual conditions and is not limited here.

[0039] Specifically, the infrared laser is frequency-doubled and converted into second harmonic after passing through the first nonlinear crystal 21 and sent to the second nonlinear crystal 22. The second nonlinear crystal 22 frequency-doubles and converts part of the infrared laser and part of the second harmonic into ultraviolet laser and outputs it.

[0040] Optional, Figure 3 This is a schematic diagram of the relationship between an angle rotation module, a control module and a nonlinear crystal unit provided by an embodiment of the present invention, with reference to Figure 2 and Figure 3 As shown, the angle rotation module 3 includes a motor 31 and a rotating platform 32 ; the nonlinear crystal unit 2 is fixed on the rotating platform 32 , and the motor 31 is electrically connected to the rotating platform 32 and the control module 5 , respectively.

[0041] When the angle rotation module 3 drives the nonlinear crystal unit 2 to rotate, the angle rotation module 3 typically includes two motors 31 and two rotation stages 32, namely, a first motor 311, a second motor 312, a first rotation stage 321, and a second rotation stage 322. The first nonlinear crystal 21 is fixed to the first rotation stage 321, and the second nonlinear crystal 22 is fixed to the second rotation stage 322. The first motor 311 is electrically connected to the first rotation stage 321 and the control module 5, respectively, and the second motor 312 is electrically connected to the second rotation stage 322 and the control module 5, respectively. When controlling the rotation of the first nonlinear crystal 21, the control module 5 controls the first motor 311 to operate so that the first motor 311 controls the first rotation stage 321 to rotate around the central axis of the first rotation stage 321 in a first plane parallel to the first rotation stage 321, thereby driving the first nonlinear crystal 21 to rotate synchronously around the central axis of the first nonlinear crystal 21, thereby changing a phase matching angle, thereby changing the optical power of the ultraviolet laser. Similarly, when controlling the rotation of the second nonlinear crystal 22, the control module 5 controls the second motor 312 to operate, so that the second motor 312 controls the second rotating stage 322 to rotate around the central axis of the second rotating stage 322 in a first plane parallel to the second rotating stage 322, thereby driving the second nonlinear crystal 22 to synchronously rotate around the central axis of the second nonlinear crystal 22 to change the second type of phase matching angle, thereby changing the optical power of the ultraviolet laser. The operating order of the first rotating stage 321 and the second rotating stage 322 can be determined according to actual conditions. The first rotating stage 321 can be controlled to operate first to change the optical power by changing the first type of phase matching angle so that the optical power of the ultraviolet laser reaches the maximum optical power, and then the second rotating stage 322 can be controlled to operate to change the optical power by changing the second type of phase matching angle so that the optical power of the ultraviolet laser reaches the preset optical power. Similarly, the second rotating stage 322 can be controlled to change the optical power by varying the second phase matching angle, so that the optical power of the ultraviolet laser reaches the maximum optical power. The first rotating stage 321 can then be controlled to change the optical power by varying the first phase matching angle, so that the optical power of the ultraviolet laser reaches a preset optical power, which is typically the maximum optical power. The first and second phase matching angles can also be varied simultaneously until the final optical power of the ultraviolet laser reaches the preset optical power, i.e., the maximum optical power.

[0042] Optional, Figure 4 The schematic diagram of the structure of the third ultraviolet laser provided by the embodiment of the utility model is shown in FIG. Figure 4 As shown, the ultraviolet laser further includes a filter module 6 ; the filter module 6 is located between the nonlinear crystal unit 2 and the optical power detection module 4 .

[0043] Optionally, the filtering module 6 is a dichroic mirror.

[0044] The filter module 6 is used to filter part of the infrared laser and the second harmonic output from the nonlinear crystal unit 2, so that only the ultraviolet laser can be transmitted normally. In this embodiment, the filter module 6 is a dichroic mirror.

[0045] Optional, continue to refer to Figure 4 As shown, the ultraviolet laser further includes a beam splitter 7 ; the beam splitter 7 is located between the filter module 6 and the optical power detection module 4 .

[0046] The beam splitter 7 is used to split the generated ultraviolet laser light, sending a portion to the optical power detection module 4, while the other portion is used normally for ultraviolet laser application. Typically, the ultraviolet laser light sent to the optical power detection module 4 is 1%-5% of the output ultraviolet laser light. The specific amount can be determined according to actual conditions and is not limited here.

[0047] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in this utility model can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of this utility model can be achieved. This is not limited herein.

[0048] The above specific embodiments do not limit the scope of protection of this utility model. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model shall be included within the scope of protection of this utility model.

Claims

1. An ultraviolet laser, characterized in that: It includes a laser generation module, a nonlinear crystal unit, an angle rotation module, an optical power detection module and a control module; The laser generating module is used to generate infrared laser; The nonlinear crystal unit is used to convert part of the infrared laser into ultraviolet laser and output it; The optical power detection module is used to detect the optical power of the ultraviolet laser and send the optical power to the control module; The nonlinear crystal unit is located on a side surface of the angle rotation module. The angle rotation module is electrically connected to the control module. The control module is used to control the operation of the angle rotation module according to the optical power to drive the nonlinear crystal unit to rotate around the central axis of the nonlinear crystal unit in a first plane, thereby changing the phase matching angle of the infrared laser incident on the nonlinear crystal unit until the optical power reaches a preset optical power.

2. The ultraviolet laser according to claim 1, characterized in that The nonlinear crystal unit includes a first nonlinear crystal and a second nonlinear crystal; The first nonlinear crystal is located between the laser generating module and the second nonlinear crystal.

3. The ultraviolet laser according to claim 2, characterized in that: The first nonlinear crystal is a frequency doubler crystal.

4. The ultraviolet laser according to claim 2, characterized in that: The second nonlinear crystal is a frequency tripling crystal.

5. The ultraviolet laser according to claim 1, characterized in that: Also includes filtering module; The filtering module is located between the nonlinear crystal unit and the optical power detection module.

6. The ultraviolet laser according to claim 5, characterized in that: The filtering module is a dichroic mirror.

7. The ultraviolet laser according to claim 5, characterized in that: Also includes beam splitters; The beam splitter is located between the filtering module and the optical power detection module.

8. The ultraviolet laser according to claim 1, characterized in that: The angle rotation module includes a motor and a rotating platform; The nonlinear crystal unit is fixed on the rotating platform, and the motor is electrically connected to the rotating platform and the control module respectively.

9. The ultraviolet laser according to claim 1, characterized in that: The optical power detection module is a photodiode.

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