Light source module and laser processing equipment

Abstract

The embodiment of the invention provides a light source module and laser processing equipment, and relates to the field of optical devices. The light spot quality of the light source module is improved. According to the specific scheme, the light source module comprises a pulse laser, a first nonlinear optical crystal and a second nonlinear optical crystal. The pulse laser is used for outputting laser with the pulse width larger than or equal to 20 ps. The first nonlinear optical crystal is used for receiving laser from the pulse laser and outputting a first light beam after frequency conversion. The second nonlinear optical crystal is used for receiving the first light beam from the first nonlinear optical crystal and then outputting a second light beam, and the central wavelength of the second light beam is larger than that of the first light beam. A light shaping element with the focal length larger than or equal to 80 mm is further arranged in a light path between the first nonlinear optical crystal and the second nonlinear optical crystal. The M2 factor of the light source emitted by the light source module is small, the light beam quality and the light beam energy are high, and the light spot quality is good.

Description

Technical Field

[0001] This application relates to the field of optical devices, and more particularly to a light source module and laser processing equipment. Background Technology

[0002] Laser processing is the most common application of laser systems. The principle of laser processing is to utilize the thermal effect or photochemical reaction generated when a laser beam is projected onto the surface of a material to complete the processing. This includes, but is not limited to, laser welding, laser engraving, laser drilling, and stereolithography. Among these, the laser source is a crucial component of laser processing equipment, and the quality of the laser spot directly affects the processing results.

[0003] Therefore, this application only aims to improve the spot quality of the laser source. Summary of the Invention

[0004] This application provides a light source module and a laser processing equipment, which aim to improve the spot quality of the light source module.

[0005] To achieve the above objectives, this application adopts the following technical solution.

[0006] In a first aspect, this application provides a light source module. The light source module includes a pulsed laser, a first nonlinear optical crystal, and a second nonlinear optical crystal. The pulsed laser is used to output laser light with a pulse width greater than or equal to 20 ps. The first nonlinear optical crystal is used to receive the laser light from the pulsed laser, perform frequency conversion, and output a first beam. The second nonlinear optical crystal is used to receive the first beam from the first nonlinear optical crystal and output a second beam, wherein the center wavelength of the second beam is greater than the center wavelength of the first beam.

[0007] Thus, the second beam obtained after a laser with a pulse width greater than 20 ps passes through the first and second nonlinear optical crystals can significantly improve the beam quality and beam energy. Compared to a laser with a pulse width less than 20 ps, ​​a laser with a pulse width greater than or equal to 20 ps is beneficial for reducing the M² factor of the second beam, thereby improving the beam quality and beam energy.

[0008] In conjunction with the first aspect, in some feasible ways, the pulsed laser is used to output a laser beam with a pulse width greater than or equal to 50 ps. This can further improve the beam quality and beam energy of the second beam.

[0009] In conjunction with the first aspect, in some feasible embodiments, the light source module further includes: a light shaping element. The focal length of the light shaping element is greater than or equal to 80mm. The second nonlinear optical crystal for receiving the first beam from the first nonlinear optical crystal and outputting the second beam includes: the light shaping element for receiving the first beam from the first nonlinear optical crystal, converging the first beam, and then outputting it. The second nonlinear optical crystal for receiving the first beam from the light shaping element and outputting the second beam.

[0010] Thus, with a focal length greater than or equal to 80mm, the conversion efficiency of the second nonlinear optical crystal to the first beam can be improved, and the energy of the center wavelength of the second beam can be increased.

[0011] In conjunction with the first aspect, in some feasible embodiments, the spot diameter of the first beam converged by the light shaping element is greater than or equal to 30 μm. Thus, the larger spot diameter of the first beam transmitted to the second nonlinear optical crystal is beneficial for improving the conversion efficiency of the second nonlinear optical crystal, thereby increasing the energy of the second beam and ultimately improving the efficiency of the light source module.

[0012] In conjunction with the first aspect, in some feasible ways, the diameter of the light spot transmitted from the first beam to the incident surface of the second nonlinear optical crystal is greater than or equal to 30 μm.

[0013] In conjunction with the first aspect, in some feasible embodiments, the light source module further includes a third nonlinear optical crystal. This third nonlinear optical crystal amplifies the second beam from the second nonlinear optical crystal before outputting it. Thus, the third nonlinear optical crystal performs optical parametric amplification of the second beam before outputting it. The third nonlinear optical crystal can further increase the energy of the second beam.

[0014] In conjunction with the first aspect, in some feasible embodiments, the light source module further includes a fourth nonlinear optical crystal. This fourth nonlinear optical crystal amplifies the second beam emitted from the third nonlinear optical crystal before outputting it. Thus, the fourth nonlinear optical crystal can further amplify the second beam, further increasing the power of the beam emitted from the light source module.

[0015] In conjunction with the first aspect, in some feasible implementations, the light source module further includes a seed injection component. This seed injection component is used to output a third beam, and the second nonlinear optical crystal is also used to receive the third beam from the seed injection component and output the second beam; the wavelength band of the third beam and the wavelength band of the second beam at least partially overlap. Thus, the seed injection component can improve the conversion efficiency of the second nonlinear optical crystal. Furthermore, the third beam output by the seed injection component can narrow the wavelength band of the second beam, thus narrowing the spectral width of the second beam.

[0016] In conjunction with the first aspect, in some feasible embodiments, the light source module further includes a reflective element. This reflective element reflects the second beam from the second nonlinear optical crystal back to the second nonlinear optical crystal; the second nonlinear optical crystal also amplifies the second beam from the reflective element before outputting it. Thus, the second nonlinear optical crystal can simultaneously perform the functions of optical parametric generation and optical parametric amplification, increasing the power of the second beam while reducing the number of components in the light source module, and also helping to reduce the size of the light source module.

[0017] In conjunction with the first aspect, in some feasible embodiments, the pulsed laser includes any one of the following: a Yb-doped fiber laser, an Er-doped fiber laser, an Nd-doped fiber laser, a Tm-doped fiber laser, a Yb:YAG solid-state laser, an Nd:YAG solid-state laser, an Nd:YVO4 solid-state laser, or a Ti:sapphire laser. Thus, the aforementioned pulsed lasers can all output lasers with relatively wide pulse widths, produce higher pulsed laser energy, and more easily output high-energy pulsed lasers.

[0018] In conjunction with the first aspect, in some feasible ways, the first nonlinear optical crystal is a frequency doubling crystal.

[0019] In conjunction with the first aspect, in some feasible implementations, the light source module also includes a temperature control component. The temperature control component is used to regulate the temperature of the second nonlinear optical crystal.

[0020] Secondly, embodiments of this application provide a light source module. The light source module includes a pulsed laser, a first nonlinear optical crystal, a second nonlinear optical crystal, and a light shaping element. The pulsed laser is used to output laser light; the first nonlinear optical crystal is used to receive the laser light from the pulsed laser, perform frequency conversion, and output a first beam. The light shaping element is used to receive the first beam from the first nonlinear optical crystal, converge the first beam, and output it; the focal length of the light shaping element is greater than or equal to 80mm. The second nonlinear optical crystal is used to receive the first beam from the light shaping element and output a second beam, wherein the center wavelength of the second beam is greater than the center wavelength of the first beam.

[0021] Thus, in this optical path, the focal length of the optical shaping element is greater than or equal to 80mm, and the spot size of the first beam transmitted to the second nonlinear optical crystal is relatively large. This allows the first beam to enter the second nonlinear optical crystal more uniformly, be fully converted by the second nonlinear optical crystal, improve the conversion efficiency of the second nonlinear optical crystal for the first beam, and improve the energy of the center wavelength of the second beam while also improving the beam quality of the second beam.

[0022] In conjunction with the second aspect, in some feasible ways, the spot diameter of the first beam converged by the light shaping element is greater than or equal to 30 μm.

[0023] In conjunction with the second aspect, in some feasible embodiments, the light source module further includes a third nonlinear optical crystal. This third nonlinear optical crystal is used to amplify the second beam from the second nonlinear optical crystal before outputting it.

[0024] In conjunction with the second aspect, in some feasible embodiments, the light source module further includes a fourth nonlinear optical crystal. This fourth nonlinear optical crystal is used to amplify the second beam from the third nonlinear optical crystal before outputting it.

[0025] In conjunction with the second aspect, in some feasible embodiments, the light source module further includes a seed injection component. The seed injection component is used to output a third beam, and the second nonlinear optical crystal is also used to receive the third beam from the seed injection component; the wavelength of the third beam at least partially overlaps with the wavelength of the second beam.

[0026] In conjunction with the second aspect, in some feasible embodiments, the light source module further includes a reflective element. The reflective element is used to reflect the second beam from the second nonlinear optical crystal back to the second nonlinear optical crystal; the second nonlinear optical crystal is also used to amplify the second beam from the reflective element before outputting it.

[0027] In conjunction with the second aspect, in some feasible embodiments, the pulsed laser includes any one of: a Yb-doped fiber laser, an Er-doped fiber laser, an Nd-doped fiber laser, a Tm-doped fiber laser, a Yb:YAG solid-state laser, an Nd:YAG solid-state laser, an Nd:YVO4 solid-state laser, or a Ti:Sapphire laser.

[0028] In conjunction with the second aspect, in some feasible ways, the first nonlinear optical crystal is a frequency doubling crystal.

[0029] Thirdly, embodiments of this application provide a laser processing apparatus. The laser processing apparatus includes a controller and any one of the light source modules provided in the first or second aspect, the controller being signal-connected to the light source module.

[0030] Regarding the beneficial effects of the second and third aspects, please refer to the description of any optional implementation method in the first aspect, which will not be repeated here. Based on the implementation methods provided in the above aspects, this application can also be further combined to provide more implementation methods. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of a laser processing equipment.

[0032] Figure 2 This is a schematic diagram of the structure of a light source module provided in an embodiment of this application.

[0033] Figure 3 This is a schematic diagram of another light source module provided in an embodiment of this application.

[0034] Figure 4 This is a schematic diagram of another light source module provided in an embodiment of this application.

[0035] Figure 5 This is a schematic diagram of another light source module provided in an embodiment of this application.

[0036] Figure 6 This is a schematic diagram of another light source module provided in an embodiment of this application.

[0037] Figure 7 This is a schematic diagram of the structure of a light source module including a seed injection component, provided for an embodiment of this application.

[0038] In the diagram: 10-Laser processing equipment; 100-Light source module; 20-Lens assembly; 30-Clamping mechanism; 31-Workpiece; 110-First nonlinear optical crystal; 120-Second nonlinear optical crystal; 130-Third nonlinear optical crystal; 140-Fourth nonlinear optical crystal; 150-Reflective element; 160-Seed injection assembly; 210-Pulsed laser; 220-Optical shaping element; g1-Laser; g2-First beam; g3-Second beam; g4- Third beam; 201-First polarizer; 202-First focusing lens; 203-Second focusing lens; 204-First wave splitter; 205-First reflecting mirror; 206-Second reflecting mirror; 207-Second polarizer; 208-Third focusing lens; 209-Third polarizer; 211-First isolator; 212-Third wave splitter; 213-Second isolator; 214-Second wave splitter; 215-Third reflecting mirror; 216-Fourth wave splitter; 217-Fourth focusing lens. Detailed Implementation

[0039] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0040] Hereinafter, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature.

[0041] Furthermore, in the embodiments of this application, directional terms such as "up," "down," "left," "right," "horizontal," and "vertical" are defined relative to the orientation of the components shown in the accompanying drawings. It should be understood that these directional terms are relative concepts, used for relative description and clarification, and can change accordingly depending on the orientation of the components in the accompanying drawings.

[0042] In the embodiments of this application, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, "connection" can be a fixed connection, an electrical connection, a detachable connection, or an integral part; it can be a direct connection or an indirect connection through an intermediate medium.

[0043] Figure 1 This is a schematic diagram of the structure of a laser processing device 10. Please refer to [link / reference]. Figure 1 The laser processing equipment 10 includes a lens assembly 20 and a light source module 100. The lens assembly 20 is used to receive the light beam from the light source module 100.

[0044] In some embodiments, the lens assembly 20 shapes the light beam from the light source module 100. For example, the lens assembly 20 includes a focusing lens or a wave splitter.

[0045] In some embodiments, the lens assembly 20 is used to change the transmission direction of the light beam from the light source module 100. For example, the lens assembly 20 includes a reflector, etc.

[0046] For example, the lens assembly 20 may include devices such as a spatial light modulator (SLM), a diffractive optical element (DOE), or a metasurface.

[0047] In some embodiments, the laser processing equipment 10 may also include devices such as acousto-optical modulators (AOM) or electro-optic modulators (EOM) for controlling the rapid on / off switching of the beam.

[0048] In some embodiments of this application, the laser processing equipment 10 may further include a clamping mechanism 30 for clamping the workpiece 31. The lens assembly 20 is used to project the light beam from the light source module 100 onto the workpiece 31.

[0049] This application does not limit the application scenarios of the laser processing equipment 10. For example, the laser processing equipment 10 can be used for laser cutting, laser etching, laser engraving, laser drilling, laser scribing, laser welding, or laser heat treatment.

[0050] The material of the workpiece processed by the laser processing equipment 10 can be, for example, glass, Si, GaN, SiC, sapphire, etc. This application embodiment does not impose any limitations on this.

[0051] Figure 2 This is a schematic diagram of the structure of a light source module 100 provided in an embodiment of this application. Please refer to... Figure 2 The light source module 100 includes a pulsed laser 210, a first nonlinear optical crystal 110, and a second nonlinear optical crystal 120. The pulsed laser 210 outputs a laser beam g1 with a pulse width greater than or equal to 20 picoseconds (ps). The first nonlinear optical crystal 110 receives the laser beam g1 from the pulsed laser 210, performs frequency conversion, and outputs a first beam g2. The second nonlinear optical crystal 120 receives the first beam g2 from the first nonlinear optical crystal 110 and outputs a second beam g3, wherein the center wavelength of the second beam g3 is greater than the center wavelength of the first beam g2. Thus, the laser beam g1 output by the pulsed laser 210 passes through the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120 to obtain the second beam g3.

[0052] Current theories do not reveal a relationship between the pulse width of the laser output and the spot quality of the second beam g3. Furthermore, current theories do not reveal any relationship between the spot quality of the second beam g3 obtained after the laser output passes sequentially through the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120 and the pulse width of the laser output.

[0053] In the embodiments of this application, the second beam g3 obtained by passing a laser with a pulse width greater than 20 ps through the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120 can significantly improve the spot quality and beam energy of the second beam g3.

[0054] Compared to a laser pulse width of less than 20 ps, ​​the laser pulse width of 20 ps or more in this embodiment is advantageous in reducing the M2 factor of the second beam g3, thereby improving the beam quality of the second beam g3. The aforementioned M2 factor is a parameter used to quantify the beam quality of a laser beam. A laser pulse width of 20 ps or more also helps to increase the beam energy of the second beam g3.

[0055] The pulse width of laser g1 refers to the duration for which the laser power is maintained at a certain value.

[0056] In the embodiments of this application, the nonlinear optical crystal is a crystal that exhibits second-order or higher nonlinear optical effects in response to strong electric fields from lasers.

[0057] In some embodiments of this application, the pulsed laser 210 is used to output a laser g1 with a pulse width greater than 50 ps. This can further improve the beam quality and increase the beam energy of the second beam g3. For example, the pulse width of the laser g1 can be 20 ps, ​​30 ps, ​​40 ps, ​​50 ps, ​​60 ps, ​​70 ps, ​​80 ps, ​​100 ps, ​​120 ps, ​​130 ps, ​​150 ps, ​​180 ps, ​​200 ps, ​​216 ps, 240 ps, ​​252 ps, 300 ps, ​​1 ns (nanosecond), 2 ns, 5 ns, 10 ns, or 20 ns, etc.

[0058] For example, in embodiments where the pulse width of laser g1 is greater than 100 ps, ​​the M2 factor of the second beam g3 can be further reduced, and the spot quality can be further improved.

[0059] In embodiments where the pulse width of laser g1 is greater than 200 ps, ​​the spot quality of the second beam g3 can be further improved, and the spot energy can be further increased.

[0060] In the embodiments of this application, the wavelength band of laser g1 is relatively narrow; for example, the wavelength band of laser g1 is ±4 nm (nanometers) of its center wavelength. Similarly, the wavelength band of the first beam g2 is relatively narrow; for example, the wavelength band of the first beam g2 is ±4 nm of its center wavelength. The wavelength band of the second beam g3 is relatively narrow; for example, the wavelength band of the second beam g3 is ±4 nm of its center wavelength.

[0061] In some embodiments, laser g1 can be a narrow linewidth beam, for example, the wavelength of laser g1 is ±1 nm of its center wavelength. Similarly, the wavelength of the first beam g2 is ±1 nm of its center wavelength. The wavelength of the second beam g3 is ±1 nm of its center wavelength.

[0062] It is understood that the embodiments of this application do not limit the first nonlinear optical crystal 110 to emitting only the first beam g2. For example, the first nonlinear optical crystal 110 may also emit stray light with a wavelength different from the first beam g2.

[0063] Similarly, this application embodiment does not limit the second nonlinear optical crystal 120 to only emit the second beam g3. For example, the second nonlinear optical crystal 120 may also emit stray light with a wavelength different from the second beam g3. Furthermore, this application embodiment does not limit the second nonlinear optical crystal 120 to only receive the first beam g2. For example, the second nonlinear optical crystal 120 may receive both the first beam g2 and stray light emitted by the first nonlinear optical crystal 110 with a wavelength different from the first beam g2.

[0064] In some embodiments of this application, the pulsed laser includes any one of the following: a Yb (Ytterbium) doped fiber laser, an Er (erbium) doped fiber laser, an Nd (neodymium) doped fiber laser, a Tm (Thulium) fiber laser, a Yb:YAG solid-state laser, an Nd:YAG solid-state laser, an Nd:YVO4 solid-state laser, or a Ti:Sapphire laser.

[0065] Yb-doped fiber lasers are used to generate lasers with a center wavelength of 1030 nm. Erbium-doped fiber lasers are used to generate lasers with a center wavelength of 1550 nm.

[0066] The chemical formula for YAG is Y3Al5O 12 Yb:YAG is a composite oxide formed by the reaction of Y₂O₃ and Al₂O₃. It belongs to the cubic crystal system and has a garnet structure. Yb:YAG solid-state lasers, also known as yttrium aluminum garnet lasers, are used to generate lasers with a center wavelength of 1030 nm.

[0067] Nd:YAG is a neodymium-doped yttrium aluminum garnet crystal used to generate lasers with a center wavelength of 1064 nm. Nd:YVO4 is a neodymium-doped yttrium vanadate crystal.

[0068] Among them, Yb-doped fiber lasers, Yb:YAG solid-state lasers, or Nd:YVO4 solid-state lasers produce pulsed lasers with higher energy and are more likely to output high-energy pulsed lasers.

[0069] For example, the pulse width of the laser output can be adjusted by setting the mode-locked seed source of the laser, so that the pulse width of the laser is greater than or equal to 20 ps. Alternatively, the pulse width of the laser output can be adjusted by modulating the electrical signal input pulse width of the seed source, so that the pulse width of the laser is greater than or equal to 20 ps.

[0070] It is understood that in other embodiments of this application, other lasers capable of outputting pulsed lasers with a pulse width greater than or equal to 20 ps may be used, and the embodiments of this application are not limited to the above-mentioned pulsed lasers.

[0071] As described above, the first nonlinear optical crystal 110 receives laser g1, performs a magnification conversion on laser g1, and outputs a first beam g2.

[0072] In some embodiments of this application, the first nonlinear optical crystal 110 is a frequency-doubling crystal. A frequency-doubling crystal refers to one or more of the following: second-harmonic generation (SHG), third-harmonic generation (THG), sum-frequency generation (SFG), and difference-frequency generation (DFG). A second-harmonic generation crystal has a second harmonic generation (SHG) function, a third-harmonic generation (THG) function, a sum-frequency generation (SFG) function, and a difference-frequency generation (DFG) function. For example, a second-harmonic generation crystal can double the frequency and halve the wavelength, while a third-harmonic generation crystal can double the frequency and reduce the wavelength to one-third of the original wavelength. The input to a sum-frequency generation crystal can be two or more laser beams, and the output laser beam has a frequency equal to the sum of the frequencies of the two or more laser beams. The input to a difference-frequency generation crystal can be two or more laser beams, and the output laser beam has a frequency equal to the difference between the frequencies of the two or more laser beams.

[0073] For example, the material of the first nonlinear optical crystal 110 can be lithium niobate (LiNbO3, abbreviated as LN), lithium tantalate (LiTaO3, abbreviated as LT), potassium dihydrogen phosphate (KH2PO4, abbreviated as KDP), potassium dideuterium phosphate (KD2PO4, abbreviated as DKDP), lithium iodate (LiIO3, abbreviated as LI), potassium titanium oxyphosphate (KTiOPO4, abbreviated as KTP), barium metaborate (BaB2O4, abbreviated as BBO), lithium triborate (LiB3O5, abbreviated as LBO), potassium niobate (KNbO3, abbreviated as KN), cesium borate (CSB3O5, abbreviated as CBO), lithium cesium borate (LiCSB6O3), etc. 10 Yttrium gallium sulfide (YSOB), potassium beryllium fluoroborate (KBe2BO3F2, abbreviated as KBBF), silver gallium sulfide (AgGaS2, abbreviated as AGS), silver gallium selenide (AgGaSe2, abbreviated as AGSe), cadmium germanium arsenide (CdGeAs, abbreviated as CGA), cadmium selenide (CdSe), gallium selenide (GaSe), calcium yttrium borate (YCOB), or zinc germanium phosphate (ZnGeP2, abbreviated as ZGP), etc.

[0074] For example, the crystal length of the first nonlinear optical crystal 110 is 10cm-60cm, such as 10cm, 20cm, 30cm, 40cm, 50cm, or 60cm. This can improve the conversion efficiency of the first nonlinear optical crystal 110.

[0075] In some embodiments of this application, the second nonlinear optical crystal 120 performs optical parametric generation (OPG) on the first beam g2 and then outputs a second beam g3. The material of the second nonlinear optical crystal 120 is described in the aforementioned description of the material of the first nonlinear optical crystal 110, and will not be repeated here.

[0076] In some embodiments of this application, the light source module 100 may further include a temperature control component for adjusting the temperature of the second nonlinear optical crystal 120. This ensures that the second beam g3 output from the second nonlinear optical crystal 120 is phase-matched with the first beam g2 transmitted to the second nonlinear optical crystal 120, which is beneficial for improving the conversion efficiency of the second nonlinear optical crystal 120. The temperature of the second nonlinear optical crystal 120 is designed based on the center wavelength of the second beam g3.

[0077] For example, the crystal length of the second nonlinear optical crystal 120 is 10cm-60cm, such as 10cm, 20cm, 30cm, 40cm, 50cm, or 60cm. This can improve the conversion efficiency of the second nonlinear optical crystal 120.

[0078] In this embodiment, the center wavelength of the laser g1 and the frequency doubling of the first nonlinear optical crystal 110 are not limited, and can be set according to the requirements of the center wavelength of the second beam g3.

[0079] In some embodiments, the pulsed laser 210 is a Yb:YAG laser, the center wavelength of laser g1 is 1030nm, the first nonlinear optical crystal 110 is a frequency-doubled crystal, the center wavelength of the first beam g2 is 515nm, and the center wavelength of the second beam g3 is 780nm.

[0080] In some embodiments, the pulsed laser 210 is a Yb-doped fiber laser, the center wavelength of laser g1 is 1064 nm, and the pulse width of laser g1 is 216 ps. The first nonlinear optical crystal 110 is a frequency-second harmonic crystal, the center wavelength of the first beam g2 is 532 nm, and the center wavelength of the second beam g3 is 790 nm.

[0081] Furthermore, in the embodiments of this application, the second beam g3 can be visible light. For example, the center wavelength of the second beam g3 can be in the range of 400-760nm. The visible light band has significant performance advantages for material processing. In addition, the wavelength of the second beam g3 can be flexibly adjusted by adjusting the temperature of the second nonlinear optical crystal 120, thereby obtaining high-energy visible light with flexible band adjustment. For example, by adjusting the pulse width of the laser emitted by the pulsed laser 210 to be greater than or equal to 20ps, the pulsed laser energy generated by the light source module 100 at 780nm is one order of magnitude higher than that of the prior art.

[0082] The embodiments of this application do not limit the extension path of the optical path in the light source module 100, and can be set according to the shape and size of the light source module 100.

[0083] like Figure 2 As shown, in some embodiments of this application, the light source module 100 may further include multiple lenses, which are located in the optical path of the light source module 100.

[0084] Figure 2 In this light source module 100, there may also be an optical shaping element 220. The focal length of the optical shaping element 220 is greater than or equal to 80mm. The optical shaping element 220 is located in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120.

[0085] For example, the optical shaping element 220 receives a first beam g2 from the first nonlinear optical crystal 110, and outputs the first beam g2 after focusing it. The second nonlinear optical crystal 120 receives the first beam g2 from the optical shaping element 220 and outputs a second beam g3. The first beam g2 is focused by the optical shaping element 220 and then transmitted to the second nonlinear optical crystal 120. The second nonlinear optical crystal 120 performs optical parametric generation on the focused first beam g2 to output the second beam g3. The focal length of the optical shaping element 220 is greater than or equal to 80mm, which can improve the conversion efficiency of the second nonlinear optical crystal 120 for the first beam g2 and increase the energy of the center wavelength of the second beam g3.

[0086] The conversion efficiency of the second nonlinear optical crystal 120 to the first beam g2 refers to the percentage of the energy of the second beam g3 to the energy of the first beam g2. The rest of the descriptions of conversion efficiency in the text follow the same logic.

[0087] Compared to the focal length of the optical shaping element 220 being less than 80mm, the focal length of the optical shaping element 220 being greater than or equal to 80mm can increase the spot diameter of the first beam g2 transmitted to the second nonlinear optical crystal 120, increase the contact area between the first beam g2 and the second nonlinear optical crystal 120, increase the conversion efficiency of the second nonlinear optical crystal 120, and reduce the energy of stray light output by the second nonlinear optical crystal 120.

[0088] For example, the focal length of the light shaping element 220 can be 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm or 200mm, etc.

[0089] In embodiments where the focal length of the light shaping element 220 is greater than or equal to 100mm, the conversion efficiency of the second nonlinear optical crystal 120 to the first beam g2 can be further increased, and the power of the second beam g3 output by the second nonlinear optical crystal 120 can be improved, thereby improving the energy of the beam output by the entire light source module 100.

[0090] In embodiments where the focal length of the light shaping element 220 is greater than or equal to 150mm, the spot diameter of the first beam g2 transmitted to the second nonlinear optical crystal 120 is larger, improving the conversion efficiency of the second nonlinear optical crystal 120. Simultaneously, it ensures that the edge rays of the first beam g2 are also transmitted to the second nonlinear optical crystal 120 and converted by it, thereby increasing the utilization rate of the first beam g2.

[0091] When the focal length of the optical shaping element 220 is greater than or equal to 80mm, the embodiments of this application do not limit the structure of the optical shaping element 220.

[0092] In some embodiments, the light shaping element 220 can be a focusing lens with a focal length greater than or equal to 80mm. This reduces the space occupied by the light shaping element 220, shortens the optical path length of the light source module 100, and reduces the size of the light source module 100.

[0093] In some embodiments, the light shaping element 220 can be a lens assembly including two, three, or four focusing lenses, and the overall focal length of the lens assembly is greater than or equal to 80mm. The light shaping element 220 includes multiple lenses, which can flexibly adjust the spot size and optimize conversion efficiency.

[0094] In some embodiments of this application, the spot diameter of the first beam g2 after being converged by the light shaping element 220 is greater than or equal to 30 μm (micrometers). Thus, the larger spot diameter of the first beam g2 transmitted to the second nonlinear optical crystal 120 is beneficial to improving the conversion efficiency of the second nonlinear optical crystal 120, thereby increasing the energy of the second beam g3 and improving the efficiency of the light source module 100.

[0095] For example, the spot diameter of the first beam g2 after being converged by the light shaping element 220 can be 30μm, 40μm, 50μm, 70μm, 80μm, 100μm, 130μm, 150μm, 180μm, 200μm or 245μm, etc.

[0096] In embodiments where the spot diameter of the first beam g2 after convergence by the light shaping element 220 is greater than or equal to 50 μm, the second nonlinear optical crystal 120 can make full use of the first beam g2 to generate more second beams g3, thereby improving the conversion efficiency of the second nonlinear optical crystal 120.

[0097] In embodiments where the spot diameter of the first beam g2 after convergence by the light shaping element 220 is greater than or equal to 150 μm, the edge rays in the first beam g2 can also be utilized by the second nonlinear optical crystal 120. Furthermore, the first beam g2 is more uniformly distributed in the second nonlinear optical crystal 120, which can further improve the conversion efficiency of the second nonlinear optical crystal 120 for the first beam g2 and increase the energy of the second beam g3.

[0098] As described above, the pulse width of the laser g1 output by the pulsed laser 210 is greater than 20 ps. After passing through the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120, the laser g1 can produce a second beam g3 with better spot quality and beam energy. By setting the aforementioned light shaping element 220 in the light source module 100, the spot quality and beam energy of the second beam g3 are both improved, and the conversion efficiency of the light source module 100 can also be improved.

[0099] In other embodiments of this application, the spot diameter of the first beam g2 transmitted to the light-receiving surface of the second nonlinear optical crystal 120 can be changed by other components. This ensures the spot diameter of the first beam g2 transmitted to the light-receiving surface of the second nonlinear optical crystal 120 is greater than or equal to 30 μm. In other words, the aforementioned light-shaping element can be omitted, and the spot diameter of the first beam g2 transmitted to the light-receiving surface of the second nonlinear optical crystal 120 can be changed by other components. For example, the spot diameter of the first beam g2 transmitted to the light-receiving surface of the second nonlinear optical crystal 120 can be adjusted by setting a pulsed laser 210 or by setting the distance between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120.

[0100] For example, the diameter of the light spot on the incident surface of the first beam g2 transmitted to the second nonlinear optical crystal 120 can be 30μm, 40μm, 50μm, 70μm, 80μm, 100μm, 130μm, 150μm, 180μm, 200μm or 245μm, etc.

[0101] In embodiments where the spot diameter of the first beam g2 transmitted to the incident surface of the second nonlinear optical crystal 120 is greater than or equal to 150 μm, the edge rays in the first beam g2 can also be utilized by the second nonlinear optical crystal 120. This can further improve the conversion efficiency of the second nonlinear optical crystal 120 for the first beam g2 and increase the energy of the second beam g3.

[0102] In some embodiments of this application, the light source module 100 may also include other optical elements for adjusting the optical path of the light source module 100.

[0103] Figure 3 This is a schematic diagram of another light source module 100 provided in an embodiment of this application. Figure 3 For the structure and performance of the medium-pulse laser 210, the first nonlinear optical crystal 110, and the second nonlinear optical crystal 120, please refer to the foregoing. Figure 2 The descriptions in the examples will not be repeated here.

[0104] Figure 3 In the light source module 100, a first polarizer 201 may be included. The first polarizer 201 is used to change the polarization direction of the laser g1, so that the polarization direction of the beam incident on the first polarizer 201 and the polarization direction of the beam emitted from the first polarizer 201 produce a specific deflection angle. The first polarizer 201 matches the optical axis of the laser g1 with that of the first nonlinear optical crystal 110.

[0105] For example, the light source module 100 may further include a first focusing lens 202 and a second focusing lens 203. The laser g1 passes through the first focusing lens 202 and the second focusing lens 203 in sequence and is then transmitted to the first nonlinear optical crystal 110. The first focusing lens 202 and the second focusing lens 203 focus the laser g1 in sequence to reduce the spot diameter of the laser g1 and increase the conversion efficiency of the first nonlinear optical crystal 110 for the laser g1.

[0106] This application embodiment does not limit the focal length of either the first focusing lens 202 or the second focusing lens 203. For example, the optical power of the first focusing lens 202 can be 100mm-200mm, such as 100mm, 120mm, 130mm, 150mm, 160mm, 180mm or 200mm.

[0107] For example, the optical power of the second focusing lens 203 can be 30mm-80mm, such as 30mm, 40mm, 50mm, 60mm, 70mm or 80mm.

[0108] The beam emitted from the first nonlinear optical crystal 110 includes a first beam g2, and may also include stray light and other beams. In some embodiments of this application, the light source module 100 may further include a first beam splitter 204, which is used to receive the beam emitted from the first nonlinear optical crystal 110 and split the beam into the first beam g2 and a first sub-beam ( Figure 3 (Not shown in the text). Among them, the wavelengths of the first beam g2 and the first sub-beam are different.

[0109] In some embodiments, a wavelength division multiplexer may also be referred to as a dichroic mirror.

[0110] Figure 3 In the example, the light source module 100 may also include a first reflector 205 and a second reflector 206. The first reflector 205 and the second reflector 206 are used to change the optical path of the light source module 100, so that the optical path of the light source module 100 is folded, thereby reducing the volume of the light source module 100.

[0111] The first beam g2 emitted from the first nonlinear optical crystal 110 passes through the first reflector 205 and the second reflector 206 in sequence, and the transmission path of the first beam g2 is changed twice. Figure 3 In the example, the transmission direction of the first beam g2 transmitted to the first reflector 205 is opposite to the transmission direction of the first beam g2 emitted from the second reflector 206.

[0112] It is understood that, in this embodiment of the application, the angle between the transmission direction of the first beam g2 before reaching the first reflector 205 and the transmission direction of the first beam g2 emitted from the second reflector 206 is not limited. It can be set according to the optical path requirements of the light source module 100. For example, the angle between the transmission direction of the first beam g2 before reaching the first reflector 205 and the transmission direction of the first beam g2 emitted from the second reflector 206 can be 60° (degrees) to 300°. For instance, this angle can be 60°, 80°, 100°, 120°, 150°, 180°, 200°, 220°, 240°, 270°, 280°, or 300°, etc.

[0113] In some embodiments of this application, the first reflector 205 is not necessary. Only one reflector may be provided in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120, for example, only the second reflector 206 may be provided. Alternatively, in some embodiments of this application, neither the first reflector 205 nor the second reflector 206 is necessary, and no reflector may be provided in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120.

[0114] In some embodiments of this application, three, four or more mirrors may be provided in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120.

[0115] Figure 3 In the light source module 100, a second polarizer 207 may be included, which is used to change the polarization direction of the first beam g2. The second polarizer 207 is located in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120. The second polarizer 207 is used to change the polarization direction of the first beam g2, so that the polarization direction of the beam incident on the second polarizer 207 and the polarization direction of the beam exiting the second polarizer 207 produce a specific deflection angle. The second polarizer 207 matches the optical axis of the first beam g2 with that of the second nonlinear optical crystal 120.

[0116] Figure 3 In the example, the second polarizer 207 is located in the optical path between the second reflector 206 and the second nonlinear optical crystal 120. In other words, the second nonlinear optical crystal 120 is used to receive the first beam g2 emitted from the second polarizer 207.

[0117] In some embodiments, the second polarizer 207 may be located in the optical path between the second reflector 206 and the first reflector 205. Alternatively, the second polarizer 207 may be located in the optical path between the first nonlinear optical crystal 110 and the first reflector 205.

[0118] Figure 3 In one embodiment, the light shaping element 220 is a focusing lens, located in the optical path between the second polarizer 207 and the second nonlinear optical crystal 120. In some embodiments of this application, the light shaping element 220 may be located in the optical path between the second reflecting mirror 206 and the first reflecting mirror 205. Alternatively, the light shaping element 220 may be located in the optical path between the first nonlinear optical crystal 110 and the first reflecting mirror 205. Alternatively, the light shaping element 220 may be located in the optical path between the second reflecting mirror 206 and the second polarizer 207. This application does not limit the scope of these embodiments.

[0119] In embodiments of this application, the light source module 100 may further include a second wavelength divider 214. The second wavelength divider 214 is used to receive the light beam emitted from the second nonlinear optical crystal 120 and divide the light beam into a second beam g3 and a second sub-beam. The second beam g3 and the second sub-beam have different wavelengths. Thus, the second wavelength divider 214 can narrow the wavelength band of the second beam g3.

[0120] In some embodiments of this application, the second wave splitter 214 is not necessary, and the light source module 100 may not be equipped with the second wave splitter 214.

[0121] Figure 3 The example shown has a high power for the second beam g3, which is greater than or equal to 10W.

[0122] The embodiments of this application are as follows: Figure 3 The parameters of each structure in the example are not limited. For example, the pulsed laser 210 is a Yb-doped fiber laser, and the pulse width of the laser g1 emitted by the Yb-doped fiber laser is 216 ps. The focal length of the first focusing mirror 202 is 150 mm, and the focal length of the second focusing mirror 203 is 50 mm. The first nonlinear optical crystal 110 is made of lithium triborate crystal and has a length of 10 cm. The reflection wavelength of the first reflecting mirror 205 is 532 nm. The reflection wavelength of the second reflecting mirror 206 is 532 nm. The focal length of the optical shaping element 220 is 100 mm. The second nonlinear optical crystal 120 is made of lithium triborate crystal and has a length of 30 cm. The M² factor of the second beam g3 emitted by the second nonlinear optical crystal 120 is less than 1.2.

[0123] In some embodiments of this application, the second beam g3 can be amplified before being output.

[0124] Figure 4 This is a schematic diagram of the structure of another light source module 100 provided in an embodiment of this application. Figure 4 and Figure 3 The differences include: the light source module 100 may also include: a third nonlinear optical crystal 130.

[0125] The third nonlinear optical crystal 130 is located in the optical path of the second beam g3. The third nonlinear optical crystal 130 is used to amplify the second beam g3 from the second nonlinear optical crystal 120 before outputting it.

[0126] The third nonlinear optical crystal 130 performs optical parametric amplification (OPA) on the second beam g3 before outputting it. The third nonlinear optical crystal 130 can further increase the energy of the second beam g3.

[0127] The material of the third nonlinear optical crystal 130 is described in the aforementioned description of the first nonlinear optical crystal 110, and will not be repeated here.

[0128] Figure 4 In the example, the light source module 100 may further include a third focusing mirror 208, which is located in the optical path between the second nonlinear optical crystal 120 and the third nonlinear optical crystal 130. The third focusing mirror 208 is used to converge the second beam g3 from the second nonlinear optical crystal 120 and transmit the converged second beam g3 to the third nonlinear optical crystal 130.

[0129] For example, the focal length of the third focusing lens 208 can be 30mm-100mm. For instance, the focal length of the third focusing lens 208 can be 30mm, 40mm, 50mm, 60mm, 80mm, 90mm, or 100mm. The third focusing lens 208 converges the second beam g3 to increase the conversion efficiency of the third nonlinear optical crystal 130.

[0130] Figure 4 In this light source module 100, a third polarizer 209 may also be included, which is located in the optical path between the third focusing lens 208 and the third nonlinear optical crystal 130. In other words, the third nonlinear optical crystal 130 is used to receive the second beam g3 emitted from the third polarizer 209.

[0131] The third polarizer 209 is used to change the polarization direction of the second beam g3. It causes a specific deflection angle between the polarization direction of the beam incident on the third polarizer 209 and the polarization direction of the beam exiting the third polarizer 209. The third polarizer 209 is used to change the polarization direction of the second beam g3 so that the second beam g3 matches the optical axis of the third nonlinear optical crystal 130.

[0132] It is understood that in some embodiments of this application, the third focusing lens 208 may be located in the optical path between the third polarizer 209 and the third nonlinear optical crystal 130, and this application does not limit this.

[0133] Figure 4 In the example, the second beam splitter 214 is located on the light-emitting side of the third nonlinear optical crystal 130. The second beam splitter 214 receives the light beam emitted from the third nonlinear optical crystal 130 and splits it into a second beam g3 and a second sub-beam. The second beam g3 and the second sub-beam have different wavelengths. Thus, the second beam splitter 214 can narrow the wavelength band of the second beam.

[0134] It is understood that in some embodiments, the second wave demultiplexer 214 may also be located in the optical path between the second nonlinear optical crystal 120 and the third nonlinear optical crystal 130. Alternatively, there may be two second wave demultiplexers 214, one located in the optical path between the second nonlinear optical crystal 120 and the third nonlinear optical crystal 130, and the other located on the light-emitting side of the third nonlinear optical crystal 130.

[0135] Figure 4 Examples and Figure 3 The differences in the examples also include: the light source module 100 does not include the second focusing lens 203.

[0136] Figure 4 In the example, the light shaping element 220 includes two focusing lenses, namely lens C1 and lens C2. The second beam g3 emitted from the first nonlinear optical crystal 110 is transmitted to the second nonlinear optical crystal 120 through lens C1 and lens C2 in sequence.

[0137] Figure 4 In the example, the second polarizer 207 is located in the optical path between the lens C1 and the first reflector 205.

[0138] As mentioned above Figure 3 The same applies to the examples. Figure 4 In the example, the arrangement order of the optical elements in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120 is not restricted.

[0139] The embodiments of this application are as follows: Figure 4 The parameters of each structure in the example are not limited. For example, the pulsed laser 210 is a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser. The focal length of the first focusing lens 202 is 400 mm. The first nonlinear optical crystal 110 is made of lithium triborate crystal and has a length of 120 μm. The focal length of lens C1 is 150 mm. The focal length of lens C2 is 75 mm. The second nonlinear optical crystal 120 is made of lithium triborate crystal. The third nonlinear optical crystal 130 is made of lithium triborate crystal.

[0140] In some embodiments of this application, the light source module 100 can amplify the second beam g3 multiple times.

[0141] Figure 5 This is a schematic diagram of the structure of another light source module 100 provided in an embodiment of this application. Figure 5 and Figure 4 The difference lies in the fact that the light source module 100 may also include a fourth nonlinear optical crystal 140. The fourth nonlinear optical crystal 140 is used to amplify the second beam g3 from the third nonlinear optical crystal 130 before outputting it.

[0142] The fourth nonlinear optical crystal 140 can further amplify the second beam g3, further increasing the power of the beam emitted from the light source module 100.

[0143] In some embodiments, the optical path between the third nonlinear optical crystal 130 and the fourth nonlinear optical crystal 140 may further include a focusing lens, which is used to converge the second beam g3 from the third nonlinear optical crystal 130, and the fourth nonlinear optical crystal 140 is used to receive the beam from the focusing lens. For example, the focal length of the focusing lens can be 50mm-100mm, such as 50mm, 60mm, 70mm, 80mm, 90mm or 100mm.

[0144] In some embodiments, the optical path between the third nonlinear optical crystal 130 and the fourth nonlinear optical crystal 140 may also include a reflector for changing the propagation direction of the light beam.

[0145] In some embodiments of this application, the light source module 100 may further include a fifth nonlinear optical crystal, a sixth nonlinear optical crystal, etc. The fifth and sixth nonlinear optical crystals are used for multi-stage amplification of the second beam g3.

[0146] In some embodiments of this application, the third nonlinear optical crystal 130 is not necessary. The second nonlinear optical crystal 120 can serve both the functions of optical parameter generation and optical parameter amplification. The following is in conjunction with... Figure 6 An example is provided.

[0147] Figure 6 This is a schematic diagram of another light source module 100 provided in an embodiment of this application. Figure 6 and Figure 3 The differences include: Figure 6 In the example, the light source module 100 may also include a reflective element 150. The reflective element 150 is used to reflect the second beam g3 from the second nonlinear optical crystal 120 back to the second nonlinear optical crystal 120. The second nonlinear optical crystal 120 is also used to amplify the second beam g3 from the reflective element 150 before outputting it.

[0148] In other words, the second beam g3 emitted from the second nonlinear optical crystal 120 is reflected by the reflecting element 150 and returns to the second nonlinear optical crystal 120, where it is amplified and output.

[0149] In this way, the second nonlinear optical crystal 120 can take into account both the generation and amplification of optical parameters, increase the power of the second beam g3 while saving the number of devices in the light source module 100, and also help to reduce the size of the light source module 100.

[0150] The present application does not limit the structure of the reflective element 150. For example, the reflective element 150 can be a mirror. Alternatively, the reflective element 150 can include a support and a reflective film, with the reflective film attached to the support.

[0151] Figure 6 In the example, the light source module 100 may further include a first isolator (ISO) 211, which is located in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120. The first isolator 211 is used to prevent reverse noise light from entering the first nonlinear optical crystal 110.

[0152] Figure 6 In the example, the light shaping element 220 includes two focusing lenses, namely lens C1 and lens C2. The second beam g3 emitted from the first nonlinear optical crystal 110 is transmitted to the second nonlinear optical crystal 120 through lens C1 and lens C2 in sequence.

[0153] Figure 6 In the example, the light source module 100 does not include Figure 3 The second reflecting mirror 206 is shown. It is understood that in some embodiments, Figure 6 The light source module 100 shown may not include the first reflector 205. Alternatively, in some embodiments, Figure 6 The light source module 100 shown may include a second reflector.

[0154] Figure 6 In the example, the light source module 100 may also include a third wave splitter 212, which is located in the optical path between the first nonlinear optical crystal 110 and the second nonlinear optical crystal 120.

[0155] The third beam splitter 212 projects the first beam g2 from the first nonlinear optical crystal 110 onto the second nonlinear optical crystal 120. The third beam splitter 212 also transmits the second beam g3 from the second nonlinear optical crystal 120. Thus, the optical path between the third beam splitter 212 and the second nonlinear optical crystal 120 becomes a shared optical path for both the first beam g2 and the second beam g3. This effectively saves space in the light source module 100.

[0156] In some embodiments of this application, the third beam splitter 212 is not necessary, and the transmission direction of the first beam g2 to the second nonlinear optical crystal 120 and the transmission direction of the second beam g3 after being amplified by the second nonlinear optical crystal 120 may be different.

[0157] The embodiments of this application are as follows: Figure 6The parameters of each structure in the example are not limited. For example, the pulsed laser 210 is a Yb:YAG laser. The focal length of the first focusing lens 202 is 150 mm, and the material of the second nonlinear optical crystal 120 includes lithium triborate crystal. The power of the second beam g3 output by the second nonlinear optical crystal 120 is 120 mW. The focal length of the second focusing lens 203 is 50 mm. The length of the first nonlinear optical crystal 110 is 50 μm.

[0158] In some embodiments of this application, the spectrum of the second beam g3 output by the light source module 100 can be further optimized using an injection seed component.

[0159] Figure 7 This is a schematic diagram of the structure of a light source module 100 including a seed injection component 160, provided for an embodiment of this application. Figure 7 In the example, the light source module 100 may also include a seed injection component 160.

[0160] Figure 7 In this configuration, the seed injection component 160 is used to output the third beam g4, and the second nonlinear optical crystal 120 is also used to receive the third beam g4 from the seed injection component 160. The wavelength band of the third beam g4 at least partially overlaps with the wavelength band of the second beam g3.

[0161] Thus, the seed injection component 160 can improve the conversion efficiency of the second nonlinear optical crystal 120. In addition, the third beam g4 output by the seed injection component 160 can narrow the band of the second beam g3, thereby narrowing the spectral width of the second beam g3.

[0162] Exemplarily, the seed injection component 160 includes a continuous-wave laser, and the third beam g4 output by the seed injection component 160 may also be referred to as the seed beam. The third beam g4 has a narrow bandwidth; in some embodiments, the bandwidth of the third beam g4 is less than or equal to 1 nm. In some embodiments, the bandwidth of the third beam g4 is less than or equal to 0.5 nm.

[0163] If the waveband of the third beam g4 and the waveband of the second beam g3 overlap at least partially, then both the third beam g4 and the second beam g3 are phase-matched with the second nonlinear optical crystal 120, causing the second nonlinear optical crystal 120 to output the second beam g3.

[0164] In other words, the second nonlinear optical crystal 120, which is phase-matched with the third beam g4, exerts an optical parametric amplification effect on the third beam g4. The second nonlinear optical crystal 120 exerts an optical parametric generation effect on the first beam g2. The third beam g4, which at least partially overlaps with the wavelength band of the second beam g3, narrows the spectral width of the beam output by the second nonlinear optical crystal 120, thereby improving the beam spot quality.

[0165] In some embodiments, the wavelength band of the third beam g4 overlaps with that of the second beam g3. For example, the center wavelength of the third beam g4 is equal to the center wavelength of the second beam g3. In some embodiments, the wavelength band of the third beam g4 overlaps with that of the second beam g3. In embodiments where the third beam g4 is a narrow-band light, the wavelength of the second beam g3 is equal to the wavelength of the third beam g4.

[0166] Figure 7 In the example, the light source module 100 may further include a second isolator 213 located in the optical path between the seed injection assembly 160 and the second nonlinear optical crystal 120. The second isolator 213 is used to prevent reverse noise light from entering the seed injection assembly 160.

[0167] Figure 7 In the example, the light source module 100 may further include a fourth focusing lens 217. The fourth focusing lens 217 receives the third beam g4 emitted from the seed injection assembly 160 and transmits the focused beam to the second nonlinear optical crystal 120. This can reduce the spot size of the third beam g4 transmitted to the second nonlinear optical crystal 120, improving the utilization rate of the third beam g4 by the second nonlinear optical crystal 120. This further improves the conversion efficiency of the second nonlinear optical crystal 120 for the first beam g2.

[0168] Figure 7 In the example, the light source module 100 may also include a third reflector 215 and a fourth wave splitter 216, both of which are located in the optical path between the seed injection assembly 160 and the second nonlinear optical crystal 120.

[0169] The third reflector 215 reflects the third beam g4 emitted from the seed injection assembly 160 to the fourth wave splitter 216. The fourth wave splitter 216 receives the first beam g2 from the first nonlinear optical crystal 110 and the third beam g4 from the third reflector 215, and projects the first beam g2 and the third beam g4 onto the second nonlinear optical crystal 120 through the first beam g2 and the reflected third beam g4. In this way, the first beam g2 and the third beam g4 can share the optical path between the fourth wave splitter 216 and the second nonlinear optical crystal 120, saving space in the light source module 100.

[0170] It is understood that in the embodiments of this application, the third reflector 215 and the fourth wave splitter 216 are not necessary, and the first beam g2 and the third beam g4 may not share the same optical path.

[0171] Figure 7 Zhongyu Figure 3For the same device as the example shown, please refer to the foregoing. Figure 3 The description in the text will not be repeated here.

[0172] In some embodiments, Figure 7 Examples can also be set Figure 4 The third nonlinear optical crystal 130 is shown. In some embodiments, Figure 7 Examples can also be set Figure 5 The third nonlinear optical crystal 130 and the fourth nonlinear optical crystal 140 are shown. In some embodiments, Figure 7 Examples can also be set Figure 6 The reflective element 150 shown.

[0173] In some embodiments of this application, the pulse width output by the pulsed laser 210 may be less than 20 ps.

[0174] Please return Figure 2 The light source module 100 includes a pulsed laser 210, a first nonlinear optical crystal 110, a second nonlinear optical crystal 120, and an optical shaping element 220. In some embodiments of this application, the pulse width output by the pulsed laser 210 may be less than 20 ps.

[0175] A pulsed laser 210 is used to output laser g1. The pulse width of laser g1 can be less than 20 ps or greater than or equal to 20 ps. A first nonlinear optical crystal 110 is used to receive the laser from the pulsed laser 210, perform frequency conversion, and output a first beam g2. An optical shaping element 220 is used to receive the first beam g2 from the first nonlinear optical crystal 110, converge the first beam g2, and output it. A second nonlinear optical crystal 120 is used to receive the first beam g2 from the optical shaping element 220 and output a second beam g3, wherein the center wavelength of the second beam g3 is greater than the center wavelength of the first beam g2.

[0176] The first nonlinear optical crystal 110 performs frequency conversion on the laser and outputs a first beam g2. The optical shaping element 220 converges the first beam g2, and the converged first beam g2 is then converted by the second nonlinear optical crystal 120 to form a second beam g3. In this optical path, the focal length of the optical shaping element 220 is greater than or equal to 80mm, and the spot size of the first beam g2 transmitted to the second nonlinear optical crystal 120 is relatively large. This allows the first beam g2 to enter the second nonlinear optical crystal 120 more uniformly and be fully converted, improving the conversion efficiency of the second nonlinear optical crystal 120 for the first beam g2, increasing the energy of the center wavelength of the second beam g3, and simultaneously improving the beam quality of the second beam g3.

[0177] For example, the focal length of the light shaping element 220 can be 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm or 200mm, etc.

[0178] In some embodiments, the spot diameter of the first beam g2 after being converged by the light shaping element 220 is greater than or equal to 30 μm (micrometers). Thus, the larger spot diameter of the first beam g2 transmitted to the second nonlinear optical crystal 120 is beneficial for improving the conversion efficiency of the second nonlinear optical crystal 120, thereby increasing the energy of the second beam g3. This improves the efficiency of the light source module 100.

[0179] For example, the spot diameter of the first beam g2 after being converged by the light shaping element 220 can be 30μm, 40μm, 50μm, 70μm, 80μm, 100μm, 130μm, 150μm, 180μm, 200μm or 245μm, etc.

[0180] Among them, the aforementioned Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The example shown also applies to examples of this pulsed laser 210 used for output pulse widths less than 20 ps.

[0181] In other words, in the embodiment where the light source module 100 includes the light shaping element 220, the pulse width of the laser g1 can be less than 20 ps, ​​or greater than or equal to 20 ps. The remaining structure in the light source module 100 can be the same as described above. Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The structures described are the same. They will not be repeated here.

[0182] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0183] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A light source module, characterized in that, The light source module includes: A pulsed laser, wherein the pulsed laser is used to output laser light with a pulse width greater than or equal to 20 ps; A first nonlinear optical crystal, the first nonlinear optical crystal being used to receive laser light from the pulsed laser, perform frequency conversion, and output a first beam; and A second nonlinear optical crystal is used to receive the first beam from the first nonlinear optical crystal and output a second beam, wherein the center wavelength of the second beam is greater than the center wavelength of the first beam.

2. The light source module according to claim 1, characterized in that, The pulsed laser is used to output a laser pulse width greater than or equal to 50 ps.

3. The light source module according to claim 1 or 2, characterized in that, The light source module further includes: a light shaping element; the focal length of the light shaping element is greater than or equal to 80mm; The second nonlinear optical crystal, used to receive the first beam from the first nonlinear optical crystal and output a second beam, includes: The light shaping element is used to receive the first beam from the first nonlinear optical crystal, converge the first beam, and output it; the second nonlinear optical crystal is used to receive the first beam from the light shaping element and output the second beam.

4. The light source module according to claim 3, characterized in that, The diameter of the first beam spot after being converged by the light shaping element is greater than or equal to 30 μm.

5. The light source module according to claim 1 or 2, characterized in that, The diameter of the light spot transmitted from the first beam to the incident surface of the second nonlinear optical crystal is greater than or equal to 30 μm.

6. The light source module according to any one of claims 1-5, characterized in that, The light source module further includes a third nonlinear optical crystal, which is used to amplify the second beam from the second nonlinear optical crystal before outputting it.

7. The light source module according to claim 6, characterized in that, The light source module further includes a fourth nonlinear optical crystal, which is used to amplify the second beam from the third nonlinear optical crystal before outputting it.

8. The light source module according to any one of claims 1-7, characterized in that, The light source module further includes a seed injection component for outputting a third beam, and the second nonlinear optical crystal is also used to receive the third beam from the seed injection component; the wavelength of the third beam and the wavelength of the second beam at least partially overlap.

9. The light source module according to any one of claims 1-8, characterized in that, The light source module further includes a reflective element, which is used to reflect the second beam from the second nonlinear optical crystal back to the second nonlinear optical crystal; The second nonlinear optical crystal is also used to amplify the second beam from the reflective element before outputting it.

10. The light source module according to any one of claims 1-9, characterized in that, The pulsed laser includes: Any one of the following: Yb-doped fiber laser, Er-doped fiber laser, Nd-doped fiber laser, Tm-doped fiber laser, Yb:YAG solid-state laser, Nd:YAG solid-state laser, Nd:YVO4 solid-state laser, or Ti:Sapphire laser.

11. The light source module according to any one of claims 1-10, characterized in that, The first nonlinear optical crystal is a frequency doubling crystal.

12. A light source module, characterized in that, The light source module includes: A pulsed laser, wherein the pulsed laser is used to output laser light; A first nonlinear optical crystal is used to receive laser light from the pulsed laser, perform frequency conversion, and output a first beam. An optical shaping element, wherein the optical shaping element is used to receive the first beam of light from the first nonlinear optical crystal, converge the first beam of light, and output it; the focal length of the optical shaping element is greater than or equal to 80 mm; and A second nonlinear optical crystal is used to receive the first beam from the light shaping element and output a second beam, wherein the center wavelength of the second beam is greater than the center wavelength of the first beam.

13. The light source module according to claim 12, characterized in that, The diameter of the first beam focused by the light shaping element is greater than or equal to 30 μm.

14. A laser processing device, characterized in that, The laser processing equipment includes: a lens assembly and a light source module as described in any one of claims 1-13, wherein the lens assembly receives the second beam from the light source module.

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