Stimulated Raman scattering beam splitting system
By utilizing a stimulated Raman scattering beam splitting system, and employing multiple refractions, reflections, and diffraction by a beam splitting grating, the problem of separating lasers with similar wavelengths was solved. This enabled effective beam splitting of 563nm and 599nm wavelength lasers, improving the beam splitting effect and damage resistance.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- 段传恺
- Filing Date
- 2025-06-30
- Publication Date
- 2026-04-28
AI Technical Summary
In the existing technology, 532nm, 563nm and 599nm wavelength lasers generated by laser pumping with a wavelength of 532nm cannot be directly split by a beam splitter, especially the 563nm and 599nm wavelength lasers are difficult to separate.
A stimulated Raman scattering beam splitting system is adopted, including a first convex lens, a first beam splitting grating, a pinhole aperture, a second convex lens, a first beam splitting prism, a second beam splitting prism, a second beam splitting grating, and a light shield. Wavelength separation is achieved through multiple refractions and reflections of the beam and diffraction by the beam splitting grating.
It effectively solves the problem of beam splitting lasers with similar wavelengths, realizes beam splitting of 563nm and 599nm wavelength lasers at close range, and improves the damage resistance. The split laser can be further applied.
Smart Images
Figure CN224176822U_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of optical technology, and in particular to a stimulated Raman scattering beam splitting system. Background Technology
[0002] Laser pumping that generates 532 nm laser light will also generate laser light with wavelengths of 504 nm, 563 nm, and 599 nm. Since the wavelengths of 563 nm and 599 nm laser light are similar to those of 532 nm laser light, they cannot be directly split by a beam splitter grating. Therefore, a beam splitting system is urgently needed to solve this problem. Utility Model Content
[0003] This disclosure provides a stimulated Raman scattering spectrometer to at least solve the above-mentioned technical problems existing in the prior art.
[0004] The first aspect of this disclosure provides a stimulated Raman scattering beam splitting system, comprising: a first convex lens 3, a first beam splitting grating 4, a pinhole aperture 5, a second convex lens 6, a first beam splitting prism 7, a second beam splitting prism 8, a second beam splitting grating 9, and a light shield 10.
[0005] The first beam is incident on the first convex lens 3, and after being focused, it exits from the first convex lens 3 and is incident on the first beam splitter grating 4; the first beam includes at least two wavelengths of laser light;
[0006] After the first beam exits from the first beam splitter 4, it is incident on the pinhole aperture 5;
[0007] After the first beam exits from the aperture stop 5, it enters the second convex lens 6, and after being focused by the second convex lens 6, it enters the first beam splitter 7 and the second beam splitter 8 to obtain the second beam.
[0008] After the second beam is incident on the second beam splitter 9 for beam splitting, it is incident on the light shield 10.
[0009] In the above scheme, the system also includes a pump light source 1 and a barium nitrate crystal 2;
[0010] The pump light source 1 is used to generate a laser beam including at least two wavelengths;
[0011] The light beam is emitted from the pump light source 1 and then emitted through the barium nitrate crystal 2 to obtain a first light beam; the first light beam is collimated light.
[0012] In the above scheme, the distance between the pinhole aperture 5 and the first convex lens 3 is the same as the distance between the pinhole aperture 5 and the second convex lens 6.
[0013] In the above scheme, the distance between the first convex lens 3 and the second convex lens 6 is twice the focal length of the first convex lens 3 or the second convex lens 6, so that the first beam, after passing through the first convex lens 3, the first beam splitter grating 4 and the second convex lens 6, is incident parallel to the first beam splitter prism 7.
[0014] In the above scheme, the first beam is incident on the first beam splitter 7, and after refraction, the third beam is emitted from the first beam splitter 7; the angle between the first beam and the third beam is the minimum deflection angle of the first beam splitter 7.
[0015] The third beam is incident on the second beam splitter 8, and after refraction, the second beam is emitted from the second beam splitter 8; the angle between the third beam and the second beam is the minimum deflection angle of the second beam splitter 8.
[0016] In the above scheme, the first surface of the first beam splitter 7 and the first surface of the second beam splitter 8 are blackened.
[0017] The first surface of the first beam splitter 7 is an end surface other than the first beam incident surface and the third beam exit surface; the first surface of the second beam splitter 8 is an end surface other than the third beam incident surface and the second beam exit surface.
[0018] In the above scheme, the focal length of the first convex lens 3 and the second convex lens 6 is 15 cm, and the light transmission diameter is 32 mm.
[0019] In the above scheme, the first beam splitter grating 4 has a line density of 300 lines per millimeter and a grating constant of 3.33 × 10⁻⁶. -6 rice;
[0020] The second beam splitter grating 9 has a line density of 100 lines per millimeter and a grating constant of 10. -5 rice.
[0021] In the above scheme, both the first beam splitter 7 and the second beam splitter 8 are quartz beam splitters with a 60° angle, a side length of 67 mm, and a thickness of 50 mm.
[0022] In the above scheme, the aperture of the pinhole aperture 5 is 2 mm;
[0023] The light-shielding plate 10 is a light-shielding plate with light-transmitting holes.
[0024] The stimulated Raman scattering beam splitting system disclosed herein comprises a first convex lens 3, a first beam splitting grating 4, a pinhole aperture 5, a second convex lens 6, a first beam splitting prism 7, a second beam splitting prism 8, a second beam splitting grating 9, and a light-shielding plate 10. A first beam is incident on the first convex lens 3, focused, and exits from the first convex lens 3, then incident on the first beam splitting grating 4. The first beam includes at least two wavelengths of laser light. After exiting the first beam splitting grating 4, the first beam is incident on the pinhole aperture 5. After exiting the pinhole aperture 5, the first beam is incident on the second convex lens 6, focused, and then incident on the first beam splitting prism 7 and the second beam splitting prism 8 to obtain a second beam. The second beam is incident on the second beam splitting grating 9 for beam splitting, and then incident on the light-shielding plate 10. The light-shielding plate 10 displays light spots corresponding to at least two wavelengths of light. Thus, the system composed of a double grating and a double prism can achieve beam splitting of stimulated Raman scattering light.
[0025] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description
[0026] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which:
[0027] In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.
[0028] Figure 1 The spectral detection results of stimulated Raman scattering light generated by laser pumping are shown;
[0029] Figure 2 A photograph of the stimulated Raman scattering spectrometer provided in the embodiments of this disclosure is shown.
[0030] Figure 3 A schematic diagram of a first alternative structure of the stimulated Raman scattering beam splitting system provided in this disclosure embodiment is shown;
[0031] Figure 4 A schematic diagram of a second alternative structure of the stimulated Raman scattering beam splitting system provided in this embodiment of the present disclosure is shown;
[0032] Figure 5 A schematic diagram of a third alternative structure of the stimulated Raman scattering beam splitting system provided in this disclosure embodiment is shown;
[0033] Figure 6The diagram shows the spectral dispersion effect obtained by the stimulated Raman scattering spectral dispersion system provided in the embodiments of this disclosure;
[0034] Figure 7 The actual software screenshot of the light spot spectrum with a center wavelength of 563.71 nm is shown;
[0035] Figure 8 The diagram shows the waveforms of the stimulated Raman scattering beams at each stage obtained using the stimulated Raman scattering beam splitting system provided in the embodiments of this disclosure.
[0036] The labels in the diagram are as follows: 1-Pump light source, 2-Barium nitrate crystal, 3-First convex lens, 4-First beam splitter grating, 5-Pinhole aperture, 6-Second convex lens, 7-First beam splitter prism, 8-Second beam splitter prism, 9-Second beam splitter grating, 10-Light shield. Detailed Implementation
[0037] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.
[0038] Figure 1 The spectral results of stimulated Raman scattering generated by laser pumping are shown.
[0039] like Figure 1 As shown, the 532nm wavelength laser beam generated by laser pumping includes 504nm, 532nm, 563nm and 599nm wavelength lasers. Since the wavelengths of 532nm, 563nm and 599nm wavelength lasers are very close (or the wavelength difference is less than a certain value), it is difficult to separate them directly using a beam splitter.
[0040] The diffraction angles of lasers of different wavelengths can be calculated using the grating equation:
[0041] dsinθ=mλ
[0042] Where d is the grating constant, θ is the diffraction angle, m is the order, and λ is the wavelength.
[0043] If the scale density of the beam splitter grating is N = 600 l / mm, the wavelength is λ = 563 nm, and the order is m = 1, then:
[0044]
[0045] Furthermore, arcsinθ = 19.70°.
[0046] Similarly, if the scale density of the beam splitter grating is N = 600 l / mm and the wavelength is λ = 599 nm, then sinθ = 0.3586826347 and arcsinθ = 21.02°. If the scale density of the beam splitter grating is N = 600 l / mm and the wavelength is λ = 532 nm, and the order is m = 0, then sinθ = 0 and arcsinθ = 0.
[0047] That is, the Raman output lasers with wavelengths of 563nm and 599nm have a diffraction angle difference of 1.3°. Considering that the longer the transmission distance, the larger the light spot, and the laser spot will become fainter if the distance is too far, it is difficult to separate the Raman output lasers with wavelengths of 563nm and 599nm using a beam splitter alone.
[0048] Based on this, the present disclosure provides a stimulated Raman scattering beam splitting system that can effectively solve the problems of not being able to split high peak power lasers and the poor damage resistance caused by using only a beam splitting grating. This system can perform beam splitting at close range, and the split laser can be reused.
[0049] Figure 2 A photograph of a physical image of the stimulated Raman scattering spectrometer provided in an embodiment of this disclosure is shown.
[0050] Figure 3 A schematic diagram of a first alternative structure of the stimulated Raman scattering spectrometer provided in this disclosure is shown.
[0051] like Figure 3 As shown, the stimulated Raman scattering beam splitting system includes a first convex lens 3, a first beam splitting grating 4, a pinhole aperture 5, a second convex lens 6, a first beam splitting prism 7, a second beam splitting prism 8, a second beam splitting grating 9, and a light shield 10.
[0052] The first convex lens 3, the first beam splitter 4, the pinhole aperture 5, and the second convex lens 6 are arranged sequentially on the same horizontal plane; the second beam splitter 9 and the light-shielding plate 10 are arranged sequentially on the same vertical plane.
[0053] On the horizontal plane, the order of the first convex lens 3, the first beam splitter 4, the pinhole aperture 5, and the second convex lens 6 from left to right or from right to left is the same; on the vertical plane, the order from top to bottom is the second beam splitter 9 and the light shield 10.
[0054] In some embodiments, a first light beam emitted from a pump light source is incident on a first convex lens 3, focused, and exits from the first convex lens 3, then incident on a first beam splitter grating 4; the first light beam includes at least two wavelengths of laser light, namely at least 532nm wavelength laser light, 563nm wavelength laser light, and 599nm wavelength laser light.
[0055] After exiting the first beam splitter 4, the first beam is incident on the pinhole stop 5. The pinhole stop 5 is placed at the focal point of the first convex lens 3, and also at the focal point of the second convex lens 6. That is, the pinhole stop is positioned between the first convex lens 3 and the second convex lens 6, and the distance between the pinhole stop and the first convex lens 3 and the second convex lens 6 is the focal length of either the first convex lens 3 or the second convex lens 6. Furthermore, the distance between the first convex lens 3 and the second convex lens 6 is twice the focal length of either the first convex lens 3 or the second convex lens 6. In this way, it can play a mode-limiting role, selecting the strongest diffraction order of the beam splitter grating and removing other stray light.
[0056] After the first beam exits from the aperture stop 5, it enters the second convex lens 6, and after being focused by the second convex lens 6, it enters the first beam splitter 7 and the second beam splitter 8 to obtain the second beam.
[0057] In specific implementation, such as Figure 3 As shown, the first beam enters from the B2 surface (incident surface) of the first beam splitter 7 and exits from the B3 surface (exit surface) of the first beam splitter 7. The B1 surface (first surface) of the first beam splitter 7 is blackened to overcome stray light.
[0058] The beam emitted from the first beam splitter 7 enters through the B5 surface (incident surface) of the second beam splitter 8 and exits through the B6 surface (exit surface) of the second beam splitter 8. The B4 surface (first surface) of the second beam splitter 8 is blackened to overcome stray light.
[0059] After the second beam is incident on the second beam splitter 9 for beam splitting, it is incident on the light shield 10; the light shield 10 displays light spots corresponding to at least two wavelength beams.
[0060] Figure 4 A schematic diagram of a second alternative structure of the stimulated Raman scattering spectrometer provided in this embodiment is shown.
[0061] In some embodiments, such as Figure 4 As shown, the stimulated Raman scattering beam splitting system includes a pump light source (1), a barium nitrate crystal (2), a first convex lens (3), a first beam splitting grating (4), a pinhole aperture (5), a second convex lens (6), a first beam splitting prism (7), a second beam splitting prism (8), a second beam splitting grating (9), and a light shield (10).
[0062] In this configuration, the pump light source (1), barium nitrate crystal (2), first convex lens (3), first beam splitter (4), pinhole aperture (5), and second convex lens (6) are on the same horizontal plane; the second beam splitter (9) and light-shielding plate (10) are on the same vertical plane. Optionally, the centers or focal points of the pump light source (1), barium nitrate crystal (2), first convex lens (3), first beam splitter (4), pinhole aperture (5), and second convex lens (6) are on the same horizontal plane.
[0063] In some embodiments, the pump light source (1) is used to generate a beam of laser light including at least two wavelengths; specifically, the pump light source (1) can be used to generate a laser light including a wavelength of 532nm, including other wavelength lasers, the other wavelength lasers including at least one of 504nm laser, 563nm laser and 599nm laser.
[0064] In some embodiments, the light beam exits from the pump light source (1) and then exits through the barium nitrate (Ba(NO3)2) crystal (2) to obtain a first light beam; the first light beam is collimated light.
[0065] Specifically, the diameter of the stimulated scattering light plate of barium nitrate crystal 2 is 0.7 mm and the divergence angle is less than 2 mrad. Therefore, the stimulated scattering light (first beam) emitted from the outlet end face of barium nitrate crystal 2 is collimated light.
[0066] After exiting from the barium nitrate crystal 2, the first beam is incident on the first convex lens 3 and focused by the first convex lens 3; after being focused, it exits from the first convex lens 3 and is incident on the first beam splitter grating 4; the first beam includes laser light of at least two wavelengths;
[0067] After the first beam exits from the first beam splitter 4, it is incident on the pinhole aperture 5;
[0068] After exiting the aperture stop 5, the first beam enters the second convex lens 6, is focused by the second convex lens 6, and then enters the first beam splitter 7. After being focused by the second convex lens 6, the first beam exits the second convex lens 6 in the form of parallel light and enters the first beam splitter 7.
[0069] Thus, the structure of the biconvex lens can effectively compress the divergence angle of the first beam, making the first beam as parallel as possible and completely incident on the first beam splitter 7.
[0070] In some embodiments, the first beam is incident on the first beam splitter 7, and after refraction, a third beam exits from the first beam splitter 7; the angle between the first beam and the third beam is the minimum deflection angle of the first beam splitter 7; the third beam is incident on the second beam splitter 8, and after refraction, a second beam exits from the second beam splitter 8; the angle between the third beam and the second beam is the minimum deflection angle of the second beam splitter 8. That is, both the first beam splitter 7 and the second beam splitter 8 are set in the optical path with minimum deflection angles to achieve optimal spectral dispersion; and setting two beam splitters can maximize the dispersion of green wavelengths with similar wavelengths, making the spectral dispersion result more obvious.
[0071] In some embodiments, the first surface B1 of the first beam splitter 7 and the first surface B4 of the second beam splitter 8 are blackened; the first surface of the first beam splitter 7 is an end surface other than the first beam incident surface and the third beam exit surface; the first surface of the second beam splitter 8 is an end surface other than the third beam incident surface and the second beam exit surface.
[0072] In some embodiments, the second beam is incident on the second beam splitter grating 9 for beam splitting, and then incident on the light shield 10; the light shield 10 displays light spots corresponding to at least two wavelength beams.
[0073] Figure 5 A schematic diagram of a third alternative structure of the stimulated Raman scattering spectrometer provided in this disclosure is shown.
[0074] like Figure 5 As shown, pump source 1 is a 532nm wavelength laser pump source; the first convex lens 3 and the second convex lens 6 are both convex lenses with a focal length of 15cm and a light-transmitting diameter of 32mm; the first beam splitter grating 4 has a scribe line density of 300l / mm and a grating constant of 3.33×10⁻⁶. -6 m; the second beam splitter grating 9 has a line density of 100 l / mm and a grating constant of 10. -5 m. Both the first beam splitter grating 4 and the second beam splitter grating 9 are transmission beam splitters.
[0075] Both the first beam splitter 7 and the second beam splitter 8 are quartz beam splitters with a 60° angle, a side length of 67 mm, and a thickness of 50 mm. B1 and B4 are both blackened.
[0076] The aperture of the pinhole aperture 5 is 2mm; the light shield 10 is a perforated light shield.
[0077] In some embodiments, Figure 5The stimulated Raman scattering beam splitting system shown includes a 532nm wavelength laser beam emitted from a pump source (1) and first acting on a Ba(NO3)2 crystal. The stimulated scattered light (i.e., the first beam) passing through the Ba(NO3)2 crystal has a spot diameter of approximately 0.7mm and a divergence angle of less than 2mrad. Therefore, the first beam exiting from the exit end face of the Ba(NO3)2 crystal is collimated light. Figure 5 The illustrated beam diagram represents the first beam filling the first convex lens 3. The first beam is first focused by the first convex lens 3, and the distance from the exit facet of the Ba(NO3)2 crystal to the center of the first convex lens 3 is 10 mm. The distance between the center of the first convex lens 3 and the first beam splitter 4 is 60 mm. The pinhole stop 5 is placed at the focal point of the first convex lens 3, at a distance of 150 mm from the first convex lens 3; the distance between the pinhole stop 5 and the second convex lens 6 is also 150 mm. The pinhole stop 5 is used for mode limiting in the optical path, with the purpose of selecting the strongest diffraction order of the first beam splitter 4 and removing other stray light. The distance between the first convex lens 3 and the second convex lens 6 is twice the focal length of the first convex lens 3 (i.e., 300 mm), which is used to focus, initially split, and filter the first beam, and then convert it back into parallel light before entering the prism. This double convex lens structure can effectively compress the divergence angle of the stimulated scattering light, converting it into parallel light as much as possible, and allowing it to completely enter the first beam splitter prism 7. Both the first beam splitter 7 and the second beam splitter 8 are positioned at their minimum deviation angles. The combination of the first beam splitter 7 and the second beam splitter 8 is also intended to maximize the dispersion of green light with similar wavelengths. Finally, a second beam splitter grating 9 with a 100 l / mm diameter is placed 120 mm from the light exit point of the second beam splitter 8. The second beam passing through the first beam splitter 7 and the second beam splitter 8 interferes with the second beam splitter grating 9 to obtain diffracted light, allowing for the measurement of the highest order of diffraction.
[0078] Thus, the stimulated Raman scattering beam splitting system provided in this embodiment can be regarded as a cavity-less Raman laser that has been pumped once, and the output is stimulated Raman scattering laser with multiple wavelengths such as 563nm and 599nm.
[0079] Figure 6 A diagram showing the spectral dispersion effect obtained by the stimulated Raman scattering spectral dispersion system provided in the embodiments of this disclosure is shown. Figure 7 The image shows a screenshot of the actual light spot spectrum with a center wavelength of 563.71 nm.
[0080] Figure 8 The diagram shows the waveforms of the stimulated Raman scattering beams at each stage obtained using the stimulated Raman scattering beam splitting system provided in the embodiments of this disclosure.
[0081] The stimulated Raman scattering beam splitting system provided in this embodiment utilizes a combination structure of "double grating + double prism," resulting in good beam splitting performance and the ability to split relatively high-power stimulated Raman scattered light. A light-shielding plate 10 is placed at a distance of 2200 mm from the second beam splitting grating 9, and an image acquisition device can be used to capture the effect image after beam splitting.
[0082] In some embodiments, the stimulated scattered light of each order exits at a certain exit angle and is distributed in concentric rings. The highest intensity of the Stokes light of each order is located at the center of the rings and they are superimposed. After passing through the stimulated Raman scattering spectrometer, the three wavelengths of light obtained are all the same size. This is because during the spectrometer's process, the stimulated Raman scattered light of each order suffers significant loss, so the surrounding rings are consumed. Only the stronger beam at the center of the ring is observed after the spectrometer passes through. Similarly, due to the spectrometer's loss, the higher-order Stokes light cannot be observed as a spot, leaving only three spots. The spectra of the three spots are then measured. A light-shielding plate 10 with a light-passing aperture is used to select and allow only one wavelength of laser light to pass through. After focusing by a lens, the energy of the stimulated Raman scattered light is adjusted by a light intensity modulation system composed of two polarizers. The light is then attenuated by a frosted glass plate before entering the spectrometer for spectral analysis. Finally, the light is... Figure 6 In the light spot diagram shown, each light spot corresponds to a single wavelength. The measured center wavelengths from right to left are 532.41nm, 563.67nm, and 599.71nm, which correspond to the pump light, the positive first-order Stokes light, and the positive second-order Stokes light, respectively.
[0083] use Figure 5 The device 11 (including an oscilloscope, a pulse photodetector, and a diffuse reflection screen) measures the pulse width of the three light spots generated after beam splitting: the pump light spot, the positive first-order Stokes light spot, and the positive second-order Stokes light spot. A light-shielding plate 10 with a light-passing aperture is used to select the light spots, allowing the light spots corresponding to each wavelength of laser light to pass through the measurement area, be reflected by the diffuse reflection screen, and then have their waveforms acquired and measured using a pulse photodetector. The oscilloscope model is TekTDS2022C. The pulse width waveforms of the pump light, positive first-order Stokes light, and positive second-order Stokes light after beam splitting are measured at a laser power supply operating voltage of 560V, pump energy of 107.94mJ, and pump pulse width of 12.36ns, as shown below. Figure 8As shown, the Stokes pulse widths of each order were significantly compressed and narrowed compared to the pump pulse width. Furthermore, the pump beam and the first-order Stokes beam exhibited peak bifurcation after splitting, while the peak of the second-order Stokes beam remained intact. The pump beam pulse width after splitting was 12.93 ns, essentially the same as before splitting, while the pulse widths of the first-order and second-order Stokes beams were 7.68 ns and 3.68 ns, respectively. Changing the pump beam output energy did not prevent the peak bifurcation phenomenon from recurring.
[0084] It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this application can be achieved, and this is not limited herein.
[0085] Furthermore, the terms "first" and "second" 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.
[0086] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.
Claims
1. A stimulated Raman scattering spectroscopic system, characterized in that, The system includes: a first convex lens (3), a first beam splitter (4), a pinhole aperture (5), a second convex lens (6), a first beam splitter (7), a second beam splitter (8), a second beam splitter (9), and a light shield (10); The first beam is incident on the first convex lens (3), and after being focused, it exits from the first convex lens (3) and is incident on the first beam splitter (4); the first beam includes at least two wavelengths of laser light; After the first beam exits from the first beam splitter (4), it enters the pinhole aperture (5); After the first beam exits from the aperture stop (5), it enters the second convex lens (6), and after being focused by the second convex lens (6), it enters the first beam splitter (7) and the second beam splitter (8) to obtain the second beam. After the second beam is incident on the second beam splitter (9) for beam splitting, it is incident on the light shield (10).
2. The system according to claim 1, characterized in that, The system also includes a pump light source (1) and a barium nitrate crystal (2); The pump light source (1) is used to generate a beam of laser light including at least two wavelengths; The light beam is emitted from the pump light source (1) and then emitted through the barium nitrate crystal (2) to obtain a first light beam; the first light beam is collimated light.
3. The system according to claim 1, characterized in that, The distance between the pinhole aperture (5) and the first convex lens (3) is the same as the distance between the pinhole aperture (5) and the second convex lens (6).
4. The system according to claim 1, characterized in that, The distance between the first convex lens (3) and the second convex lens (6) is twice the focal length of the first convex lens (3) or the second convex lens (6), so that the first beam passes through the first convex lens (3), the first beam splitter (4) and the second convex lens (6) and is incident parallel to the first beam splitter (7).
5. The system according to claim 1, characterized in that, The first beam is incident on the first beam splitter (7), and after refraction, the third beam is emitted from the first beam splitter (7); the angle between the first beam and the third beam is the minimum deflection angle of the first beam splitter (7); The third beam is incident on the second beam splitter (8), and after refraction, the second beam is emitted from the second beam splitter (8); the angle between the third beam and the second beam is the minimum deflection angle of the second beam splitter (8).
6. The system according to claim 1, characterized in that, The first surface of the first beam splitter (7) and the first surface of the second beam splitter (8) are coated with black. The first surface of the first beam splitter (7) is an end surface other than the first beam incident surface and the third beam exit surface; the first surface of the second beam splitter (8) is an end surface other than the third beam incident surface and the second beam exit surface.
7. The system according to claim 1, characterized in that, The focal length of the first convex lens (3) and the second convex lens (6) is 15 cm, and the light transmission diameter is 32 mm.
8. The system according to claim 1, characterized in that, The first beam splitter grating (4) has a line density of 300 lines per millimeter and a grating constant of 3.33 × 10⁻⁶. -6 rice; The second beam splitter grating (9) has a line density of 100 lines per millimeter and a grating constant of 10. -5 rice.
9. The system according to claim 1, characterized in that, Both the first beam splitter (7) and the second beam splitter (8) are quartz beam splitters with a 60° angle, a side length of 67 mm, and a thickness of 50 mm.
10. The system according to claim 1, characterized in that, The aperture of the pinhole aperture (5) is 2 mm; The light-shielding plate (10) is a light-shielding plate with light-transmitting holes.