A high-speed collision flash spectral detection system based on image intensifier

Abstract

This invention discloses an ultra-high-speed collisional flash spectral detection system based on an image intensifier, which addresses the technical problems of existing detection systems, such as severe sagittal astigmatism and poor spot convergence, caused by cumbersome assembly processes and poor measurement stability. The detection system includes a slit, a first folded-axis mirror, a curved prism, a second folded-axis mirror, a correction mirror group, and a planar grating arranged sequentially along the optical path, as well as an image intensifier. The correction mirror group is an optical multiplexing lens group, including a first positive lens, a first negative lens, and a second positive lens arranged sequentially. The first positive lens, the first negative lens, and the second positive lens form a collimating lens group along the incident light path and an imaging lens group along the reflected light path. The overall system structure is relatively compact. By combining the correction mirror group with the curved prism, the system's sagittal astigmatism is significantly reduced, and the spot convergence is enhanced.

Description

Technical Field

[0001] This invention relates to a spectral detection system, and more particularly to an ultra-high-speed collisional flash spectral detection system based on an image intensifier. Background Technology

[0002] High-resolution spectrometers are used to detect the spectral information of high-speed collisions. Since the spectral information of flash collisions is concentrated in the ultraviolet and visible light regions, their imaging principle is generally based on the Czerny-Turner structure and the M-Turner structure according to existing optical models.

[0003] The above two types of detection systems are currently widely used. Their structure is generally composed of off-axis mirrors and planar gratings. However, due to the complicated assembly process and poor measurement stability, the detection systems are prone to severe sagittal astigmatism and poor convergence of diffuse spots. Summary of the Invention

[0004] The purpose of this invention is to provide an ultra-high-speed collisional flash spectral detection system based on an image intensifier, which solves the technical problems of existing detection systems, such as severe sagittal astigmatism and poor convergence of diffuse spots, due to the cumbersome assembly process and poor measurement stability.

[0005] To achieve the above objectives, the technical solution of the present invention is as follows:

[0006] A high-speed collisional flash spectral detection system based on an image intensifier is characterized by:

[0007] It includes a slit, a first folding mirror, a curved prism, a second folding mirror, a correction mirror group, and a planar grating arranged sequentially along the optical path, as well as an image intensifier;

[0008] The slit is used to limit the incident light energy and spectral sampling interval. After passing through the slit, the incident light is reflected by the first folding mirror to the curved prism, and then transmitted through the curved prism to the second folding mirror. The curved prism is a plano-convex off-axis positive lens, with its planar side close to the curved prism and its convex side close to the second folding mirror.

[0009] Both the first and second folding mirrors are plane mirrors, wherein the plane of the first folding mirror forms a 45° angle with the optical axis of the incident light, and the plane of the second folding mirror is parallel to the plane of the first folding mirror.

[0010] The correction lens group is an optical multiplexing lens group, which is located on the reflected light path of the second folding mirror; the correction lens group includes a first positive lens, a first negative lens and a second positive lens arranged in sequence; the first positive lens, the first negative lens and the second positive lens form a collimating lens group along the incident light path and an imaging lens group along the reflected light path.

[0011] The planar grating is located on the side of the transmission path of the collimating lens group closer to the second positive lens, and is used to disperse the light beam passing through the collimating lens group; the dispersed light signal is transmitted through the imaging lens group, reflected by the second folding mirror, and converged by the curved prism before entering the image intensifier.

[0012] The image intensifier is located on the side of the curved prism near the first folded-axis mirror, and is used to amplify the converging light signal, thereby enhancing the detection sensitivity of the system.

[0013] Furthermore, it also includes a compensation lens group, which is a second negative lens located between the curved prism and the image intensifier. It is used to compensate for the residual aberrations generated by the correction lens group, thereby achieving the function of compensating for aberrations across the entire spectrum.

[0014] Furthermore, the first positive lens is a biconvex positive lens; the first negative lens is a biconcave negative lens; the second positive lens is a biconvex positive lens; and the second negative lens is a meniscus negative lens with its convex surface facing the image intensifier.

[0015] Furthermore, the curved prism has an optical power of 0.0049788, a center thickness of 19.2 mm, and an off-axis distance of 20–40 mm;

[0016] The first positive lens has an optical power of 0.00813756 and a center thickness of 14.6 mm;

[0017] The first negative lens has an optical power of -0.1142765 and a center thickness of 5mm;

[0018] The second positive lens has an optical power of 0.00788545 and a center thickness of 11 mm;

[0019] The second negative lens has an optical power of -0.00132148 and a center thickness of 2.9 mm.

[0020] Furthermore, the curved prism is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996;

[0021] The first positive lens is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996;

[0022] The first negative lens is made of optical glass with a refractive index of 1.4585 and an Abbe number of 67.821;

[0023] The second positive lens is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996;

[0024] The second negative lens is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996.

[0025] Furthermore, the planar grating is an ultraviolet-visible planar grating with a scribe line density of [missing information].

[0026] With a spectral resolution of 600–1200 lp / mm and a blaze angle of 7°, the system achieves good spectral resolution.

[0027] Furthermore, the slit width is 40 μm, which can effectively suppress the aliasing of the optical image.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. The present invention provides an ultra-high-speed collisional flash spectral detection system based on an image intensifier, comprising a slit, a first folded-axis mirror, a curved prism, a second folded-axis mirror, a correction mirror group, and a planar grating arranged sequentially along the optical path, and an image intensifier. The correction mirror group is an optical multiplexing lens group, comprising a first positive lens, a first negative lens, and a second positive lens arranged sequentially. The first positive lens, the first negative lens, and the second positive lens form a collimating lens group along the incident light path and an imaging lens group along the reflected light path. The overall system structure is relatively compact. By combining the correction mirror group with the curved prism, the system's sagittal astigmatism is significantly reduced, thereby enhancing the concentration of the system's blur spot.

[0030] 2. The ultra-high-speed collision flash spectral detection system based on an image intensifier of the present invention also includes a second negative lens, which is located between the curved prism and the image intensifier, and is used to compensate for the residual aberrations generated by the correction lens group, thereby converging light of different wavelengths onto the image intensifier and improving the detection sensitivity.

[0031] 3. The ultra-high-speed collision flash spectral detection system based on an image intensifier of the present invention has a simple overall assembly process and no special requirements for the spacing and relative position between the optical elements, only the assembly process needs to be met.

[0032] 4. The relative aperture of the ultra-high-speed collisional flash spectral detection system based on the image intensifier of the present invention is 1 / 3. The large relative aperture design improves the light collection capability of the spectral module, thereby improving the signal-to-noise ratio of the system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of an embodiment of an ultra-high-speed collisional flash spectral detection system based on an image intensifier according to the present invention;

[0034] Figure 2 This is a spectral resolution diagram of an embodiment of an ultra-high-speed collisional flash spectral detection system based on an image intensifier according to the present invention;

[0035] Figure 3 This is a schematic diagram of the grating diffraction efficiency of an embodiment of an ultra-high-speed collisional flash spectral detection system based on an image intensifier according to the present invention.

[0036] The attached figures are labeled as follows:

[0037] 1-Slit, 2-First folding mirror, 3-Curved prism, 4-Second folding mirror, 5-Correcting mirror group, 51-First positive lens, 52-First negative lens, 53-Second positive lens, 6-Planar grating, 7-Second negative lens, 8-Image intensifier. Detailed Implementation

[0038] The design concept of this invention is to effectively correct the sagittal astigmatism of the system by combining the Littrow optical model (i.e., the correction mirror group 5) with the curved prism 3, thereby achieving a large relative aperture, high resolution, high signal-to-noise ratio, and lightweight miniaturized design. This invention primarily utilizes spectral characteristics to detect the flash features generated by object collisions, and can be applied to inferring important information such as the early crater formation process of collisions, the material composition of collision materials, the evolution of radiation sources, and related fields of plasma phenomena generated by collisions.

[0039] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. The accompanying drawings are in a simplified form and use non-precise proportions, and are only used to facilitate and clarify the purpose of illustrating the embodiments of the present invention. It should be noted that the terms "first", "second", etc. used in the present invention are only used for descriptive purposes and should not be construed as indicating or implying relative importance.

[0040] like Figure 1 As shown, the present invention provides an ultra-high-speed collision flash spectral detection system based on an image intensifier, comprising a slit 1, a first folding mirror 2, a curved prism 3, a second folding mirror 4, a correction mirror group 5, and a planar grating 6 arranged sequentially along the optical path, as well as a compensation mirror group and an image intensifier 8.

[0041] Slit 1 serves as the object surface of the spectral module, primarily used to limit the incident light energy and spectral sampling interval of the spectrometer. The width of slit 1 is set according to implementation requirements; in this embodiment, the width of slit 1 is 40 μm. After passing through slit 1, the incident light is reflected by the first folding mirror 2 to the curved prism 3, and then transmitted through the curved prism 3 to the second folding mirror 4.

[0042] The curved prism 3 is a plano-convex off-axis positive lens, with its planar side close to the curved prism 3 and its convex side close to the second folding mirror 4. Its main function is to utilize its asymmetry to correct the astigmatism of the system, thereby enhancing the concentration of the system's speckle. In this embodiment, the optical power of the curved prism 3 is 0.0049788, its center thickness is 19.2 mm, and its off-axis distance is 20–40 mm. Too small an off-axis distance will cause interference between the first folding mirror 2 and the compensating mirror group; too large an off-axis distance, while solving the interference problem, will introduce additional off-axis astigmatism into the system, affecting instrument performance. The selection of the off-axis distance of the curved prism 3 in this invention is based on a comprehensive consideration of factors such as the design difficulty and engineering feasibility of the system. In this embodiment, the curved prism 3 is made of optical glass with a refractive index nd1 = 1.4338 and an Abbe number vd1 = 94.996.

[0043] In this embodiment, both the first folding mirror 2 and the second folding mirror 4 are plane mirrors. The plane of the first folding mirror 2 forms a 45° angle with the optical axis of the incident light, mainly folding the optical path between the slit 1 and the curved prism 3 to avoid interference between the spatial positions of the slit 1 and the image intensifier 8. The plane of the second folding mirror 4 is parallel to the plane of the first folding mirror 2, mainly folding the optical path between the curved prism 3 and the correction mirror group 5, making the spatial layout of the system more compact.

[0044] The correction lens group 5 is an optical multiplexing lens group and is the core component of this system. It is located on the reflected light path of the second folding mirror 4. The correction lens group 5 includes a first positive lens 51, a first negative lens 52, and a second positive lens 53 arranged sequentially. The first positive lens 51, the first negative lens 52, and the second positive lens 53 form a collimating lens group along the incident light path and an imaging lens group along the reflected light path. This invention utilizes the combination of the correction lens group 5 and the curved prism 3 to significantly reduce the sagittal astigmatism of the system, thereby enhancing the concentration of the system's blur spot.

[0045] In this embodiment, the first positive lens 51 is a biconvex positive lens with an optical power of 0.00813756 and a center thickness of 14.6 mm; and it is made of optical glass with a refractive index nd2 = 1.4338 and an Abbe number vd2 = 94.996.

[0046] The first negative lens 52 is a biconcave negative lens with an optical power of -0.1142765 and a center thickness of 5mm; it is made of optical glass with a refractive index nd3 = 1.4585 and an Abbe number vd3 = 67.821.

[0047] The second positive lens 53 is a biconvex positive lens with an optical power of 0.00788545 and a center thickness of 11 mm; it is made of optical glass with a refractive index nd4 = 1.4338 and an Abbe number vd4 = 94.996. The optical glass used for the above lenses can be OH quartz or ultraviolet calcium fluoride, which have superior overall performance.

[0048] The planar grating 6 is an ultraviolet-visible planar grating located on the side of the transmission path of the collimating lens group closer to the second positive lens 53. It is used to disperse the light beam passing through the collimating lens group, thereby meeting the system's dispersion rate requirements. In this embodiment, the planar grating 6 has a line density of 600–1200 lp / mm and a blaze angle of 7°. A higher line density results in higher spectral resolution, and the blaze angle determines the blaze efficiency of the grating; this blaze angle is closely related to the selection of the blaze wavelength.

[0049] The image intensifier 8 is located on the side of the curved prism 3 near the first folded-axis mirror 2. The light signal dispersed by the planar grating 6 is transmitted through the imaging lens group, reflected by the second folded-axis mirror 4, and converged by the curved prism 3 before entering the image intensifier 8. The image intensifier 8 is used to amplify the converged light signal, thereby enhancing the detection sensitivity of the system.

[0050] The compensating lens group consists of a second negative lens 7, located between the curved prism 3 and the image intensifier 8. It compensates for the residual aberrations produced by the correcting lens group 5, providing full-spectrum aberration compensation. The second negative lens 7 is a meniscus negative lens with its convex surface facing the image intensifier 8. It has an optical power of -0.00132148, a center thickness of 2.9 mm, and is made of optical glass with a refractive index nd5 = 1.4338 and an Abbe number vd5 = 94.996.

[0051] The system operates as follows: the optical path passes through slit 1, is reflected by the first folding mirror 2, enters the curved prism 3, and is then reflected by the second folding mirror 4 into the correction mirror group 5. The correction mirror group 5 collimates the incident beam, which is then incident on the planar grating 6. After diffraction by the planar grating 6, the diffracted beam is converged again by the correction mirror group 5. The converged beam is then reflected again by the second folding mirror 4, and the reflected light is again incident on the curved prism 3. The converged beam after passing through the curved prism 3 undergoes residual aberration compensation by the compensation mirror group, thereby converging light of different wavelengths onto the image intensifier 8 for amplification and enhancement of the optical signal, thus realizing ultra-high-speed collision flash spectral detection based on the image intensifier.

[0052] like Figure 2 As shown, the sampling resolution of this system can meet the spectral resolution requirement of 0.9 nm.

[0053] like Figure 3As shown, the grating of this system has relatively high diffraction efficiency in the wavelength range of 300nm to 500nm.

[0054] Although embodiments of the present invention have been shown and described above, those skilled in the art should consider any variations and modifications of the above embodiments that fall within the scope of the present invention's spirit and essence to be within the protection scope of the present invention.

Claims

1. A high-speed collisional flash spectral detection system based on an image intensifier, characterized in that: It includes a slit (1), a first folding mirror (2), a curved prism (3), a second folding mirror (4), a correction mirror group (5), and a planar grating (6) arranged sequentially along the optical path, as well as an image intensifier (8); The slit (1) is used to limit the incident light energy and spectral sampling interval. After the incident light passes through the slit (1), it is reflected by the first folding mirror (2) to the curved prism (3), and then transmitted through the curved prism (3) to the second folding mirror (4). The curved prism (3) is a plano-convex off-axis positive lens, with its planar side close to the curved prism (3) and its convex side close to the second folding mirror (4). The first folding mirror (2) and the second folding mirror (4) are both plane mirrors. The plane where the first folding mirror (2) is located forms a 45° angle with the optical axis of the incident light, and the plane where the second folding mirror (4) is located is parallel to the plane where the first folding mirror (2) is located. The correction lens group (5) is an optical multiplexing lens group, which is located on the reflected light path of the second folding mirror (4); the correction lens group (5) includes a first positive lens (51), a first negative lens (52) and a second positive lens (53) arranged in sequence; the first positive lens (51), the first negative lens (52) and the second positive lens (53) form a collimating lens group along the incident light path and an imaging lens group along the reflected light path; The planar grating (6) is located on the side of the transmission path of the collimating lens group closer to the second positive lens (53), and is used to disperse the light beam passing through the collimating lens group; The dispersed light signal is transmitted through the imaging lens group, reflected by the second folding mirror (4), and converged by the curved prism (3) before entering the image intensifier (8); The image intensifier (8) is located on the side of the curved prism (3) near the first folded-axis mirror (2) and is used to amplify the converging light signal, thereby enhancing the detection sensitivity of the system.

2. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 1, characterized in that: It also includes a compensation lens group, which is a second negative lens (7) located between the curved prism (3) and the image intensifier (8) to compensate for the residual aberrations generated by the correction lens group (5).

3. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 2, characterized in that: The first positive lens (51) is a biconvex positive lens; The first negative lens (52) is a double concave negative lens; The second positive lens (53) is a biconvex positive lens; The second negative lens (7) is a meniscus negative lens with its convex surface facing the image intensifier (8).

4. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 3, characterized in that: The curved prism (3) has an optical power of 0.0049788, a center thickness of 19.2 mm, and an off-axis distance of 20–40 mm. The first positive lens (51) has an optical power of 0.00813756 and a center thickness of 14.6 mm; The first negative lens (52) has an optical power of -0.1142765 and a center thickness of 5 mm; The second positive lens (53) has an optical power of 0.00788545 and a center thickness of 11 mm; The second negative lens (7) has an optical power of -0.00132148 and a center thickness of 2.9 mm.

5. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 4, characterized in that: The curved prism (3) is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996; The first positive lens (51) is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996; The first negative lens (52) is made of optical glass with a refractive index of 1.4585 and an Abbe number of 67.821; The second positive lens (53) is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.996; The second negative lens (7) is made of optical glass with a refractive index of 1.4338 and an Abbe number of 94.

996.

6. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 5, characterized in that: The planar grating (6) is an ultraviolet-visible planar grating with a line density of 600-1200 lp / mm and a blaze angle of 7°.

7. The ultra-high-speed collisional flash spectral detection system based on an image intensifier according to claim 6, characterized in that: The width of the slit (1) is 40 μm.

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