Large-relative-aperture athermalization near-infrared optical lens for Raman spectrum analyzer
By designing a large relative aperture near-infrared optical lens to eliminate thermal differences, the shortcomings of Raman spectroscopy analyzer optical lenses in terms of energy harvesting and thermal stability are solved, achieving high spectral resolution and imaging quality over a wide temperature range, making it suitable for Raman spectroscopy analyzers.
Patent Information
- Application Number
- CN202422688863.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-11-21
- Estimated Expiration
- 2034-11-05
AI Technical Summary
Existing Raman spectrometers have shortcomings in terms of energy harvesting and thermal stability, resulting in weak light intensity and sensitivity to temperature changes, making it difficult to maintain good spectral resolution and imaging quality at different temperatures.
A large relative aperture pyrometric near-infrared optical lens was designed, employing a Litterow structure including multiple lenses and a reflective grating. By optimizing the lens spacing and materials, high spectral resolution and imaging quality were achieved over a wide temperature range.
It achieves high spectral resolution and imaging quality within a temperature range of 5-35℃. The lens is compact, highly adaptable, and can maintain stable spectral resolution and imaging effects at different temperatures.
Smart Images
Figure CN223582228U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to raman spectrum analyzer technical field, especially a kind of for raman spectrum analyzer big relative aperture heat error near-infrared optical lens. BACKGROUND
[0002] Raman spectrum analyzer can provide fast, simple, repeatable, non-destructive qualitative and quantitative analysis, it does not need sample preparation, can be directly measured by fiber probe or through glass, quartz and optical fiber. It has important significance for gem and mineral identification, liquor component analysis and other industries.
[0003] The core of raman spectrum analyzer is optical lens, and the existing optical lens still has the following defects:
[0004] 1. Energy: Raman spectrum is scattering spectrum, and light intensity is very weak. In order to accurately distinguish the spectral lines in the working area, the light energy collection capability of the optical system needs to be strong, and a large relative aperture is required.
[0005] 2. Thermal stability: the environmental temperature changes greatly during the use of raman spectrometer, and the existing optical lens is very sensitive to temperature change. The image surface spot quality changes with temperature. In order to obtain good results at different temperatures, the optical system needs to be heat error. INVENTION CONTENTS
[0006] To solve the above technical problems, one technical scheme of the utility model is as follows:
[0007] Provided is a large relative aperture heat error near-infrared optical lens for raman spectrum analyzer, which comprises: an image plane, a reflecting mirror, a positive crescent first lens, a positive crescent second lens, a negative crescent third lens, a negative crescent fourth lens, a negative crescent fifth lens and a reflecting grating arranged in sequence from right to left, and the positive crescent first lens, the positive crescent second lens, the negative crescent third lens, the negative crescent fourth lens, the negative crescent fifth lens and the reflecting grating are coaxially arranged, and the image plane is on the focal plane of the lens,
[0008] The curvature radius of the negative crescent S2 surface of the negative crescent fifth lens is-45, the curvature radius of the negative crescent S3 surface is-230, the distance between the reflecting grating S1 surface and the negative crescent S2 surface is 35 mm, and the distance between the negative crescent S2 surface and the negative crescent S3 surface is 4 mm. In the present case, the distance between the centers of each surface is, for example: the distance between the center of the reflecting grating S1 surface and the center of the negative crescent S2 surface is 35 mm, and the distance between the center of the negative crescent S2 surface and the center of the negative crescent S3 surface is 4 mm.
[0009] The curvature radius of the negative crescent S4 face of the negative crescent fourth lens is -150, the curvature radius of the negative crescent S5 face is -70, the interval between the negative crescent S4 face and the negative crescent S3 face is 9 mm, and the interval between the negative crescent S4 face and the negative crescent S5 face is 18 mm.
[0010] The curvature radius of the positive crescent S6 face of the negative crescent third lens is 600, the curvature radius of the negative crescent S7 face is -90, the interval between the positive crescent S6 face and the negative crescent S5 face is 3 mm, and the interval between the positive crescent S6 face and the negative crescent S7 face is 9 mm.
[0011] The curvature radius of the positive crescent S8 face of the positive crescent second lens is 100, the curvature radius of the positive crescent S9 face is 480, the interval between the positive crescent S8 face and the negative crescent S7 face is 13 mm, and the interval between the positive crescent S8 face and the positive crescent S9 face is 16 mm.
[0012] The curvature radius of the positive crescent S10 face of the positive crescent first lens is 45, the curvature radius of the positive crescent S11 face is 60, the interval between the positive crescent S10 face and the positive crescent S9 face is 12 mm, the interval between the positive crescent S10 face and the positive crescent S11 face is 14 mm, and the interval between the positive crescent S11 face and the image plane is 48 mm.
[0013] In a preferred embodiment of the present application, the interval between the image plane and the reflecting mirror is 28 mm.
[0014] In a preferred embodiment of the present application, the interval between the reflecting mirror and the first lens is 20 mm.
[0015] In a preferred embodiment of the present application, the line pair number of the reflecting S1 face of the reflecting grating is 630 lp / mm, and the diffraction order is +1 order.
[0016] In a preferred embodiment of the present application, the material of the positive crescent first lens is glass H-LAK53B.
[0017] In a preferred embodiment of the present application, the materials of the positive crescent second lens, the negative crescent third lens and the negative crescent fourth lens are glass H-LAK2A.
[0018] In a preferred embodiment of the present application, the material of the negative crescent fifth lens is glass H-ZF52.
[0019] In a preferred embodiment of the present application, the working temperature of the optical lens is 5-35 DEG C.
[0020] The utility model discloses beneficial effect is: through the layout and the improvement of lens, reflector and reflection grating, realized the infrared optical lens of big relative aperture, and heat absorption difference effect is good, can improve the spectral resolution and imaging quality of lens in larger temperature range, and the volume is small, and the versatility is strong. BRIEF DESCRIPTION OF DRAWINGS
[0021] In order to more clearly illustrate the technical scheme in the utility model embodiment, the following will be to the drawing needed to be used in the embodiment description briefly introduced, obviously, the drawing in the following description only some embodiments of the utility model, for ordinary skilled person in the art, under the premise of not paying creative labor, can also obtain other drawings according to these drawings, wherein:
[0022] Figure 1 It is a kind of structure schematic diagram for the big relative aperture heat absorption difference near-infrared optical lens of raman spectrum analyzer of the utility model one preferable embodiment;
[0023] Figure 2 It is the optical transfer function (MTF) diagram of the utility model under 20 DEG C and the working wavelength 790nm;
[0024] Figure 3 It is the optical transfer function (MTF) diagram of the utility model under 20 DEG C and the working wavelength 825nm;
[0025] Figure 4 It is the optical transfer function (MTF) diagram of the utility model under 20 DEG C and the working wavelength 935nm;
[0026] Figure 5 It is the optical transfer function (MTF) diagram of the utility model under 20 DEG C and the working wavelength 1080nm;
[0027] Figure 6 It is the optical transfer function (MTF) diagram of the utility model under 5 DEG C and the working wavelength 790nm;
[0028] Figure 7 It is the optical transfer function (MTF) diagram of the utility model under 5 DEG C and the working wavelength 825nm;
[0029] Figure 8 It is the optical transfer function (MTF) diagram of the utility model under 5 DEG C and the working wavelength 935nm;
[0030] Figure 9 It is the optical transfer function (MTF) diagram of the utility model under 5 DEG C and the working wavelength 1080nm;
[0031] Figure 10The optical transfer function (MTF) graph of the utility model under 35 DEG C and working wavelength 790nm is:
[0032] Figure 11 The optical transfer function (MTF) graph of the utility model under 35 DEG C and working wavelength 825nm is:
[0033] Figure 12 The optical transfer function (MTF) graph of the utility model under 35 DEG C and working wavelength 935nm is:
[0034] Figure 13 The optical transfer function (MTF) graph of the utility model under 35 DEG C and working wavelength 1080nm is:
[0035] Figure 14 The field curvature and distortion graph of the utility model under 5 DEG C scene is:
[0036] Figure 15 The field curvature and distortion graph of the utility model under 20 DEG C scene is:
[0037] Figure 16 The field curvature and distortion graph of the utility model under 35 DEG C scene is. DETAILED DESCRIPTION
[0038] The technical scheme in the embodiments of the utility model will be described clearly and completely below, obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by the person skilled in the art without making creative labor belong to the range of protection of the utility model.
[0039] Please refer to Figures 1-16 , the utility model embodiment includes:
[0040] A large relative aperture athermal near-infrared optical lens for Raman spectrum analyzer adopts Littrow structure, and its structure includes: image plane 8, mirror 1, positive crescent first lens 2, positive crescent second lens 3, negative crescent third lens 4, negative crescent fourth lens 5, negative crescent fifth lens 6 and reflecting grating 7 are sequentially arranged from right to left, and the positive crescent first lens 2, the positive crescent second lens 3, the negative crescent third lens 4, the negative crescent fourth lens 5, the negative crescent fifth lens 6 and the reflecting grating 7 are coaxially arranged, and the image plane 8 is on the focal plane of the lens.
[0041] After the light is emitted, it is firstly reflected by the mirror 1 to the lens group, and then propagates through the positive meniscus first lens 2, the positive meniscus second lens 3, the negative meniscus third lens 4, the negative meniscus fourth lens 5, the negative meniscus fifth lens 6 in turn, and then propagates through the negative meniscus fifth lens 6, the negative meniscus fourth lens 5, the negative meniscus third lens 4, the positive meniscus second lens 3, the positive meniscus first lens 2 in turn after being reflected by the reflection grating 7, and finally forms an image on the image plane 8.
[0042] Further preferably, the inclination angle of the mirror can be adjusted according to the angle of the light source in front of the mirror, the distance between the image plane 8 and the mirror 1 is 30 mm, and the distance between the mirror and the first lens is 15 mm, and the above distances can be finely adjusted according to the target size of the focus point on the image plane to meet different requirements.
[0043] Referring to Figure 1 The parameters of the positive meniscus first lens 2, the positive meniscus second lens 3, the negative meniscus third lens 4, the negative meniscus fourth lens 5, the negative meniscus fifth lens 6, the reflection grating 7 and the image plane 8 are shown in Table 1, wherein the reflection grating is the first surface and the image plane is the last surface from left to right.
[0044]
[0045] The parameters of the reflection grating 7 are shown in Table 2.
[0046]
[0047] The optical parameters of the lens are shown in Table 3 below.
[0048]
[0049] Figure 2 , Figure 3 , Figure 4 , Figure 5 The optical transfer function (OTF) diagram of the optical lens at each working wavelength when the temperature is 20℃.
[0050] When the working wavelength is 790 nm, the OTF modulus is greater than 0.7 at the Nyquist frequency; when the working wavelength is 825 nm, the OTF modulus is greater than 0.8 at the Nyquist frequency; when the working wavelength is 935 nm, the OTF modulus is greater than 0.65 at the Nyquist frequency; and when the working wavelength is 1080 nm, the OTF modulus is greater than 0.55 at the Nyquist frequency.
[0051] Figure 6 , Figure 7 , Figure 8 , Figure 9 The optical transfer function (OTF) diagram of the optical lens at each working wavelength when the temperature is 5℃.
[0052] When the working wavelength is 790nm, the OTF modulus is greater than 0.6 at the Nyquist frequency; when the working wavelength is 825, the OTF modulus is greater than 0.75 at the Nyquist frequency; when the working wavelength is 935nm, the OTF modulus is greater than 0.65 at the Nyquist frequency; when the working wavelength is 1080nm, the OTF modulus is greater than 0.5 at the Nyquist frequency.
[0053] Figure 10 、 Figure 11 、 Figure 12 、 Figure 13 The optical transfer function (MTF) diagram of the optical lens at each working wavelength is 35℃.
[0054] When the working wavelength is 790nm, the OTF modulus is greater than 0.7 at the Nyquist frequency; when the working wavelength is 825, the OTF modulus is greater than 0.8 at the Nyquist frequency; when the working wavelength is 935nm, the OTF modulus is greater than 0.6 at the Nyquist frequency; when the working wavelength is 1080nm, the OTF modulus is greater than 0.6 at the Nyquist frequency.
[0055] According to the above, the MTF curve of the lens in the working temperature range is greater than 0.5 at the Nyquist frequency, which meets the requirements of athermalization and meets the needs of a spectral system.
[0056] Figure 14 、 Figure 15 、 Figure 16 The field curvature distortion diagram of the optical system at each working wavelength is 20℃, 5℃, 35℃.
[0057] Therefore, the optical lens can maintain good athermalization effect in a larger temperature range, and can effectively improve the spectral resolution and imaging quality of the lens.
[0058] The utility model relates to a big relative aperture athermalization near infrared optical lens for raman spectrum analyzer has the beneficial effect that:
[0059] 1. Adopt big relative aperture lens, even when the intensity of raman spectrum is very weak, can also collect enough energy, improve the imaging quality;
[0060] 2. Can accurately distinguish spectral line, a plurality of characteristic wavelength difference only a few nanometers of the target to be measured can also be applicable, improve the spectral resolution and versatility of the lens, effectively improve the precision of analysis and detection;
[0061] 3. Good non-thermal performance, so that the lens is not sensitive to temperature changes, without focusing in a large temperature range, improve the performance of the lens, meet the different requirements of the use of monitoring;
[0062] 4. By setting the lens structure and material reasonably, the volume of the lens can be reduced, and the applicability is improved.
[0063] The above only describes the embodiments of the present application, and does not limit the patent range of the present application, and any equivalent structure or equivalent process transformation made by using the content of the present application specification, or direct or indirect application in other related technical fields, are also included in the patent protection range of the present application.
Claims
1. A large relative aperture athermal near-infrared optical lens for a Raman spectrometer, characterized in that, Comprise: The image plane, the mirror, the positive first lens, the positive second lens, the negative third lens, the negative fourth lens, the negative fifth lens and the reflection grating are arranged in sequence from right to left, and the positive first lens, the positive second lens, the negative third lens, the negative fourth lens, the negative fifth lens and the reflection grating are coaxially arranged, and the image plane is on the focal plane of the lens, The curvature radius of the negative S2 surface of the negative fifth lens is -45 mm, the curvature radius of the negative S3 surface is -230 mm, the distance between the reflection S1 surface and the negative S2 surface is 35 mm, and the distance between the negative S2 surface and the negative S3 surface is 4 mm; The curvature radius of the negative S4 surface of the negative fourth lens is -150 mm, the curvature radius of the negative S5 surface is -70 mm, the distance between the negative S4 surface and the negative S3 surface is 9 mm, and the distance between the negative S4 surface and the negative S5 surface is 18 mm; The curvature radius of the positive S6 surface of the negative third lens is 600 mm, the curvature radius of the negative S7 surface is -90 mm, the distance between the positive S6 surface and the negative S5 surface is 3 mm, and the distance between the positive S6 surface and the negative S7 surface is 9 mm; The curvature radius of the positive S8 surface of the positive second lens is 100 mm, the curvature radius of the positive S9 surface is 480 mm, the distance between the positive S8 surface and the negative S7 surface is 13 mm, and the distance between the positive S8 surface and the positive S9 surface is 16 mm; The curvature radius of the positive S10 surface of the positive first lens is 45 mm, the curvature radius of the positive S11 surface is 60 mm, the distance between the positive S10 surface and the positive S9 surface is 12 mm, the distance between the positive S10 surface and the positive S11 surface is 14 mm, and the distance between the positive S11 surface and the image plane is 48 mm.
2. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer according to claim 1, wherein, The distance between the image plane and the mirror is 28 mm.
3. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The distance between the mirror and the first lens is 20 mm.
4. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The line pair number of the reflection S1 surface of the reflection grating is 630 lp / mm, and the diffraction order is +1 order.
5. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The material of the positive first lens is glass H-LAK53B.
6. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The materials of the positive second lens, the negative third lens and the negative fourth lens are glass H-LAK2A.
7. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The material of the negative fifth lens is glass H-ZF52.
8. The large relative aperture athermal near-infrared optical lens for a Raman spectrometer of claim 1, wherein, The working temperature of the optical lens is 5-35 DEG C.