Light path system and anastigmatic echelle spectrometer

Abstract

The utility model discloses a light path system and an anastigmatic echelle spectrometer, which are used in the technical field of spectrometers. The optical path system includes: a slit configured to receive a light source beam; a collimator configured to receive the light beam from the slit; a diffraction assembly configured to receive the light beam from the collimator and generate diffracted light; the aspheric reflector is configured to receive the diffracted light from the diffraction assembly and focus the diffracted light; a detector configured to receive the focused light from the aspheric reflector; a light path between the aspheric reflector and the detector, a light path between the collimator and the diffraction assembly and / or a light path between the collimator and the slit form a crossed light path. According to the optical path system, the aspheric reflector and the cross optical path are combined, so that the aberration elimination capability of the whole optical path system breaks through the order of magnitude of 40 microns, the whole optical path structure is more compact, and the problems of redundant structure and insufficient astigmatism elimination capability of an optical system in the prior art are practically solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of spectrometer especially relates to a light path system and eliminate image difference middle echelon spectrometer. BACKGROUND

[0002] Inductively coupled plasma atomic emission spectrum analysis technology is one of the element analysis methods in the material field; the spectral range, spectral resolution, sensitivity, and detection limit of the testing instrument are very strict; the middle echelon grating spectrometer is a new type of high-resolution and high-precision spectral instrument; it uses a middle echelon grating as a main dispersion element, forms a two-dimensional overlapping spectrum on the image plane after prism transverse dispersion, has the advantages of high resolution, wide band, small size, and is widely used in the detection of inductively coupled plasma atomic emission spectrum.

[0003] In the spectrometer technology, eliminating image difference is an important research topic, at present, researchers find that the light path of eliminating image difference has the problems of complex structure and insufficient image difference elimination capability, which can be specifically manifested as follows: some technologies use aspheric mirrors to eliminate image difference, such as a spectrometer (application number US11009397B2) disclosed by the prior art, which uses mirrors, prisms, diffraction gratings, lenses, aspheric mirrors and two-dimensional sensors to eliminate image difference, however, the overall light path structure is M-shaped light path structure, which has a simple one-way light path or fixed-angle light path structure, and the image difference needs to be adjusted and compensated by the aspheric mirror and other optical components after the image difference is generated, which is complex in structure; some technologies use cross light paths to eliminate image difference, such as a cross-type image difference elimination structure spectrometer design disclosed by the prior art, which designs a cross-type CT light path structure to eliminate image difference, and the image difference elimination capability achieved by the structure is on the order of 60μm, but the image difference elimination capability cannot be broken through to the order of 40μm; at present, there is no technology that combines cross light paths with aspheric mirrors to eliminate image difference. UTILITY MODEL CONTENTS

[0004] The utility model provides a kind of light path system and eliminate image difference middle echelon spectrometer, to solve the problems of complex structure and insufficient image difference elimination capability of prior art optical system.

[0005] The utility model provides a kind of light path system in the first aspect, comprising:

[0006] Slit is configured to receive light beam of light source;

[0007] Collimator is configured to receive light beam from the slit;

[0008] Diffractive component is configured to receive light beam from the collimator, and generates diffractive light;

[0009] a non-spherical mirror configured to receive the diffracted light from the diffraction component and focus the diffracted light;

[0010] a detector configured to receive the focused light from the non-spherical mirror;

[0011] wherein the optical path between the non-spherical mirror and the detector intersects the optical path between the collimator and the diffraction component and / or the optical path between the collimator and the slit.

[0012] In some embodiments of the first aspect, the slit, the collimator, the diffraction component, the non-spherical mirror and the detector are arranged in a coplanar manner.

[0013] In some embodiments of the first aspect, the non-spherical mirror has a conic constant of -10 to 1.

[0014] In some embodiments of the first aspect, the collimator has a focal length within a same preset range as a focal length of the non-spherical mirror.

[0015] In some embodiments of the first aspect, the collimator is a concave spherical mirror.

[0016] In some embodiments of the first aspect, the diffraction component comprises a prism and a step grating;

[0017] the prism is configured to receive the light beam from the collimator and receive the diffracted light from the step grating;

[0018] the step grating is configured to receive the light beam from the prism and generate the diffracted light, and direct the diffracted light to the prism.

[0019] In some embodiments of the first aspect, a surface of the step grating is coated with a reflective film.

[0020] In some embodiments of the first aspect, the prism is a wedge prism, and the wedge angle of the wedge prism is 8 to 15°.

[0021] In some embodiments of the first aspect, the step grating has a grating line number of 50 to 100 lines, and an optical path incident angle of the step grating is configured to be 50 to 70°.

[0022] In some embodiments of the first aspect, the slit is a size-adjustable slit structure.

[0023] The second aspect of the utility model provides a step spectrum instrument of astigmatism elimination, comprising the optical path system of first aspect.

[0024] From the above technical scheme, the utility model has the following advantages:

[0025] The embodiment provides an optical path system, since the aspheric mirror is arranged in the optical path system, the aspheric mirror focuses the received diffraction light into a detector, so that the aspheric mirror can compensate the split diffraction light in the optical path process, the aspheric mirror adjusts the corresponding and appropriate focusing of light rays of different wavelengths on a meridional plane and a sagittal plane, compensates the focusing difference of light rays in different directions, and makes the light rays in different directions converge to the detector accurately, so that astigmatism is effectively reduced; and since the optical path between the aspheric mirror and the detector intersects with the optical path between the collimator and the diffraction component and / or the optical path between the collimator and the slit, the outgoing light path of the aspheric mirror enters the path intersecting with the previous optical path, the intersecting path can change the propagation direction of the light rays, guide the light rays to propagate in different planes and angles, and change the refraction or reflection of the light rays on the meridional plane and the sagittal plane, so that the light rays are focused and the astigmatism is eliminated; in combination, the astigmatism elimination capability of the whole optical path system breaks through to the order of 40 μm, the astigmatism elimination capability is strong, the overall size of the optical path is small, the optical components used are few, the structure is more compact, and the problems of the complex structure of the optical system and the insufficient astigmatism elimination capability of the prior art are solved. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical scheme in the embodiments of the present application or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0027] Figure 1 The structure schematic diagram of the optical path system provided by the embodiment of the present application is shown in the figure.

[0028] Figure 2 The structure schematic diagram of the optical path system provided by the comparative example one of the present application is shown in the figure.

[0029] Figure 3 The optical point list diagram provided by the comparative example one of the present application is shown in the figure.

[0030] Figure 4 The optical point list diagram provided by the embodiment one of the present application is shown in the figure.

[0031] Reference signs:

[0032] 1, slit; 2, collimator; 3, diffraction component; 30, prism; 31, echelle grating; 4, aspheric mirror; 5, detector. DETAILED DESCRIPTION

[0033] The utility model discloses an optical path system and a novel echelle spectrometer of astigmatism elimination, which is used to solve the technical problem of the complex structure and insufficient astigmatism elimination capability of the prior art optical system.

[0034] In order to make the utility model's utility model purpose, feature, advantage can be more obvious and easy to understand, below will combine the drawings in the utility model embodiment, to the technical scheme in the utility model embodiment, clear, complete description, obviously, the following described embodiment is only a part of the embodiment of the utility model, but not all the embodiment. Based on the embodiment in the utility model, all other embodiments obtained by the ordinary skill in the art without making creative labor are within the scope of the utility model protection.

[0035] Please refer to Figure 1 The utility model provides an optical path system, comprising:

[0036] The slit 1 is configured to receive the light beam of the light source;

[0037] The collimator 2 is configured to receive the light beam from the slit 1;

[0038] The diffraction component 3 is configured to receive the light beam from the collimator 2 and generate diffracted light;

[0039] The aspheric mirror 4 is configured to receive the diffracted light from the diffraction component 3 and focus the diffracted light;

[0040] The detector 5 is configured to receive the focused light from the aspheric mirror 4;

[0041] The optical path between the aspheric mirror 4 and the detector 5 intersects the optical path between the collimator 2 and the diffraction component 3 and / or the optical path between the collimator 2 and the slit 1.

[0042] In the working process of the embodiment, the light beam of the light source passes through the slit 1, and the light beam becomes a light beam with a required angle after passing through the slit 1 and is directed to the collimator 2; the collimator 2 receives the light beam and converts it into collimated light and directs it to the diffraction component 3; the diffraction component 3 receives the collimated light beam and diffracts it, generates diffracted light and directs it to the aspheric mirror 4; the aspheric mirror 4 receives the diffracted light and focuses it and directs it to the detector 5; on the exit light path of the aspheric mirror 4, the exit light path intersects the previous light path; finally, the detector 5 receives the focused light beam of the aspheric mirror 4 and obtains the light spot to be measured.

[0043] From the above process, the slit 1 is used to screen the light entering the optical path system, reducing stray light interference; the collimator 2 controls the direction of the light beam, so that the light enters the subsequent optical elements in a more regular manner for astigmatism correction; the diffraction assembly 3 can diffract light of different wavelengths in different directions, that is, the originally chaotic light beam is redirected according to different wavelengths; the aspheric mirror 4 can compensate for the light of different wavelengths after diffraction, that is, the aspheric mirror 4 respectively adjusts the focus of the light of different wavelengths in the meridional plane and the sagittal plane, so that the imaging is effectively corrected; the exit light path of the aspheric mirror 4 intersects with the previous light path. This kind of intersecting path can change the propagation direction of the light, guide the light to propagate in different planes and angles, so as to change the refraction or reflection of the light in the meridional plane and the sagittal plane, so as to focus the light and eliminate astigmatism; finally, different wavelength spectra fall on different positions of the detector 5 in the form of light spots, effectively improving the system resolution.

[0044] Compared with the prior art, the advantages of the embodiment are: first, the astigmatism elimination capability is strong, which can reach the order of 40 μm. The embodiment combines the aspheric mirror 4 and the intersecting light path, so that the light in the meridional plane and the sagittal plane is adjusted and changed, so that the final light can be focused and astigmatism eliminated. Compared with the astigmatism elimination capability of the prior art of the order of 60 μm, the astigmatism elimination capability of the embodiment is significantly improved. Second, the structure is more compact. The embodiment uses the intersecting light path, so the overall size is small, the optical components used are few, and the structure is more compact. It is not necessary to additionally set optical components in front of and behind the aspheric mirror 4 as in the prior art, and it is not necessary to occupy space as in the M-type light path.

[0045] In one specific embodiment, as shown in Figure 1 The arrangement relationship of the optical elements in the optical path system is further provided, that is, the slit 1, the collimator 2, the diffraction assembly 3, the aspheric mirror 4 and the detector 5 are coplanarly arranged, that is, the optical axis of the slit 1, the optical axis of the collimator 2, the optical axis of the diffraction assembly 3, the optical axis of the aspheric mirror 4 and the optical axis of the detector 5 are located on the same vertical plane or the same horizontal plane or the same inclined plane. In specific implementation, the light paths of the optical elements are on the same plane, which has the following advantages: first, the light path can be simplified, and the light path can be adjusted by using the plane geometric relationship, reducing the complex angle and position adjustment or optical element arrangement in three-dimensional space, and simplifying the light path; second, the aberration can be reduced. The reflection and focusing effects of the coplanarly arranged optical elements in the meridional plane and the sagittal plane are the same, which helps to reduce the aberration, thereby improving the clarity and resolution of imaging.

[0046] In one embodiment, the light path between the aspheric mirror 4 and the detector 5 and the light path between the collimator 2 and the diffraction assembly 3 form a coplanarly arranged intersecting light path.

[0047] In an embodiment, the light path between the aspheric mirror 4 and the detector 5 forms a cross light path with the coplanar arrangement of the light paths between the collimator 2 and the diffraction assembly 3 and the light path between the collimator 2 and the slit 1.

[0048] In a specific embodiment, further provided is an implementable structure of the slit 1 for limiting the width and shape of the light beam, which in a specific implementation can control the wavelength range and light intensity of the light entering the instrument, by adjusting the width of the slit 1, light of a specific wavelength range can be selected for analysis, and the interference of stray light can be reduced, and the resolution of the spectrum can be improved.

[0049] In a specific embodiment, as shown in Figure 1 further provided is an implementable structure of the collimator 2 for converting the divergent light beam into a parallel light beam, which in a specific implementation can allow the laser beam to propagate better, reduce beam divergence, and improve energy density.

[0050] In an embodiment, as shown in Figure 1 the collimator 2 is a concave spherical mirror, which in a specific implementation can be used to converge the light passing through the slit 1 so that it enters the subsequent optical elements more regularly for astigmatism correction.

[0051] In the present embodiment, the preset range of the focal length of the concave spherical mirror is 350-400 mm, i.e., the preset range of the focal length of the concave spherical mirror is consistent with that of the aspheric mirror 4 below.

[0052] In a specific embodiment, as shown in Figure 1 further provided is an implementable structure of the diffraction assembly 3, which includes a prism 30 and a stepped grating 31; the prism 30 is configured to receive the light beam from the collimator 2 and receive the diffracted light from the stepped grating 31, i.e., the prism 30 in front of the stepped grating 31 and the prism 30 behind the stepped grating 31 are the same prism 30; the stepped grating 31 is configured to receive the light beam from the prism 30 and generate diffracted light, and guide the diffracted light to the prism 30; in a specific implementation, the front prism 30 receives the light beam from the collimator 2 and performs preliminary correction of astigmatism in the prism 30 to avoid the problem of aberration in a wide wavelength range, and the light passing through the front prism 30 is guided to the stepped grating 31; the stepped grating 31 receives the light from the front prism 30 and then diffracts on the stepped grating 31, and the diffracted light is reflected in a manner that different wavelengths correspond to different diffraction angles, and light of the same wavelength spectrum is parallel light, and the diffracted light is guided to the rear prism 30; the rear prism 30 receives the diffracted light from the stepped grating 31 and further optimizes the astigmatism by means of reverse compensation.

[0053] In an embodiment, as shown in Figure 1As shown, the surface of the echelon grating 31 is coated with a reflective film, and the reflective film is a wide-spectrum reflective film, which refers to an optical thin film that has high reflectivity to light in a relatively wide wavelength range (for example, from the ultraviolet band to the infrared band). In a specific implementation, the echelon grating 31 coated with the wide-spectrum reflective film can diffract light with a wavelength range of 160 nm-900 nm.

[0054] The wide-spectrum reflective film can be a metal material with a wide reflection band, or a dielectric material such as titanium dioxide or silicon dioxide. The film coating method can be physical deposition or chemical deposition, which can be selected by a person skilled in the art according to actual needs.

[0055] In an embodiment, as shown in Figure 1 The grating line number of the echelon grating 31 is 50-100 lines, and the light path incidence angle of the echelon grating 31 is configured to be 50-70°, that is, the angle at which the light incident on the echelon grating 31 from the front prism 30 is 50-70°, and when the grating line number is 50-100 lines, a relatively wide wavelength range can be covered.

[0056] In an embodiment, as shown in Figure 1 The prism 30 is a wedge prism 30, and the wedge angle of the wedge prism 30 is 8-15°. The wedge prism 30 can enhance the light splitting effect and compensate for the light path.

[0057] It should be noted that the prism can also be a doublet prism or an apochromatic prism, which can be selected by a person skilled in the art according to actual needs.

[0058] In a specific embodiment, as shown in Figure 1 The surface shape of the aspheric mirror 4 is a complex curved surface designed according to a predetermined mathematical curve. The curvature of the curved surface is not constant but continuously changes along the surface. In a specific implementation, the aspheric mirror 4 can respectively focus and adjust different wavelengths of light in the meridional plane and the sagittal plane.

[0059] In an embodiment, the conic coefficient of the aspheric mirror 4 is -10-1. In a specific implementation, when the conic coefficient is in this range, the astigmatism generated after focusing the light spot can be reduced or eliminated, so that the light spot is as small as possible, and the resolution of the entire optical path system is improved.

[0060] In an embodiment, as shown in Figure 1As shown, in order to reduce imaging aberration, the focal length of the aspheric mirror 4 is in the same preset range as the focal length of the collimator 2, and the preset range is 350-400 mm. In a specific implementation, the aspheric mirror 4 is configured to focus the diffracted light, and the collimator 2 is configured to reflect the slit 1 light and change it into collimated light. Both of them reflect light, and keeping the same or similar focal length helps to reduce aberration and makes the imaging position, size and light propagation more controllable.

[0061] In this embodiment, the preset range of the focal length of the aspheric mirror 4 is 350-400 mm, that is, the focal length of the aspheric mirror 4 is consistent with the preset range of the focal length of the concave spherical mirror in the foregoing.

[0062] In one specific embodiment, as shown in Figure 1 Further, the achievable structure of the detector 5 is provided, and the detector 5 is a high-sensitivity charge coupled device (CCD), which can convert the detected light signal into an electrical signal, so as to realize data collection.

[0063] The utility model also provides a kind of stigmatic echelle spectrometer, comprising:

[0064] Shell;

[0065] The optical path system of the above embodiment is arranged in the shell.

[0066] In the specific application of this embodiment, the light source can be irradiated in the slit 1 of the shell, and then the light beam of the light source will propagate in the optical path system, thereby realizing light measurement and analysis.

[0067] From the foregoing, the utility model provides an optical path system and stigmatic echelle spectrometer, and the following will give Example 1 and Comparative Example 1 to illustrate the stigmatic effect of the utility model.

[0068] Example 1

[0069] Please refer to Figure 1 The Example 1 of the utility model is the optical element and optical path structure of the above embodiment, that is, comprising slit 1, collimator 2, prism 30 and echelle grating 31, aspheric mirror 4 and detector 5, and the whole optical element is cross type optical path.

[0070] Comparative Example 1

[0071] Please refer to Figure 2 The Comparative Example 1 of the utility model and Example 1, the difference lies in that, in Comparative Example 1, it is not aspheric mirror 4, but spherical mirror; and in Comparative Example 1, the whole optical element is not cross type optical path, but M type optical path structure.

[0072] The optical analysis of Example 1 and Comparative Example 1 is carried out, and the results are shown in Figure 3 and Figure 4 .

[0073] Figure 3 The optical point diagram result of Example 1 is shown in the result figure, and the result figure legend corresponds to the wavelength, the RMS radius (root mean square radius) in Example 1 is 40.038 um, and the GEO radius (geometric radius) is 67.471, that is, the point diagram of the whole Example 1 corresponds to 40 um.

[0074] Figure 4 The optical point diagram result of Comparative Example 1 is shown in the result figure, and the result figure legend corresponds to the wavelength, the RMS radius (root mean square radius) in Comparative Example 1 is 72.119 um, and the GEO radius (geometric radius) is 126.546, and the point diagram of the whole Comparative Example 1 corresponds to 72 um.

[0075] Therefore, the optical path system proposed in Example 1 realizes the 40 um level of stigmation effect, and the system resolution is improved well.

[0076] The above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that the technical solutions recorded in the foregoing examples can be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

[0077] Finally, it should be noted that in this paper, relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations.

Claims

1. An optical path system, characterized by, The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system.

2. The optical path system according to claim 1, characterized in that The application relates to an optical path system.

3. The optical path system according to claim 1, characterized by The application relates to an optical path system.

4. The optical path system according to claim 1, characterized by The application relates to an optical path system.

5. The optical path system according to claim 1 or 4, characterized in that, The application relates to an optical path system.

6. The optical path system according to claim 1, characterized by The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system.

7. The optical path system according to claim 6, characterized in that The application relates to an optical path system.

8. The optical path system according to claim 6, characterized in that The application relates to an optical path system.

9. The optical path system according to claim 6, characterized in that The application relates to an optical path system.

10. An aplanatic echelle spectrometer, characterized by, The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path system. The application relates to an optical path

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