Medium-echelle grating spectrometer structure

Abstract

The utility model relates to the technical field of spectrometers, and discloses an echelle grating spectrometer structure which comprises a box body, an optical fiber adapter, an aberration correction mirror group, a collimating mirror, an echelle grating, a reflective prism, a focusing mirror, a DMD, a PMT focusing mirror and a PMT detector, a box bottom plate is fixed at the bottom of the box body, the optical fiber adapter is fixed on a front plate of the box body, and the optical fiber adapter is fixed on a rear plate of the box body. An incidence small hole is formed in the center of the optical fiber adapter, the aberration correction lens set is fixed to the inner wall of a front plate of the box body and located at the rear end of the optical fiber adapter, a mounting table is fixed to the upper end of the right portion of the box bottom plate, the collimating mirror and the reflective prism are arranged at the upper end of the rear portion of the mounting table, and the echelle grating is arranged at the upper end of the front portion of the mounting table. And the focusing mirror and the PMT focusing mirror are respectively fixed in front of the left part of the box bottom plate. According to the utility model, the manufacturing cost of the echelle grating spectrometer can be greatly reduced, and the echelle grating spectrometer also has better imaging quality.

Description

Technical Field

[0001] The utility model relates to the technical field of spectrometers, in particular to a structure of an echelle grating spectrometer. Background Art

[0002] An echelle grating spectrometer is a spectrometer with extremely high spectral resolution. By utilizing the characteristics of the echelle grating, which is the core dispersion element, such as a large blaze angle, low groove density, and operating at a high diffraction order, it has an extremely high angular dispersion rate. In the prior art, echelle grating spectrometers usually adopt area array detectors (CCD) or image-intensified area array detectors (ICCD), which require high detection sensitivity, resulting in a complex structure and relatively high cost for the detectors supporting the instrument. The high development cost also makes the echelle grating spectrometer, despite its extremely high spectral resolution, only applicable to specific application fields and not "affordable for the general public", thus restricting its use.

[0003] Spatial light modulators (DMD) mainly adopt liquid crystal technology and achieve the modulation of the amplitude and phase of the light wavefront by utilizing the changes of materials under different electro-control parameter conditions and their different effects on incident light; photomultiplier tube detectors (PMT) can convert weak optical signals into electrical signals, and both of them are relatively inexpensive. With the development of their technologies, they have been applied at present. Summary of the Utility Model

[0004] In order to overcome the deficiencies of the prior art, the purpose of the present utility model is to provide a structure of an echelle grating spectrometer different from the existing structure, which can significantly reduce the manufacturing cost of the echelle grating spectrometer and also has good imaging quality.

[0005] The utility model is realized by the following technical solutions: A structure of an echelle grating spectrometer, which includes a box body, an optical fiber adapter, an aberration correction lens group, a collimating mirror, an echelle grating, a reflecting prism, a focusing mirror, a DMD, a PMT focusing mirror and a PMT detector. A box bottom plate is fixed at the bottom of the box body. The optical fiber adapter is fixed on the front plate of the box body, and an incident small hole is formed in the center of the optical fiber adapter. The aberration correction lens group is fixed on the inner wall of the front plate of the box body, and the aberration correction lens group is located at the rear end of the optical fiber adapter. An installation platform is fixed at the upper right part of the box bottom plate. The collimating mirror and the reflecting prism are arranged at the upper rear part of the installation platform. The echelle grating is arranged at the upper front part of the installation platform. The focusing mirror and the PMT focusing mirror are respectively fixed at the front left part of the box bottom plate. The DMD and the PMT detector are respectively fixed at the rear left part of the box bottom plate. Light enters from the incident small hole in the center of the optical fiber adapter, passes through the aberration correction lens group and the collimating mirror, and then is incident on the echelle grating in parallel. The light is dispersed by the echelle grating, and then is incident on the reflecting prism in a parallel manner. The reflecting prism disperses the incident light again, and the dispersion direction is perpendicular to the dispersion direction of the echelle grating and does not interfere with each other. The reflected light passes through the focusing mirror, and the light in the working band is converged onto the DMD. After being reflected by the DMD and the PMT focusing mirror, all the wavelength information is transmitted to the PMT detector.

[0006] Further, the collimating mirror is installed through a collimating mirror seat, the echelle grating is installed through a grating base, the reflecting prism is installed through a prism platform, the focusing mirror is installed through a focusing mirror adjustment seat, the DMD is installed through a DMD adjustment structure, the PMT focusing mirror is installed through a PMT focusing mirror adjustment structure, and the PMT detector is installed through a PMT detector seat.

[0007] Further, the focusing mirror adjustment seat includes a focusing mirror mounting frame, a mirror fixing plate, a threaded column seat, an extension rod, an adjustment knob, a connecting plate and a slide structure. The bottom end of the threaded column seat is fixed at the top end of the connecting plate. The bottom end of the connecting plate is fixed at the driving end of the slide structure. The threaded column seat is located at the rear side of the mirror fixing plate. The front part of the extension rod is installed in the threaded column seat through thread fit. The focusing mirror mounting frame is fixed at the front end of the mirror fixing plate. The adjustment knob is fixed at the rear end of the extension rod. The front end of the extension rod contacts the rear end of the mirror fixing plate. A plurality of springs are arranged between the threaded column seat and the mirror fixing plate. The rear end of the spring is connected to the threaded column seat. Four mounting holes are arranged on the mirror fixing plate, and a hook is arranged in each mounting hole. Among them, the hooks in the two lower mounting holes are arranged horizontally, and the hooks in the two side mounting holes are arranged vertically. The front end of the spring is connected to the hook.

[0008] Further, the DMD adjustment structure includes a DMD mounting bracket and a slide table structure. The DMD is fixed on the DMD mounting bracket, and the DMD mounting bracket is fixed to the driving end of the slide table structure.

[0009] Further, the slide table structure includes a carrier table, a slide table bottom plate, slide table support blocks, slide rods, a lead screw knob, and a lead screw. The two slide table support blocks are symmetrically fixed on both sides of the upper end of the slide table bottom plate. The slide rods and the lead screw are both arranged between the inner sides of the two slide table support blocks. The slide rods are located on both sides of the lead screw. One end of the lead screw extends outside the slide table support block and is fixedly connected to the lead screw knob. The carrier table is sleeved on the slide rods and the lead screw, and the carrier table is driven to move horizontally by rotating the lead screw.

[0010] Further, the lead screw knob and the adjustment knob both extend outside the box body so that they can be adjusted outside the box body.

[0011] Further, a box cover is fixed to the top of the box body by screws.

[0012] Further, a through groove is provided at the rear side of the box body.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0014] 1. For the echelle grating spectrometer structure of the present utility model, the combination of DMD + PMT is used to replace the two-dimensional CCD or ICCD used in the traditional echelle grating spectrometer, which can greatly reduce the manufacturing cost of the echelle grating spectrometer.

[0015] 2. For the echelle grating spectrometer structure of the present utility model, by rotating the two adjustment knobs, the tilting angles of the focusing mirror in the horizontal and vertical directions can be adjusted; through the slide table structure, the distance between the focusing mirror and the DMD before and after can be adjusted, and the distances between the DMD and the focusing mirror and the PMT focusing mirror left and right can be adjusted, so as to adjust the light spot and make it better focus on the image plane of the DMD, having better imaging quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic structural diagram of the echelle grating spectrometer structure of the present utility model after removing the box cover;

[0017] Figure 2 is a schematic structural diagram of the focusing mirror and the focusing mirror adjustment seat in the present utility model Figure 1 ;

[0018] Figure 3It is a schematic structure diagram of the focusing mirror and the focusing mirror adjustment seat in the present utility model Figure 2 ;

[0019] Figure 4 It is a schematic structure diagram of DMD7 and the DMD adjustment structure 71 in the present utility model;

[0020] Figure 5 It is a schematic structure diagram of the focusing mirror mounting bracket and the mirror fixing plate in the present utility model Figure 1 ;

[0021] Figure 6 It is a schematic structure diagram of the focusing mirror mounting bracket and the mirror fixing plate in the present utility model Figure 2 ;

[0022] Figure 7 It is the optical path diagram of the present utility model.

[0023] In the figure: collimating mirror - 3; echelle grating - 4; reflecting prism - 5; focusing mirror - 6; DMD - 7; PMT focusing mirror - 8; PMT detector - 9; box body - 11; box bottom plate - 12; mounting table - 13; through groove - 14; fiber optic adapter seat - 21; aberration correction lens group - 22; collimating mirror seat - 31; grating base - 41; prism platform - 51; focusing mirror adjustment seat - 61; slide table structure - 70; DMD adjustment structure - 71; PMT focusing mirror adjustment structure - 81; PMT detector seat - 91; focusing mirror mounting bracket - 611; mirror fixing plate - 612; threaded stud seat - 613; extension rod - 614; adjustment knob - 615; connecting plate - 616; spring - 617; mounting hole - 618; hook - 619; DMD mounting bracket - 711; bearing table - 712; slide table bottom plate - 713; slide table support block - 714; slide rod - 715; lead screw knob - 716; lead screw - 717. Specific embodiments

[0024] The following uses specific specific examples to illustrate the implementation manners of the present utility model. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can also be implemented or applied through other different specific implementation manners. The details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present utility model. It should be noted that, without conflict, the following embodiments and the features in the embodiments can be combined with each other.

[0025] The purpose of the present utility model is to provide an echelle grating spectrometer structure in view of the defects of the prior art.

[0026] Embodiment 1

[0027] This embodiment provides a structure of an echelle grating spectrometer. Referring to Figure 1 , Figure 7 as shown, it includes a box body 11, an optical fiber adapter seat 21, an aberration correction lens group 22, a collimating mirror 3, an echelle grating 4, a reflecting prism 5, a focusing mirror 6, a DMD 7, a PMT focusing mirror 8, and a PMT detector 9. A box bottom plate 12 is fixed to the bottom of the box body 11, and a box cover (not shown in the figure) is fixed to its top by screws. A through slot 14 is provided at the rear side of the box body 11.

[0028] The optical fiber adapter seat 21 is fixed on the front plate of the box body 11. An incident small hole is formed in the center of the optical fiber adapter seat 21. The aberration correction lens group 22 is fixed on the inner wall of the front plate of the box body 11, and the aberration correction lens group 22 is located at the rear end of the optical fiber adapter seat 21. An installation platform 13 is fixed to the upper right part of the box bottom plate 12. The collimating mirror 3 and the reflecting prism 5 are arranged at the upper rear part of the installation platform 13, and the echelle grating 4 is arranged at the upper front part of the installation platform 13. The axes of the optical fiber adapter seat 21, the aberration correction lens group 22, and the collimating mirror 3 are on the same straight line. Specifically, the collimating mirror 3, the echelle grating 4, and the reflecting prism 5 are respectively installed and fixed on the upper end of the installation platform 13 through a collimating mirror base 31, a grating base 41, and a prism platform 51. The focusing mirror 6 and the PMT focusing mirror 8 are respectively installed and fixed on the front left part of the box bottom plate 12 through a focusing mirror adjustment seat 61 and a PMT focusing mirror adjustment structure 81. The DMD 7 and the PMT detector 9 are respectively fixed on the rear left part of the box bottom plate 12 through a DMD adjustment structure 71 and a PMT detector seat 91.

[0029] When the structure of the echelle grating spectrometer of the present utility model works, light enters from the incident small hole 1 in the center of the optical fiber adapter seat 21. After passing through the aberration correction lens group 22 and the collimating mirror 3, it is incident on the echelle grating 4 in parallel. The echelle grating 4 works in a quasi-Littrow mode. The light is dispersed by the echelle grating 4 and then incident on the reflecting prism 5 in a parallel manner. The reflecting prism 5 disperses the incident light again, and its dispersion direction is perpendicular to the dispersion direction of the echelle grating 4 and does not interfere with each other. The reflected light passes through the focusing mirror 6, and the light in the working band is converged onto the DMD 7. After being reflected by the DMD 7 and passing through the PMT focusing mirror 8, finally all the wavelength information is transmitted to the PMT detector 9. After relevant data processing, a unique two-dimensional spectrum of the echelle grating spectrometer will be obtained eventually. The structure of the echelle grating spectrometer of the present utility model uses a combination of DMD + PMT, replacing the two-dimensional CCD or ICCD used in traditional echelle grating spectrometers, and can greatly reduce the manufacturing cost of the echelle grating spectrometer.

[0030] Embodiment II

[0031] This embodiment provides a structure of an echelle grating spectrometer. Refer to Figures 2 - 6 As shown, the focusing mirror adjusting seat 61 includes a focusing mirror mounting frame 611, a mirror fixing plate 612, a threaded post seat 613, an extension rod 614, an adjusting knob 615, a connecting plate 616, and a slide table structure 70. The bottom end of the threaded post seat 613 is fixed to the top end of the connecting plate 616, and the bottom end of the connecting plate 616 is fixed to the driving end of the slide table structure 70. The threaded post seat 613 is located at the rear side of the mirror fixing plate 612. The front part of the extension rod 614 is installed in the threaded post seat 613 by thread fit. The focusing mirror mounting frame 611 is fixed to the front end of the mirror fixing plate 612. The adjusting knob 615 is fixed to the rear end of the extension rod 614. The front end of the extension rod 614 contacts the rear end of the mirror fixing plate 612. A plurality of springs 617 are arranged between the threaded post seat 613 and the mirror fixing plate 612. The rear end of the spring 617 is connected to the threaded post seat 613. Four mounting holes 618 are provided on the mirror fixing plate 612, and a hook 619 is arranged in each mounting hole 618. The hooks 619 in the two mounting holes 618 located below are horizontally arranged, and the hooks 619 in the two mounting holes 618 located on the sides are vertically arranged. The front end of the spring 617 is connected to the hook 619. The adjusting knob 615 extends to the outside of the box body 11 so that it can be adjusted outside the box body 11. The focusing mirror adjusting seat 61 in this embodiment can use an optical adjustment frame of the THORLABS brand in the prior art. When the extension rod 614 located below is rotated forward, its front end will push the lower part of the rear end of the mirror fixing plate 612, so that the mirror fixing plate 612 rotates in the vertical direction. When the extension rod 614 located on the side is rotated forward, its front end will push the side end of the mirror fixing plate 612, so that the mirror fixing plate 612 rotates in the horizontal direction. By rotating the two adjusting knobs 615, the tilting angles of the focusing mirror 6 in the horizontal and vertical directions can be adjusted. Through a slide table structure 70 in the focusing mirror adjusting seat 61, the front and rear movement of the focusing mirror 6 can be accurately adjusted, and the distance between the focusing mirror 6 and the imaging surface of the DMD 7 can be changed, so as to correct the imaging quality of the entire echelle grating spectrometer.

[0032] Refer to Figure 4 As shown, the DMD adjusting structure 71 includes a DMD mounting frame 711 and a slide table structure 70. The DMD 7 is fixed to the DMD mounting frame 711, and the DMD mounting frame 711 is fixed to the driving end of the slide table structure 70.

[0033] Refer to Figure 4As shown in the figure, the slide table structure 70 includes a carrier table 712, a slide table bottom plate 713, slide table support blocks 714, slide rods 715, a lead screw knob 716, and a lead screw 717. The two slide table support blocks 714 are symmetrically fixed on both sides of the upper end of the slide table bottom plate 713. The slide rods 715 and the lead screw 717 are both arranged between the inner sides of the two slide table support blocks 714. The slide rods 715 are located on both sides of the lead screw 717. One end of the lead screw 717 extends outside the slide table support block 714 and is fixedly connected to the lead screw knob 716. The lead screw knob 716 extends outside the box body 11, so that it can be adjusted outside the box body 11. The carrier table 712 is sleeved on the slide rods 715 and the lead screw 717, and the carrier table 712 is driven to move horizontally by rotating the lead screw 717. Through the slide table structure 70 in the DMD adjustment structure 71, the left and right movement of the DMD 7 can be adjusted, so as to adjust the left and right distances between the DMD 7 and the focusing mirror 6 and the PMT focusing mirror 8. By cooperating with the adjustment of the focusing mirror 6, all the light spots are focused on the image plane of the DMD 7.

[0034] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A structure of an echelle grating spectrometer, characterized in that: It includes a box body (11), an optical fiber adapter base (21), an aberration correction lens group (22), a collimating mirror (3), an echelle grating (4), a reflecting prism (5), a focusing mirror (6), a DMD (7), a PMT focusing mirror (8) and a PMT detector (9). A box bottom plate (12) is fixed to the bottom of the box body (11). The optical fiber adapter base (21) is fixed on the front plate of the box body (11), and an incident small hole is formed in the center of the optical fiber adapter base (21). The aberration correction lens group (22) is fixed on the inner wall of the front plate of the box body (11), and the aberration correction lens group (22) is located at the rear end of the optical fiber adapter base (21). An installation platform (13) is fixed to the upper right end of the box bottom plate (12). The collimating mirror (3) and the reflecting prism (5) are arranged at the upper rear part of the installation platform (13). The echelle grating (4) is arranged at the upper front part of the installation platform (13). The focusing mirror (6) and the PMT focusing mirror (8) are respectively fixed in front of the left part of the box bottom plate (12). The DMD (7) and the PMT detector (9) are respectively fixed behind the left part of the box bottom plate (12). Light enters through the incident small hole (1) in the center of the optical fiber adapter base (21), passes through the aberration correction lens group (22) and the collimating mirror (3), and then is incident on the echelle grating (4) in parallel. The light is dispersed by the echelle grating (4), and then is incident on the reflecting prism (5) in a parallel manner. The reflecting prism (5) disperses the incident light again, and the dispersion direction is perpendicular to the dispersion direction of the echelle grating (4) and does not interfere with each other. The reflected light passes through the focusing mirror (6), and the light in the working band is converged on the DMD (7). After being reflected by the DMD (7) and the PMT focusing mirror (8), all the wavelength information is transmitted to the PMT detector (9).

2. The structure of the echelle grating spectrometer according to claim 1, wherein: The collimating mirror (3) is installed through a collimating mirror base (31). The echelle grating (4) is installed through a grating base (41). The reflecting prism (5) is installed through a prism platform (51). The focusing mirror (6) is installed through a focusing mirror adjustment seat (61). The DMD (7) is installed through a DMD adjustment structure (71). The PMT focusing mirror (8) is installed through a PMT focusing mirror adjustment structure (81). The PMT detector (9) is installed through a PMT detector base (91).

3. The structure of the echelle grating spectrometer as described in claim 2, wherein: The described focusing mirror adjusting base (61) includes a focusing mirror mounting bracket (611), a mirror fixing plate (612), a threaded stud base (613), an extension rod (614), an adjusting knob (615), a connecting plate (616) and a slide structure (70). The threaded stud base (613) is fixed to the top end of the connecting plate (616). The bottom end of the connecting plate (616) is fixed to the driving end of the slide structure (70). The threaded stud base (613) is located at the rear side of the mirror fixing plate (612). The front part of the extension rod (614) is installed in the threaded stud base (613) by screw fit. The focusing mirror mounting bracket (611) is fixed to the front end of the mirror fixing plate (612). The adjusting knob (615) is fixed to the rear end of the extension rod (614). The front end of the extension rod (614) contacts the rear end of the mirror fixing plate (612). A plurality of springs (617) are arranged between the threaded stud base (613) and the mirror fixing plate (612). The rear end of the spring (617) is connected to the threaded stud base (613). A plurality of mounting holes (618) are provided on the mirror fixing plate (612). A hook (619) is arranged in each mounting hole (618). The front end of the spring (617) is connected to the hook (619).

4. The structure of the echelle grating spectrometer according to claim 3, wherein: The described DMD adjusting structure (71) includes a DMD mounting bracket (711) and a slide structure (70). The DMD (7) is fixed to the DMD mounting bracket (711). The DMD mounting bracket (711) is fixed to the driving end of the slide structure (70).

5. The echelle grating spectrometer structure according to claim 3 or 4, characterized in that: The described slide structure (70) includes a carrier (712), a slide base plate (713), slide support blocks (714), slide rods (715), a lead screw knob (716) and a lead screw (717). Two slide support blocks (714) are symmetrically fixed to both sides of the upper end of the slide base plate (713). The slide rods (715) and the lead screw (717) are both arranged between the inner sides of the two slide support blocks (714). The slide rods (715) are located on both sides of the lead screw (717). One end of the lead screw (717) extends out of the slide support block (714) and is connected and fixed to the lead screw knob (716). The carrier (712) is sleeved on the slide rods (715) and the lead screw (717). The carrier (712) is driven to move horizontally by rotating the lead screw (717).

6. The echelle grating spectrometer structure according to claim 5, wherein: The lead screw knob (716) and the adjusting knob (615) both extend out of the outer side of the box body (11), so that they can be adjusted outside the box body (11).

7. The structure of the echelle grating spectrometer according to claim 6, characterized in that: A box cover is fixed to the top of the box body (11) by screws.

8. The structure of the echelle grating spectrometer according to claim 6, characterized in that: A through groove (14) is provided at the rear side of the box body (11).

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