CN111442842A - High-resolution and high-sensitivity Raman spectrometer - Google Patents

Abstract

The invention relates to a high-resolution high-sensitivity Raman spectrometer, and belongs to the field of spectrometers. The invention provides a method for reducing the vertical height of a light spot at a focus by adopting two or more cylindrical lenses with a certain inclination angle and placing the two or more cylindrical lenses in front of a light-sensitive surface of a detector; a wide-spectrum high-sensitivity Raman spectrometer is provided, a concave reflecting mirror is adopted to replace a traditional lens to serve as a Raman light collecting element, a Raman light excitation and collection device is separated, a dichroic mirror is omitted, and the low wave number part of a Raman spectrum is expanded to be below 100cm < -1 >; the relationship between the focal length and the deflection angle of the two concave mirrors when the aberration is minimum is determined.

Description

A high-resolution and high-sensitivity Raman spectrometer

technical field

The invention relates to a Raman spectrometer, in particular to a high-resolution and high-sensitivity Raman spectrometer.

Background technique

Raman spectroscopy is a kind of scattering spectroscopy. Raman spectroscopic analysis is based on the Raman scattering effect discovered by Indian scientist C.V. Raman (Raman), and analyzes the scattering spectrum different from the incident light wavelength to obtain information on molecular vibration and rotation, and is applied to the study of molecular structure. an analytical method. With the development of laser technology, Raman spectroscopy is increasingly used to detect various substances. Since different molecules have specific vibration and rotation energy levels, when a certain wavelength of laser light scatters with a material molecule, a part of the laser photons exchange energy with the material molecule. After the energy exchange occurs, the laser photon wavelength changes. Since different vibrational and rotational energy levels correspond one-to-one with the change of laser photon wavelength, the vibrational or rotational energy level difference of the molecule can be determined by analyzing the laser spectrum after scattering, and according to these energy level differences, it is possible to analyze what kind of substance the scattering molecule is. . Just as a fingerprint can be used to determine the owner of a fingerprint, Raman spectroscopy can be used to determine the type of molecule. At the same time, the concentration of the molecule can be determined by the intensity of the Raman spectrum. In recent years, with the maturity of optical devices such as lasers, detectors, and filters, Raman spectrometers have developed rapidly at home and abroad.

Existing Raman spectrometers generally use a dichroic mirror tilted at 45° to reflect laser light and transmit Raman light. Since dichroic mirrors generally cannot transmit low-wavenumber Raman light in the 0-200cm-1 band, such Raman spectrometers with dichroic mirrors cannot detect substances with characteristic peaks in the 0-200cm-1 band. Especially for Raman spectrometers with laser light sources in the ultraviolet band, such as 266nm ultraviolet Raman spectrometers, dichroic mirrors are not only expensive, but also produce fluorescence. In addition, for ultraviolet band laser, double cemented achromatic lens cannot be used, and single lens and aspheric lens have large chromatic aberration, which makes Raman spectrometer very low sensitivity. Moreover, some detectors with small detection heights cannot fully receive Raman light, resulting in low sensitivity of Raman spectrometers. These existing technical bottlenecks limit the wide application of Raman spectrometers.

SUMMARY OF THE INVENTION

The present invention is aimed at that the existing Raman spectrometer is difficult to detect the low wave number Raman light in the 0-200cm-1 band, the ultraviolet Raman spectrometer has low sensitivity due to the large chromatic aberration of the lens, and some detectors with small detection height cannot fully receive To Raman light and other issues, a wide-spectrum high-sensitivity Raman spectrometer is proposed. Using concave mirrors instead of lenses as Raman light collection elements, the relationship between the focal length and the tilt angle of two concave mirrors when the aberration is minimized is proposed. And two cylindrical lenses with a certain inclination angle are placed in front of the photosensitive surface of the detector to further improve the sensitivity and resolution of the Raman spectrometer. Therefore, the low wavenumber part of the Raman spectral range is extended to below 100 cm-1, and the sensitivity and resolution of the Raman spectrometer can be significantly improved.

The technical scheme of the present invention is: a high-resolution and high-sensitivity Raman spectrometer.

The device of the present invention comprises: a slit, a first concave mirror, an optical filter, a grating, a second concave mirror, a first cylindrical lens, a second cylindrical lens, and a detector. The Raman light transmitted through the slit is collimated after being reflected by the first concave mirror, and then the laser light is filtered out by one or more filters. The grating diffracts different wavelengths of Raman light to different angles in the horizontal direction, and is then reflected by the second concave mirror and focused on the photosensitive surface of the detector. The first cylindrical lens and the second cylindrical lens are located between the second concave mirror and the photosensitive surface of the detector. The detectors can be CCD, CMOS or other photosensitive elements. The first cylindrical lens and the second cylindrical lens are respectively deflected by a small angle relative to the photosensitive surface of the detector, generally 0-20°. The first cylindrical lens and the second cylindrical lens can be a cylindrical concave lens and a cylindrical convex lens respectively, can be two cylindrical convex lenses, or can be replaced by one or more cylindrical lenses, and each cylindrical lens can be a convex lens or a convex lens. They are concave lenses, which are respectively deflected by a certain angle relative to the photosensitive surface of the detector.

For the part before the slit, there are four embodiments of the present invention.

其中，f1、f2分别为第一带孔凹面反射镜、第二带孔凹面反射镜焦距，θ1为第一带孔凹面反射镜中心点法线与中心点和探测点连线夹角、θ2为第二带孔凹面反射镜中心点法线和狭缝中心点连线夹角。同时，第一带孔凹面反射镜中心与探测点距离：x1＝f1*cos(θ1)，第二带孔凹面反射镜中心距离入射狭缝x2＝f2*cos(θ2)。In the first embodiment, the device includes: a laser, a laser focusing lens, a first small hole, a first concave mirror with a hole, a second concave mirror with a hole, a second small hole, and a detection point. The laser emitted from the laser passes through the laser focusing lens and passes through the first small hole of the concave mirror with a hole and the second small hole of the second concave mirror with a hole, and then focuses on the detection point, and the sample is placed at the detection point for Raman light detection. . The Raman light generated at the detection point passes through the second small hole, is reflected and collimated by the first concave mirror with holes, and is then reflected and focused on the slit by the second concave mirror with holes. The focal length and deflection angle of the first concave mirror with holes and the second concave mirror with holes must satisfy the following relationship:

Among them, f1 and f2 are the focal lengths of the first concave mirror with holes and the second concave mirror with holes, respectively, θ1 is the angle between the normal line of the center point of the first concave mirror with holes and the connection line between the center point and the detection point, and θ2 is The included angle between the normal line of the center point of the second concave mirror with holes and the line connecting the center point of the slit. At the same time, the distance between the center of the first concave mirror with holes and the detection point is: x1=f1*cos(θ1), and the center of the second concave mirror with holes is from the incident slit x2=f2*cos(θ2).

In the second embodiment, the device includes: a laser, a laser focusing lens, a first small hole, a first concave mirror with a hole, a second concave mirror with a hole, a second small hole, a detection point, a slit, and a flat mirror . The laser emitted from the laser is reflected by the plane mirror after passing through the laser focusing lens, and then focused on the detection point after passing through the second small hole. The Raman light generated by the detection point passes through the second small hole and is reflected by the first concave mirror with a hole. Collimated, and then reflected by the second concave mirror with holes and then focused on the slit through the first small hole. The second embodiment is a special case of θ1=0 and θ2=0 in the first embodiment, the first concave mirror with holes and the second concave mirror with holes are coaxial, and neither is deflected.

其中，f1、f3分别为第一带孔凹面反射镜、第三凹面反射镜焦距，θ1为第一带孔凹面反射镜中心点法线与中心点和探测点连线夹角、θ3为第三凹面反射镜中心点法线与中心点和狭缝中心点连线夹角。同时，第一带孔凹面反射镜中心与探测点距离：x1＝f1*cos(θ1)，第三凹面反射镜中心距离入射狭缝x3＝f3*cos(θ3)。滤光片位于第一凹面反射镜与光栅之间，或位于第一带孔凹面反射镜与第三凹面反射镜之间。第一柱透镜、第二柱透镜位于二凹面反射镜与探测器之间，或位于第三凹面反射镜与狭缝之间。In the third embodiment, the device includes: a laser, a laser focusing lens, a first small hole, a first concave mirror with a hole, a third concave mirror, and a detection point. The laser emitted by the laser is focused on the detection point by a laser focusing lens, and the Raman light generated by the detection point is reflected by the first concave mirror with holes and then collimated, and then focused on the slit by the third concave mirror. The focal length and deflection angle of the first concave mirror with holes and the third concave mirror must satisfy the following relationship:

Among them, f1 and f3 are the focal lengths of the first concave mirror with holes and the third concave mirror, respectively, θ1 is the angle between the normal line of the center point of the first concave mirror with holes and the connection line between the center point and the detection point, and θ3 is the third The angle between the normal line of the center point of the concave mirror and the line connecting the center point and the center point of the slit. At the same time, the distance between the center of the first concave mirror with holes and the detection point is: x1=f1*cos(θ1), and the center of the third concave mirror is from the incident slit x3=f3*cos(θ3). The filter is located between the first concave mirror and the grating, or between the first apertured concave mirror and the third concave mirror. The first cylindrical lens and the second cylindrical lens are located between the two concave mirrors and the detector, or between the third concave mirror and the slit.

其中，f4、f3分别为第四凹面反射镜、第三凹面反射镜焦距，θ4为第四凹面反射镜中心点法线与中心点和探测点连线夹角、θ3为第三凹面反射镜中心点法线与中心点和狭缝中心点连线夹角。同时，第四凹面反射镜中心与探测点距离：x4＝f4*cos(θ4)，第三凹面反射镜中心距离入射狭缝x3＝f3*cos(θ3)。滤光片位于第一凹面反射镜9与光栅11之间，或位于第四凹面反射镜与第三凹面反射镜之间。In the fourth embodiment, the device includes: a laser, a laser focusing lens, a detection point, a fourth concave mirror, and a third concave mirror. The laser emitted by the laser is focused on the detection point by the laser focusing lens, and the Raman light generated by the detection point is reflected by the fourth concave mirror and then collimated, and then focused on the slit by the third concave mirror. The focal length and deflection angle of the fourth concave mirror and the third concave mirror must satisfy the following relationship:

Among them, f4 and f3 are the focal lengths of the fourth concave mirror and the third concave mirror, respectively, θ4 is the angle between the normal line of the center point of the fourth concave mirror and the connection line between the center point and the detection point, and θ3 is the center of the third concave mirror The angle between the point normal and the line connecting the center point and the center point of the slit. At the same time, the distance between the center of the fourth concave mirror and the detection point: x4=f4*cos(θ4), and the distance from the center of the third concave mirror to the incident slit x3=f3*cos(θ3). The filter is located between the first concave mirror 9 and the grating 11, or between the fourth concave mirror and the third concave mirror.

The beneficial effects of the present invention are:

1. A high-resolution and high-sensitivity Raman spectrometer is proposed, which uses a concave mirror instead of a traditional lens as a Raman light collection element, separates the Raman light excitation and collection device, and eliminates the dichroic mirror. The low wavenumber part of the Mann spectrum extends below 100cm-1.

2. The relationship between the focal length and deflection angle of the two concave mirrors is proposed when the aberration is the smallest, which improves the sensitivity and resolution of the Raman spectrometer.

3. It is proposed to use two cylindrical lenses with a certain inclination angle, which are placed in front of the photosensitive surface of the detector or in front of the slit to improve the sensitivity and resolution of the Raman spectrometer.

Description of drawings

FIG. 1 is a schematic structural diagram of a device according to a first embodiment of the present invention;

2 is a schematic diagram of the device structure of the second embodiment of the present invention;

3 is a schematic structural diagram of a device according to a third embodiment of the present invention;

FIG. 4 is a schematic diagram of a device structure according to a fourth embodiment of the present invention;

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

In the first embodiment of the present invention, the device is shown in Figure 1: a laser 1, a laser focusing lens 2, a first small hole 3, a first concave mirror with holes 4, a second concave mirror with holes 5, a second Small hole 6 , detection point 7 , slit 8 , first concave mirror 9 , filter 10 , grating 11 , second concave mirror 12 , first cylindrical lens 13 , second cylindrical lens 14 , detector 15 . The laser 1 can be of different laser wavelengths, such as 213 nm, 266 nm, 532 nm, 785 nm, 1064 nm, and the like. The laser 1 can be either a continuous laser or a pulsed laser, but generally the laser line width is required to be less than or equal to 0.2 nm. If the laser output from the laser 1 also contains other wavelength bands, a narrow band needs to be placed between the laser 1 and the laser focusing lens 2. Filters filter out other wavelengths. If the divergence angle of the laser emitted by the laser 1 is relatively large, a group of laser collimating beam expanding lenses need to be inserted into the laser focusing lens 2, generally a concave lens and a convex lens, or two convex lenses. The two lenses form a telescope system for The laser beam is collimated and expanded. The laser focusing lens 2 may be a single lens, a doublet lens or an aspheric lens. For laser light sources in the visible and near-infrared bands (such as 532nm, 785nm, 1064nm), the laser focusing lens 2 is generally a doublet or a single lens; for laser light sources in the ultraviolet band (such as 213nm, 266nm), the laser focusing lens 2 is generally a Aspheric lens or single lens. The first concave mirror 4 with a hole is a concave mirror with a first small hole 3 about 10 mm in diameter in the center. Similarly, the second concave mirror 5 with holes is a concave mirror with a second small hole 6 having a diameter of about 10 mm in the center. The laser focused by the laser focusing lens 2 passes through the first small hole 3 and the second small hole 6 and then focuses on the detection point 7 , and the sample to be tested is located at the detection point 7 . For a solid sample, the detection point 7 needs to be located on the surface of the sample; for a liquid or gas sample, since it is generally housed in a transparent container, the detection point 7 is located inside the liquid or gas sample to be measured in the container. For liquid or gas samples, the laser focusing lens 2 needs to be the same or close to the focal length of the first concave mirror 9 to ensure that the two are confocal, so the laser focusing lens 2 needs to be fixed near the first small hole 3, before or after. A window can be added between the second concave mirror 12 and the detection point, so that the whole machine is sealed. The Raman light generated at the detection point 7 passes through the second small hole 6 , is reflected by the first concave mirror 4 with a hole and then collimated, and then is focused on the slit 8 by the second concave mirror 5 with a hole. After that, the Raman light is reflected by the first concave mirror 9 and then collimated, and then the laser light is filtered out by one or more filters 10, and then the Raman light of different wavelengths is diffracted to different angles in the horizontal direction by the grating 11. Reflected by the second concave mirror 12 and focused on the photosensitive surface of the detector 15 . The first cylindrical lens 13 and the second cylindrical lens 14 are located between the second concave mirror 12 and the photosensitive surface of the detector 15 . The detector 15 may be a CCD, CMOS or other photosensitive elements.

其中，f1、f2分别为第一带孔凹面反射镜4、第二带孔凹面反射镜5焦距，θ1为第一带孔凹面反射镜4中心点法线与中心点和探测点7连线夹角、θ2为第二带孔凹面反射镜5中心点法线和狭缝8中心点连线夹角。同时，第一带孔凹面反射镜4中心与探测点7距离：x1＝f1*cos(θ1)，第二带孔凹面反射镜5中心距离入射狭缝x2＝f2*cos(θ2)。The focal length and deflection angle of the first concave mirror with holes 4 and the second concave mirror with holes 5 must satisfy the following relationship:

Among them, f1 and f2 are the focal lengths of the first concave mirror with holes 4 and the second concave mirror with holes 5 respectively, and θ1 is the connection clip between the normal line of the center point of the first concave mirror with holes 4 and the center point and the detection point 7 The angle, θ2 is the included angle between the normal line of the center point of the second concave mirror 5 with holes and the line connecting the center point of the slit 8 . At the same time, the distance between the center of the first concave mirror 4 with holes and the detection point 7 is: x1=f1*cos(θ1), and the center of the second concave mirror 5 with holes is from the incident slit x2=f2*cos(θ2).

The first cylindrical lens 13 and the second cylindrical lens 14 are inserted between the second concave mirror 12 and the detector 15, in order to compress the light in the vertical direction without substantially changing the transmission of the light in the horizontal direction. Since different detectors 15 have different photosensitive heights in the vertical direction, the necessity of the first cylindrical lens 13 and the second cylindrical lens 14 is particularly evident for the detector 15 with a smaller photosensitive height. Here, the first cylindrical lens 13 and the second cylindrical lens 14 are respectively deflected by a small angle relative to the photosensitive surface of the detector 15, generally 0-10°. The advantage of this is that the aberration in the horizontal direction of the corresponding focal point of each wavelength on the photosensitive surface of the detector 15 can be further eliminated, thereby improving the resolution of the spectrometer. The first cylindrical lens 13 and the second cylindrical lens 14 may be a cylindrical concave lens and a cylindrical convex lens, respectively, may be two cylindrical convex lenses, or may be replaced by one or more cylindrical lenses, and each cylindrical lens may be a convex lens It can also be a concave lens, each of which is deflected by a certain angle relative to the photosensitive surface of the detector 15, but it must be ensured that the entire cylindrical lens group is equivalent to a cylindrical convex lens.

In the second embodiment of the present invention, the device is shown in FIG. 2: a laser 1, a laser focusing lens 2, a first small hole 3, a first concave mirror with holes 4, a second concave mirror with holes 5, a second Small hole 6, detection point 7, slit 8, first concave mirror 9, filter 10, grating 11, second concave mirror 12, first cylindrical lens 13, second cylindrical lens 14, detector 15, Flat mirror 16. The laser light emitted by the laser 1 is reflected by the plane mirror 16 after passing through the laser focusing lens 2, and then focused on the detection point 7 after passing through the second small hole 6. The Raman light generated by the detection point 7 passes through the second small hole 6 and is captured by the first The apertured concave mirror 4 is reflected and collimated, and then reflected by the second apertured concave mirror 5 and then focused on the slit 8 through the first small hole 3. The filter 10 is located on the first concave mirror 9 and the grating 11. In between, the filter 10 can also be placed between the slit 8 and the first concave mirror 9, or between the first apertured concave mirror 4 and the slit 8. The second embodiment is a special case of θ1=0 and θ2=0 in the first embodiment, the first concave mirror with holes and the second concave mirror with holes are coaxial, and neither is deflected. The rest is the same as the first embodiment and will not be repeated.

其中，f1、f3分别为第一带孔凹面反射镜4、第三凹面反射镜16焦距，θ1为第一带孔凹面反射镜4中心点法线与中心点和探测点7连线夹角、θ3为第三凹面反射镜16中心点法线与中心点和狭缝8中心点连线夹角。同时，第一带孔凹面反射镜4中心与探测点7距离：x1＝f1*cos(θ1)，第三凹面反射镜16中心距离入射狭缝x3＝f3*cos(θ3)。滤光片10可以位于第一凹面反射镜9与光栅11之间，也可以位于第一带孔凹面反射镜4与第三凹面反射镜16之间。其余部分与第一种实施方式相同，不再重复。In the third embodiment of the present invention, the device is shown in Figure 3: a laser 1, a laser focusing lens 2, a first small hole 3, a first concave mirror with a hole 4, a third concave mirror 16, a detection point 7, Slit 8 , first concave mirror 9 , filter 10 , grating 11 , second concave mirror 12 , first cylindrical lens 13 , second cylindrical lens 14 , detector 15 . Compared with the first embodiment of the present invention, the third embodiment is different in that the second concave mirror 5 with holes is replaced with a third concave mirror 16 . The laser light emitted by the laser 1 is focused on the detection point 7 by the laser focusing lens 2. The Raman light generated by the detection point 7 is reflected by the first concave mirror 4 with holes and then collimated, and then focused on the slit 8 by the third concave mirror 16. . The focal length and deflection angle of the first concave mirror 4 with holes and the third concave mirror 16 must satisfy the following relationship:

Among them, f1 and f3 are the focal lengths of the first concave mirror 4 with a hole and the third concave mirror 16, respectively, and θ1 is the angle between the normal of the center point of the first concave mirror 4 with a hole and the connection line between the center point and the detection point 7, θ3 is the included angle between the normal line of the center point of the third concave mirror 16 and the line connecting the center point and the center point of the slit 8 . Meanwhile, the distance between the center of the first concave mirror 4 with holes and the detection point 7 is: x1=f1*cos(θ1), and the center of the third concave mirror 16 is from the incident slit x3=f3*cos(θ3). The filter 10 may be located between the first concave mirror 9 and the grating 11 , or may be located between the first concave mirror 4 with holes and the third concave mirror 16 . The rest is the same as the first embodiment and will not be repeated.

其中，f4、f3分别为第四凹面反射镜17、第三凹面反射镜16焦距，θ4为第四凹面反射镜17中心点法线与中心点和探测点7连线夹角、θ3为第三凹面反射镜16中心点法线与中心点和狭缝8中心点连线夹角。同时，第四凹面反射镜17中心与探测点7距离：x4＝f4*cos(θ4)，第三凹面反射镜16中心距离入射狭缝x3＝f3*cos(θ3)。滤光片10可以位于第一凹面反射镜9与光栅11之间，也可以位于第四凹面反射镜17与第三凹面反射镜16之间。其余部分与第一种实施方式相同，不再重复。In the fourth embodiment of the present invention, the device is shown in Figure 4: laser 1, laser focusing lens 2, detection point 7, fourth concave mirror 17, third concave mirror 16, slit 8, first concave reflection Mirror 9 , filter 10 , grating 11 , second concave mirror 12 , first cylindrical lens 13 , second cylindrical lens 14 , detector 15 . The laser light emitted by the laser 1 is focused on the detection point 7 by the laser focusing lens 2 . The Raman light generated by the detection point 7 is reflected by the fourth concave mirror 17 and then collimated, and then focused on the slit 8 by the third concave mirror 16 . The focal length and deflection angle of the fourth concave mirror 17 and the third concave mirror 16 must satisfy the following relationship:

Among them, f4 and f3 are the focal lengths of the fourth concave mirror 17 and the third concave mirror 16, respectively, θ4 is the angle between the normal line of the center point of the fourth concave mirror 17 and the connection line between the center point and the detection point 7, and θ3 is the third The angle between the normal line of the center point of the concave mirror 16 and the line connecting the center point and the center point of the slit 8 is included. At the same time, the distance between the center of the fourth concave mirror 17 and the detection point 7 is: x4=f4*cos(θ4), and the distance from the center of the third concave mirror 16 to the incident slit x3=f3*cos(θ3). The filter 10 may be located between the first concave mirror 9 and the grating 11 , or may be located between the fourth concave mirror 17 and the third concave mirror 16 . The rest is the same as the first embodiment and will not be repeated.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention in any form. Although the present invention has been disclosed above with preferred embodiments, it is not intended to limit the present invention. Personnel, without departing from the scope of the technical solution of the present invention, can make some changes or modifications to equivalent examples of equivalent changes by using the technical content disclosed above, but any content that does not depart from the technical solution of the present invention, according to the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solutions of the present invention.

Claims (10)

1. A high resolution high sensitivity raman spectrometer, the apparatus comprising: the Raman spectrum detector comprises a slit, a first concave reflector, a grating, a second concave reflector, a first cylindrical lens, a second cylindrical lens and a detector, wherein detection light penetrating through the slit is reflected and collimated by the first concave reflector, is diffracted to different angles in the horizontal direction by the grating, and is focused on a photosensitive surface of the detector after being reflected by the second concave reflector, converged by the first cylindrical lens and the second cylindrical lens.

2. A high resolution high sensitivity raman spectrometer according to claim 1, wherein: the first cylindrical lens and the second cylindrical lens are respectively inclined at a certain angle.

3. A high resolution high sensitivity raman spectrometer according to claim 1, wherein: the first and second cylindrical lenses are replaced with one of the following cases: three cylindrical lenses inclined at a certain angle respectively; four cylindrical lenses inclined at a certain angle respectively.

4. A high resolution high sensitivity raman spectrometer according to claim 1, wherein: further comprising: the laser device comprises a laser device, a first small hole, a first holed concave reflector, a second small hole, a detection point and a slit, wherein emergent laser of the laser device passes through the first small hole of the first holed concave reflector and the second small hole of the second holed concave reflector and then focuses on the detection point, a sample is placed at the detection point to be subjected to Raman light detection, Raman light generated at the detection point penetrates through the second small hole and then is reflected and collimated by the first holed concave reflector, and then is reflected and focused on the slit through the second holed concave reflector.

5. The high resolution high sensitivity raman spectrometer of claim 4, wherein: the focal length and the deflection angle of the first concave reflector with holes and the second concave reflector with holes satisfy the following relations:

wherein f1 and f2 are focal lengths of the first holed concave reflector and the second holed concave reflector respectively, theta 1 is an included angle between a normal of a central point of the first holed concave reflector and a connecting line of a central point and a detection point, theta 2 is an included angle between a normal of a central point of the second holed concave reflector and a connecting line of a central point of the slit, and the first holed concave reflector is a concave reflector with a slitThe distance x1 between the center of the concave mirror with holes and the detection point is f1 cos (theta 1), and the distance x2 between the center of the second concave mirror with holes and the incidence slit is f2 cos (theta 2).

6. The broad spectrum high sensitivity raman spectrometer of claim 4, wherein: a plane reflector is added, laser emitted by the laser device is reflected by the plane reflector after passing through the laser focusing lens, passes through the second small hole and is focused on the detection point, Raman light generated by the detection point passes through the second small hole, is reflected by the first perforated concave reflector and is collimated, and then passes through the first small hole after being reflected by the second perforated concave reflector and is focused on the slit.

7. The high resolution high sensitivity raman spectrometer of claim 4, wherein: the second concave reflector with holes is replaced by a third concave reflector, laser emitted by the laser is focused on a detection point, Raman light generated by the detection point is collimated after being reflected by the first concave reflector with holes, and then is focused on the slit through the third concave reflector.

8. A high resolution high sensitivity raman spectrometer according to claim 7, wherein: the focal length and the deflection angle of the first concave reflector with the holes and the third concave reflector meet the following relations:

f1 and f3 are focal lengths of the first holed concave mirror and the third concave mirror respectively, θ 1 is an included angle between a normal of a center point of the first holed concave mirror and a connecting line of the center point and a detection point, θ 3 is an included angle between a normal of a center point of the third concave mirror and a connecting line of the center point and a center point of the slit, a distance x1 between the center of the first holed concave mirror and the detection point is f1 cos (θ 1), and a distance x3 between the center of the third concave mirror and the incident slit is f3 cos (θ 3).

9. A high resolution high sensitivity raman spectrometer according to claim 7, wherein: and further replacing the first holed concave reflector with a fourth concave reflector, focusing laser emitted by the laser on a detection point, reflecting the Raman light generated by the detection point by the fourth concave reflector, collimating the Raman light, and focusing the Raman light on the slit by the third concave reflector.

10. A high resolution high sensitivity raman spectrometer according to claim 9, wherein: the focal length and the deflection angle of the fourth concave reflector and the third concave reflector meet the following relations:

wherein, f4, f3 are fourth concave mirror, third concave mirror focus respectively, and theta 4 is fourth concave mirror central point normal and central point and probing point line contained angle, theta 3 is third concave mirror central point normal and central point and slit central point line contained angle, fourth concave mirror center and probing point distance: x4 is f4 cos (θ 4), and the center of the third concave mirror is away from the entrance slit x3 is f3 cos (θ 3).

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