Spectrometer and aperture for spectrometer

Abstract

A spectrometer, a spectrometer module, and a spectrometer method are provided. The spectrometer module (500) comprises a first screen (3100A) and a second screen (3100B), the first screen including first slits (3102, 3104, 3106, 3108), and the second screen including second slits (3102, 3104, 3106, 3108), and the first screen and the second screen are movable relative to each other to generate a confocal aperture reconstructible from the first and second slits. The first and second slits are elongated in different directions. Also disclosed is a method for acquiring spectral data, comprising the step of providing a confocal aperture penetrating the first and second screens by partially aligning the slits in the first screen with the slit apertures in the second screen. The slits in the first screen and the slits in the second screen are elongated in different directions.

Description

Technical Field

[0001] The present invention relates to a module including a confocal aperture and a spectrometer including a confocal aperture, and in particular to a module including a reconfigurable confocal aperture and a spectrometer including a reconfigurable confocal aperture. Background Art

[0002] Raman spectroscopy is a non-destructive chemical analytical technique frequently used for analyzing chemical or biological samples. The Raman effect is observed when a sample inelastically scatters incident light impinging on the sample. This inelastically scattered light is often referred to as Raman scattered light. Generally, a Raman spectrometer includes a light source for irradiating a sample. Typically, a monochromatic light source such as a laser is used. It is known to use lasers having wavelengths in the visible light region, the near-infrared light region, and the near-ultraviolet light region. Raman scattered light has a different wavelength from that of the light used to irradiate the sample. Raman scattered light can be collected and analyzed.

[0003] Other spectrometric measurement techniques are also known, in which a sample is irradiated with monochromatic light or polychromatic light, and the light is collected and analyzed. Examples thereof include fluorescence spectroscopy and infrared spectroscopy. The present invention is also applicable to such techniques.

[0004] In order to collect only scattered light from a specific plane within a sample, such techniques can be used in a confocal manner. This requires passing the scattered light through a spatial filter that provides a pinhole effect. The spatial filter may be a pinhole, or may be a slit that provides a pinhole effect in one dimension.

[0005] WO92 / 22793A1 discloses a Raman spectrometer having a screen, in which a slit having a pinhole effect extends.

[0006] US2005 / 0128476A1 discloses arrays of different apertures, each of which comprises a set of pinholes and a slit, each of which can function as a confocal aperture. [Overview of the project]

[0007] According to a first embodiment, a spectrometer (optionally a Raman spectrometer) is provided, comprising a first screen and a second screen. The first screen includes a first slit, and the second screen includes a second slit. The first and second screens are movable relative to each other to produce a reconfigurable confocal aperture from the first and second slits (e.g., by partial superposition of the first and second slits). The first and second slits are elongated in different directions. Optionally, the first screen is movable independently of the second screen. Optionally, the first screen is movable relative to other components in the spectrometer. Optionally, the second screen is movable relative to other components in the spectrometer. Optionally, the second screen is movable independently of the first screen. Optionally, the first and second screens are arranged to produce a reconfigurable confocal aperture at the inlet of the spectrograph of the spectrometer. Optionally, the first and second slits are elongated in mutually orthogonal directions. The first screen may contain a plurality of first slits. The second screen may contain a plurality of second slits. Optionally, the plurality of first slits have common dimensions in the first direction and optionally in the longitudinal direction of the slit group. Optionally, each of the plurality of first slits has a different width (i.e., a different dimension in a direction other than the longitudinal direction of the slit group, e.g., a direction perpendicular to the longitudinal direction of the slit group). Each of the plurality of first slits may have a major axis parallel to the major axis of each of the other slits in the plurality of first slits. The plurality of second slits may have common dimensions in the first direction and optionally in the longitudinal direction of the slit group. Each of the plurality of second slits may have a different width (i.e., a different dimension in a direction other than the longitudinal direction of the slit group, e.g., a direction perpendicular to the longitudinal direction of the slit group).Each of the multiple second slits may have a major axis parallel to the major axis of each other in the multiple second slits. Optionally, the major axis of the first slit (or the axis of the multiple first slits) extends in a different direction (e.g., perpendicular) than the major axis of the second slit (or the axis of the multiple second slits). Optionally, the first and second screens are arranged in parallel planes. Optionally, the planes of the first and second screens are perpendicular to the optical axis of the spectrometer. Optionally, the planes of the first and second screens are perpendicular to the optical axis of the objective lens. Optionally, the planes of the first and second screens are perpendicular to the optical axes of the first and second lenses. Optionally, the first and / or second lenses are for focusing light received from a (specific) plane of the sample to a narrow focus at the confocal aperture.

[0008] As described above, by providing a first screen and a second screen, the first and second screens can be moved relative to each other to overlap the first and second slits and create a confocal aperture through which light can pass. The confocal aperture, which penetrates the first and second screens, can be reconfigured (i.e., its position and / or dimensions can be changed) by moving it relative to each other and / or relative to the spectrometer. This allows for a compact arrangement for repositioning and / or changing the dimensions of the confocal aperture. This allows for changing the confocal performance of the spectrometer. For example, a set of relatively small slits (or elongated apertures) in the first and second screens can generate a number of confocal apertures of different dimensions. By arranging the first and second screens to form a reconfigurable confocal aperture at the spectrometer inlet in a spectrometer, it is possible to adjust the spectral resolution of the signal incident on the spectrometer. For example, the resolution of the signal in the first dimension can be controlled independently of the resolution of the signal in the second dimension (vertical dimension). The present invention enables a versatile spectrometer in which the user can set the dimensions and / or position of the confocal aperture based on considerations including desired confocal resolution and / or signal intensity and / or acquisition time.

[0009] Optionally, the first screen includes a further slit, wherein the longitudinal direction of the first slit (in the first screen) is different from the longitudinal direction of the further slit in the first screen and is optionally orthogonal. The second screen includes a further slit, wherein the longitudinal direction of the second slit (in the second screen) is different from the longitudinal direction of the further slit in the second screen and is optionally orthogonal. This allows the first and second slits to be positioned more quickly in the desired location by combining the first slit with the further slit in the second screen (and / or the second slit with the further slit in the first screen), thereby enabling evaluation of a wider sample area for detecting or identifying Raman scattered light before performing longer-duration scanning through the confocal aperture formed by the combination of the first and second slits.

[0010] The first screen and / or the second screen may include a metal substrate, such as a metal foil. For example, a copper substrate, or optionally, copper foil. Optionally, the screen thickness is 50 μm or less, optionally 20-30 μm, or optionally 25 μm.

[0011] Optionally, the first surface of the first screen is in contact with the first surface of the second screen. Optionally, contact between the first and second screens is maintained, but as at least one bend, or optionally a pair of bends. The first bend can bias the first screen toward the second screen. The second bend can bias the second screen toward the first screen. Optionally, the first surface of the first screen and the first surface of the second screen are separated by a distance of 25 μm or less, or optionally 10 μm or less. Optionally, the first and second screens are separated by a separator, such as a PTFE separator. Optionally, the first screen and its first surface, and / or the first surface of the second screen, are coated with a friction-reducing layer, such as a Ni-containing layer.

[0012] Optionally, at least one motor is provided for moving the first screen and the second screen relative to each other. A first motor may be provided for moving the first screen. A second motor may be provided for moving the second screen.

[0013] A module for a spectrometer (optionally a Raman spectrometer) is provided according to a second embodiment, comprising a first screen and a second screen. The first screen includes a first slit, and the second screen includes a second slit, and the first and second screens are movable relative to each other to produce a confocal aperture reconstructible from the first and second slits. The first and second slits are elongated in different directions. Optionally, the first screen is movable relative to other components of the module. Optionally, the second screen is movable relative to other components of the module.

[0014] A spectrometer (optionally a Raman spectrometer) is provided, comprising the module of the second embodiment. Optionally, this module is located at the inlet of the spectrometer's spectrometer.

[0015] A fourth embodiment provides a method for acquiring spectral data, comprising the step of partially aligning (or partially overlapping) a slit in a first screen and a slit in a second screen to create a confocal aperture that penetrates both the first and second screens, wherein the slits in the first and second screens are elongated and extend in different directions.

[0016] A spectrometer is provided that includes a spatial filter for generating a reconfigurable confocal aperture, wherein the spatial filter is located at the entrance of the spectrometer's spectrometer, and the reconfigurable confocal aperture can move in a plane perpendicular to the optical axis of the spectrometer. Here, the spatial filter includes a first screen and a second screen, the first screen including a first slit, and the second screen including a second slit, and the first screen and the second screen are movable relative to each other to generate a reconfigurable and movable confocal aperture from the first slit and the second slit.

[0017] The present invention also provides a spectrometer that may include a first screen and a second screen. Optionally, the first screen includes a first aperture. Optionally, the second screen includes a second aperture. The first screen and the second screen are optionally movable relative to each other to produce a confocal aperture that can be reconstructed from the first and second apertures.

[0018] Features from one aspect can be incorporated into any other aspect. [Brief explanation of the drawing]

[0019] Here, the present invention will be described only as an example, with reference to the following drawings.

[0020] [Figure 1] This figure shows a schematic representation of one embodiment of a Raman spectrometer. [Figure 2] This figure shows a schematic representation of a reconfigurable confocal aperture in different configurations. [Figure 3(a)] This is a plan view showing a screen for forming a reconfigurable opening. [Figure 3(b)] This diagram shows the first and second screens. [Figure 4] This is an alternative diagram of the screen in Figure 3(a). [Figure 5] This diagram shows a module with a reconfigurable confocal aperture. [Figure 6] This is a plan view showing the module in Figure 5. [Modes for carrying out the invention]

[0021] Figure 1 shows a first embodiment of a Raman spectrometer according to the present invention. The input laser beam 10 is reflected at a 90° angle by a dichroic filter 12 positioned at a 45° angle with respect to the optical path. The laser beam 10 then passes through a spatial filter 14, which includes a first screen 31A and a second screen 31B positioned between a first lens 32 and a second lens 34. The first screen 31A includes a first slit 312 extending perpendicular to the plane of the paper (as shown in Figure 2). The second screen 31B includes a second slit 314 extending in the plane of the paper and perpendicular to the direction of propagation of the laser beam (as shown in Figure 2). The second screen 31B is indicated by a dashed line because the plane of the paper coincides with the second slit 314. Light can pass through an aperture 30 where the first slit 312 and the second slit 314 coincide (partially overlap). The aperture 30 is a confocal aperture. The second lens 34 focuses the parallel laser beam 10 to a narrow focal point that allows it to pass through the confocal aperture 30 formed by the first screen 31A and the second screen 31B. The first lens 32 converts the laser beam back into a parallel beam. The laser beam 10 then passes through the microscope objective lens 16, which focuses the laser beam to a single point at a focal point 19 on the sample 18. At this point of illumination, the light is scattered by the sample, focused by the microscope objective lens 16, and converted into a parallel beam that passes back into the spatial filter 14. The first lens 32 focuses the scattered parallel beam to a narrow focal point that passes through the aperture 30 formed by the combination of the first slit 312 in the first screen 31A and the second slit 314 in the second screen 31B. The second lens 34 converts the light back into a scattered parallel beam. The effect of the aperture 30 is that the microscope objective lens 16 acts confocally. That is, essentially only the light scattered at the focal point 19 of the lens 16 passes through the aperture 30.The dashed line 36 shown in Figure 1 illustrates the situation for light scattered from a location other than the focal point 19, in this case, light scattered between the microscope objective lens 16 and the focal point 19. Figure 1 shows that this light, corresponding to the dashed line 36, is substantially blocked by the screens 31A and 31B because it does not result in focus at the aperture 30. The same applies to light scattered far from the focal point 19 relative to the microscope objective lens 16. Light from the second lens 34 is sent to a dichroism filter 12 that removes Rayleigh scattered light (elastic scattered light having the same wavelength as the input laser beam 10). The dichroism filter 12 transmits Raman scattered light. The Raman scattered light is sent to a Raman analyzer 20. The Raman analyzer 20 may include an adjustable non-dispersive filter for selecting the target Raman rays. Alternatively, the Raman analyzer 20 may include a dispersion element such as a diffraction grating. Light from the Raman analyzer 20 is focused onto a suitable photodetector 24 by a lens 22. In this embodiment, a CCD (charge-coupled device) 24 including a two-dimensional pixel array is used, and the CCD 24 is connected to a computer 25, which collects data from each of the pixel groups and analyzes the data as needed. If the Raman analyzer 20 has an adjustable non-dispersive filter, light of the selected Raman frequency is focused at a point 26 on the CCD 24. If the Raman analyzer 20 has a dispersive element (such as a diffraction grating), the analyzer 20 generates a spectrum with various bandwidths, as indicated by a dashed line 28 extending along a line on the CCD 24.

[0022] In the embodiment of Figure 1, the first screen 31A and the second screen 31B can move relatively to each other and to other components of the spectrometer. In the illustrated embodiment, the first screen 31A can move back and forth along an axis that coincides with the plane of the first screen 31A and is perpendicular to the longitudinal direction of the first slit 312 in the first screen 31A. This enables the first slit 312 to move (back and forth) along the first direction 202 (shown in Figure 2) relatively to the second screen 31B. The second screen 31B can move back and forth along an axis that coincides with the plane of the second screen 31B and is perpendicular to the longitudinal direction of the second slit 314 in the second screen 31B. This enables the second slit 314 to move (back and forth) along the second direction 204 (shown in Figure 2) relatively to the first screen 31A.

[0023] As shown in Figure 1, the first screen 31A and the second screen 31B are arranged in parallel planes. Each plane of the first screen 31A and the second screen 31B is perpendicular to the optical axis of the spectrometer. Each plane of the first screen 31A and the second screen 31B is perpendicular to the optical axis of the objective lens 16. Each plane of the first screen 31A and the second screen 31B is perpendicular to the respective optical axes of the first lens 32 and the second lens 34.

[0024] In the illustrated embodiment, it is possible to move the first screen 31A relatively to other components of the spectrometer including the second screen 31B. It is also possible to move the second screen relatively to other components of the spectrometer including the first screen 31A. This enables each of the first screen 31A and the second screen 31B to move relatively to the other of the first screen 31A and the second screen 31B.

[0025] Figure 2 illustrates how the spatial filter 14 is reconfigured by rearranging the first screen 31A relative to the second screen 31B, thereby enabling the movement of the confocal aperture 30. Figures 2(a) through 2(c) show the first slit 312 moving along the first direction 202 relative to the second slit 314. The second slit 314 is indicated by a dashed line where it is shielded by the first screen 31A. The aperture 30 is formed where the first slit 312 and the second slit 314 coincide (partially overlap). Figures 2(a), 2(d), and 2(e) show the second slit 314 moving along the second direction 204 relative to the first slit 312. In the illustrated embodiment, the first direction 202 and the second direction 204 are orthogonal to each other. For example, as shown in Figure 2(f), the position of the opening 30 can be set by changing the positions of the first slit 312 and the second slit 314.

[0026] In some embodiments, this can allow the opening 30 to be positioned at an infinitely variable number of locations. Here, the position of the first slit 312 can be at any location between the positions illustrated in Figures 2(a) and 2(c), and the position of the second slit 314 can be at any location between the positions illustrated in Figures 2(a) and 2(e). In other embodiments, the positions of the first slit 312 and the second slit 314 can be indexed so that the position of the opening 30 is determined by the positions that the first slit 312 can occupy between the positions illustrated in Figures 2(a) and 2(c), and the positions that the second slit 314 can occupy between the positions illustrated in Figures 2(a) and 2(e).

[0027] Figure 1 also shows an alternative arrangement of components within the Raman spectrometer. In this alternative embodiment, the dichroism filter 12A is positioned between the spatial filter 14 and the microscope objective lens 16 (instead of the position of the dichroism filter 12). By positioning the dichroism filter 12A between the spatial filter 14 and the microscope objective lens 16, the spatial filter is positioned directly in front of the Raman analyzer 20 (in other words, the spatial filter is positioned at the inlet to the spectrometer). The laser beam 10A is incident on the dichroism filter 12A and reflected at a 90° angle by the dichroism filter 12A, which is positioned at a 45° angle to the optical path. The laser beam 10A then passes through the microscope objective lens 16, which focuses the laser beam onto a spot 19 on the sample 18. By positioning the spatial filter 14 at the inlet to the spectrometer, the spatial filter can be used to control the resolution of the signal sent to the spectrometer / Raman analyzer 20. A further advantage of the arrangement with the dichroism filter at position 12A is that the input laser beam 10A does not need to pass through the spatial filter 14, thus eliminating the risk of the input laser hitting the edge of the aperture 30 and scattering. However, in a configuration where the dichroism filter is located at position 12 (instead of position 12A), the input laser 10 can be used when adjusting the spatial filter 14 during setup.

[0028] In the current embodiment, the first screen 31A and the second screen 31B are held in contact with each other and maintain contact even while the first screen 31A and the second screen 31B are moved relative to each other to move the first slit 312 in a first direction and / or move the second slit 314 in a second direction 204. A bend (not shown) is used to maintain secure contact between the first screen 31A and the second screen 31B. In this embodiment, the first bend biases the first screen 31A toward the second screen 31B, and the second bend biases the second screen 31B toward the first screen 31A. The first screen 31A and the second screen 31B are copper foils. Both the first screen 31A and the second screen 31B have surfaces that contact the other screen, and the contact surfaces of both the first screen 31A and the second screen 31B have an electroformed nickel layer, which can reduce friction between the first screen 31A and the second screen 31B. In other embodiments, the first screen 31A and the second screen 31B may be spaced apart and separated by a spacer, for example, a PTFE spacer. In embodiments where the first screen 31A and the second screen 31B are spaced apart, the distance between the surface of the first screen 31A facing the second screen 31B and the surface of the second screen 31B facing the first screen 31A may be 25 μm or less.

[0029] Figure 3(a) shows a plan view of one embodiment of the screen 3100, which in this case has the shape of a foil 3100. Figure 4 shows an orthographic projection of the foil 3100 in Figure 3(a). The foil 3100 is a copper foil containing a nickel layer on one side, and the nickel layer is electroformed. The foil 3100 shown in Figure 3 extends in the length direction 3120 and the width direction 3122. The foil 3100 also has thickness in directions perpendicular to the length and width directions. In this embodiment, the foil 3100 has a thickness of 50 μm or less, a length of about 20 mm (along the direction 3120), and a thickness of about 10 mm (along the direction 3122). In the thickness direction, five slits 3102, 3104, 3106, 3108, and 3110 extend through the foil 3100. Four of the slits 3102, 3104, 3106, and 3108 extend elongatedly in the width direction 3122 of the foil 3100, extending 2 mm in the width direction (in other words, the lengths of slits 3102, 3104, 3106, and 3108 are each 2 mm). Slits 3102, 3104, 3106, and 3108 have different dimensions in the length direction 3120 of the foil 3100. Slit 3102 extends 10 μm in the longitudinal direction 3120 of the foil 3100 (in other words, the width of slit 3102 is 10 μm), slit 3104 extends 20 μm in the longitudinal direction 3120 of the foil 3100 (in other words, the width of slit 3104 is 20 μm), slit 3106 extends 65 μm in the longitudinal direction 3120 of the foil 3100 (in other words, the width of slit 3106 is 65 μm), and slit 3108 extends 100 μm in the longitudinal direction 3120 of the foil 3100 (in other words, the width of slit 3108 is 100 μm). The fifth slit 3110 in the foil 3100 has a length of 2 mm in the longitudinal direction 3120 of the foil 3100 and a width of 1 mm in the width direction 3122 of the foil 3100. Figure 3(b) shows the first foil 3100A being superimposed on the second foil 3100B. Both the first foil 3100A and the second foil 3100B are foil 3100.

[0030] Figure 5 illustrates a spectrometer module 500 comprising a pair of screens 3100, the first screen 3100A being illustrated within a first carriage 502. The first carriage 502 is movable in the x-direction by a first motor 506. A first encoder 504 is shown to measure the x-direction position of the first screen 3100A. The second screen 3100B is positioned next to the first screen 3100A and rotated at an angle of 90° in the xy-plane (as shown in Figure 3(b)). Furthermore, the first screen 3100A and the second screen 3100B are positioned such that the nickel-plated surface of the first screen 3100A and the nickel-plated surface of the second screen 3100B face each other. The second screen 3100B is located within a second carriage, which is movable in the y-direction by a motor 508, and a second encoder 510 is shown to measure the y-direction position of the second screen 3100B. Figure 6 shows a plan view of module 500 shown in Figure 5.

[0031] During use, the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, can be combined (partially overlapped) with any of the slits 3102, 3104, 3106, 3108, or 3110 of the second screen 3100B. This can be achieved by controlling the relative positions of the first screen 3100A and the second screen 3100B by moving the first screen 3100A in the x-direction and / or moving the second screen 3100B in the y-direction. When the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, is combined with slit 3102 of the second screen 3100B, an opening is formed that allows light transmission to both the first screen 3100A and the second screen 3100B, having a width of 10 μm in the x-direction and a width of 10 μm in the y-direction. Similar to the method shown in Figure 2, the position of this opening can be further controlled by moving the first screen 3100A in the x-direction and the second screen 3100B in the y-direction.

[0032] When the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, is combined with the slit 3104 of the second screen 3100B, an opening is formed that allows light transmission to both the first screen 3100A and the second screen 3100B, having a width of 10 μm in the x-direction and a width of 20 μm in the y-direction. Similar to the method shown in Figure 2, the position of this opening can be further controlled by moving the first screen 3100A in the x-direction and the second screen 3100B in the y-direction.

[0033] When the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, is combined with the slit 3106 of the second screen 3100B, an opening is formed that allows light transmission to both the first screen 3100A and the second screen 3100B, having a width of 10 μm in the x-direction and a width of 65 μm in the y-direction. Similar to the method shown in Figure 2, the position of the opening can be further controlled by moving the first screen 3100A in the x-direction and the second screen 3100B in the y-direction.

[0034] When the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, is combined with the slit 3108 of the second screen 3100B, an opening is formed that allows light transmission to both the first screen 3100A and the second screen 3100B, having a width of 10 μm in the x-direction and a width of 100 μm in the y-direction. Similar to the method shown in Figure 2, the position of this opening can be further controlled by moving the first screen 3100A in the x-direction and the second screen 3100B in the y-direction.

[0035] When the first slit of the first screen 3100A, having a width of 10 μm in the x-direction, is combined with the slit 3110 of the second screen 3100B, an opening is formed that allows light transmission to both the first screen 3100A and the second screen 3100B, having a width of 10 μm in the x-direction and a width of 2 mm in the y-direction. The position of this opening can be further controlled by moving the first screen 3100A in the x-direction and the second screen 3100B in the y-direction, similar to the method shown in Figure 2.

[0036] The second slit of the first screen 3100A, with a width of 20 μm in the x-direction, can be combined with any of the slits 3102, 3104, 3106, 3108, or 3110 of the second screen 3100B. Therefore, by combining the module 500 with slits 3102, 3104, 3106, 3108, or 3110, it is possible to form a position-adjustable opening that allows light transmission with a width of 20 μm in the x-direction and widths of 10 μm, 20 μm, 65 μm, 100 μm, or 2 mm in the y-direction.

[0037] The third slit of the first screen 3100A, having a width of 65 μm in the x-direction, can be combined with any of the slits 3102, 3104, 3106, 3108, or 3110 of the second screen 3100B. Therefore, the module 500, when combined with slits 3102, 3104, 3106, 3108, or 3110 respectively, can create a position-adjustable opening that allows light transmission with a width of 65 μm in the x-direction and widths of 10 μm, 20 μm, 65 μm, 100 μm, or 1 mm in the y-direction.

[0038] The fourth slit of the first screen 3100A, having a width of 100 μm in the x-direction, can be combined with any of the slits 3102, 3104, 3106, 3108, or 3110 of the second screen 3100B. Therefore, by combining the module 500 with slits 3102, 3104, 3106, 3108, or 3110 respectively, it is possible to form a position-adjustable opening that allows light transmission, having a width of 100 μm in the x-direction and widths of 10 μm, 20 μm, 65 μm, 100 μm, or 2 mm in the y-direction.

[0039] The fifth slit of the first screen 3100A, having an x-direction dimension of 2 mm, can be combined with any of the slits 3102, 3104, 3106, or 3108 of the second screen 3100B. Therefore, by combining module 500 with slits 3102, 3104, 3106, or 3108 respectively, it is possible to create a position-adjustable opening that allows light transmission with a width of 2 mm in the x-direction and widths of 10 μm, 20 μm, 65 μm, or 100 μm in the y-direction. The fifth slit of the first screen 3100A, having an x-direction dimension of 2 mm, can be combined with slit 3110 of the second screen 3100B as a position-adjustable opening that allows light transmission with a maximum width of 1 mm in the x-direction and a maximum width of 1 mm in the y-direction.

[0040] Therefore, it can be seen that Module 500 can enable the selection of multiple aperture dimensions and aperture positions and can be used as part of a spatial filter in a spectrometer, particularly a Raman spectrometer. In particular, the apertures that Module 500 can generate can enable variations in the confocal performance of the spectrometer. For example, an aperture with a unidirectional dimension of 10 μm can be used to provide a proof statement of confocality and to achieve high spectral resolution, an aperture with a unidirectional dimension of 20 μm can be used for general confocal applications, and an aperture with a unidirectional dimension of 100 μm can be used for high-sensitivity confocal applications where the amount of Raman scattered light generated by irradiation of the sample is small. An aperture with a unidirectional dimension of 65 μm can be used to generate an intermediate signal between an aperture with a dimension of 20 μm and an aperture with a dimension of 100 μm. An aperture with a unidirectional dimension of 1 mm can be used to quickly identify the target area and align the spectrometer before switching to an aperture with a smaller dimension. An aperture with a dimension of 2 mm can also be used for line focusing. For example, to form a confocal slit, a slit 3110 in either the first or second screen can be used for one of the apertures 3102, 3104, 3106, or 3108 in the other of the first or second screen. Thus, providing multiple apertures of different dimensions makes it possible to change the confocality of the spectrometer according to the user's needs.

[0041] The embodiment shown in Figure 1 is described in which a dichroism filter 12 (or 12A) is positioned at a 45° angle to the input laser beam 10 (10A) to reflect the laser beam at a 90° angle so that it is coaxial with the optical axis of the lens 16, but in other embodiments this is not necessarily the case. In other embodiments, the dichroism filter 12 (12A) may be positioned at an angle other than 45°, and the input laser beam 10 (10A) may be positioned at an angle different from the angle shown in Figure 1. In such embodiments, the laser beam is reflected by the dichroism filter so that it is coaxial with the optical axis of the lens 16. In such embodiments, it may be advantageous to have further optical features that improve the performance of the filter, such as disclosed in EP0543578B1, for example. In yet another embodiment, the input laser beam may be reflected by a reflective element other than the dichroism filter, such as a mirror, so that it is coaxial with the optical axis of the lens 16. In such embodiments, the reflecting element may be positioned at a 45° angle to the input laser beam, similar to the situation shown in Figure 1, or in other embodiments, the reflecting element and the input laser beam may have a different arrangement (from that shown in Figure 1), and the input laser beam is reflected by the reflecting element, thereby making the laser beam coaxial with the optical axis of the lens 16.

Claims

1. A spectrometer comprising a first screen and a second screen, The first screen includes a first slit, The second screen includes a second slit, The first screen and the second screen are movable relative to each other in order to generate a confocal aperture that can be reconstructed from the first slit and the second slit. The first slit and the second slit extend elongated in different directions. Spectrometer.

2. The spectrometer according to claim 1, wherein the first screen and the second screen are arranged at the inlet of the spectrometer to generate the reconfigurable confocal aperture.

3. The spectrometer according to claim 2, wherein the first slit and the second slit are elongated in an orthogonal direction.

4. The spectrometer according to any one of claims 1 to 3, wherein the first screen includes a plurality of first slits.

5. The spectrometer according to any one of claims 1 to 4, wherein the second screen includes a plurality of second slits.

6. The spectrometer according to any one of claims 1 to 4, wherein the first screen includes a further slit, and the longitudinal direction of the first slit in the first screen and the longitudinal direction of the further slit in the first screen are different and optionally orthogonal.

7. The spectrometer according to any one of claims 1 to 5, wherein the second screen includes a further slit, and the longitudinal direction of the second slit in the second screen is different from the longitudinal direction of the further slit in the second screen, and optionally orthogonal.

8. The spectrometer according to any one of claims 1 to 7, wherein the first screen and / or the second screen includes a copper substrate.

9. The spectrometer according to any one of claims 1 to 8, wherein the first surface of the first screen is in contact with the first surface of the second screen.

10. The spectrometer according to claim 9, wherein the first surface of the first screen and / or the first surface of the second screen are coated with a Ni-containing layer.

11. The spectrometer according to any one of claims 1 to 10, comprising at least one motor for moving the first screen and the second screen relative to each other.

12. A spectrometer module comprising a first screen and a second screen, The first screen includes a first slit, The second screen includes a second slit, The first screen and the second screen are movable relative to each other in order to generate a confocal aperture that can be reconstructed from the first slit and the second slit. The first slit and the second slit extend elongated in different directions. Module.

13. The module according to claim 12, wherein the first slit and the second slit extend elongated in an orthogonal direction.

14. The module according to claim 12 or 13, wherein the first screen includes a plurality of first slits, and / or the second screen includes a plurality of second slits.

15. A method for collecting spectral data, The step of partially aligning a slit in the first screen with a slit in the second screen to create a confocal aperture that penetrates the first screen and the second screen. Equipped with, The slit in the first screen and the slit in the second screen extend in different directions. method.

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