Ultra-wide two-dimensional field-of-view and ultra-high spectral resolution imaging spectrometer based on grating beam splitter interferometer

Abstract

The present invention discloses an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, belonging to the field of spectral imaging technology. The imaging spectrometer comprises: a first microlens array, a second microlens array, a grating beam splitter interferometer, and a detector. The grating beam splitter interferometer comprises: a first concave reflector, a second concave reflector, a fixed plane mirror, a movable corner reflector, and a plane transmission grating. The first microlens array is used to transmit incident light to the second microlens array for collimation via multiple optical fibers. Each column of first microlenses is arranged on an arc in a different vertical plane, and each row of first microlenses is arranged on an arc in a different horizontal plane, thereby obtaining a two-dimensional ultra-wide field of view. The present invention uses a plane transmission grating in the grating beam splitter interferometer, which is beneficial for cost savings. The use of a movable corner reflector as a moving component effectively eliminates the influence of the tilt and lateral movement of the moving mirror on the sampled interference pattern during the scanning process.

Description

Technical Field

[0001] The present invention belongs to the technical field of spectral imaging, and in particular relates to an ultra-wide two-dimensional field-of-view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer. Background Art

[0002] Imaging spectrometers combine imaging and spectroscopy techniques to simultaneously acquire both spatial and spectral information about an object or scene. Field of view, spectral resolution, spectral range, and spatial resolution are key performance parameters for imaging spectrometers. Since the advent of imaging spectrometers, achieving both a two-dimensional ultra-wide field of view and ultra-high spectral resolution in both the horizontal and vertical planes has been a technical challenge in this field.

[0003] Currently, optical sensors achieve ultra-wide fields of view primarily through four approaches: using fisheye lenses, reflective panoramic lenses, or a combination of the two; using an artificial compound eye; using a single-core multiscale camera; and using a panoramic single-core fiber-coupled imager. However, these methods struggle to obtain high-resolution spectral information. Ultra-high spectral resolution is primarily achieved by spectrometers based on Michelson or Fabry-Perot interferometers, most of which lack an ultra-wide field of view. Due to these limitations, some existing imaging spectrometers can only achieve ultra-high spectral resolution and a one-dimensional ultra-wide field of view simultaneously through scanning, and are unable to achieve a two-dimensional ultra-wide field of view. Summary of the Invention

[0004] To address the above-mentioned problems in the prior art, the present invention provides an ultra-wide two-dimensional field-of-view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer. The technical problems to be solved by the present invention are achieved through the following technical solutions:

[0005] The present invention provides an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, comprising: a first microlens array, a second microlens array, a grating beam splitter interferometer and a detector;

[0006] The first microlens array is configured to transmit incident light to the second microlens array via a plurality of optical fibers; the first microlens array comprises a plurality of first microlenses, wherein each column of the first microlenses is arranged on an arc in a different vertical plane, and each row of the first microlenses is arranged on an arc in a different horizontal plane;

[0007] The second microlens array is used to convert the incident light from each optical fiber into a parallel light beam;

[0008] The grating beam splitter interferometer includes: a first concave reflecting mirror, a second concave reflecting mirror, a fixed plane mirror, a movable angle reflecting mirror and a plane transmission grating; wherein the plane transmission grating is used to diffract the parallel light beam once to generate zero-order diffraction light and first-order diffraction light, and to diffract the reflected zero-order diffraction light and first-order diffraction light twice to generate first-order diffraction light of zero-order diffraction light and zero-order diffraction light of first-order diffraction light; the first concave reflecting mirror is used to reflect the first-order diffraction light obtained by the first diffraction back to the plane transmission grating; the movable angle reflecting mirror is used to, in combination with the fixed plane mirror, reflect the zero-order diffraction light obtained by the first diffraction back to the plane transmission grating during movement; the second concave reflecting mirror is used to focus the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light onto the detector;

[0009] The detector is used to generate multiple interference patterns according to the first-order diffraction light of the received zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light within one scanning cycle of the movable corner reflector to obtain spatial information and spectral information.

[0010] In one embodiment of the present invention, the optical path difference between the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light is four times the displacement of the movable corner reflector from the zero optical path difference position.

[0011] In one embodiment of the present invention, the plane where the parallel light beam is located is a first horizontal plane, the second microlens array includes a plurality of second microlenses arranged along a preset direction in the first horizontal plane, the preset direction is perpendicular to the optical path of the parallel light beam, and the plurality of first microlenses are connected to the plurality of second microlenses via a plurality of optical fibers.

[0012] In one embodiment of the present invention, the first microlens array includes N first microlenses, and the N first microlenses are arranged in columns Q1 and rows Q2, wherein: represents the field of view angle of the first microlens, Φ1 and Φ2 represent the field of view angle of the horizontal plane and the field of view angle of the vertical plane of the imaging spectrometer respectively.

[0013] In one embodiment of the present invention, the second microlens array includes N second microlenses;

[0014] In the first microlens array, the Q2 first microlenses located in the nth column are respectively connected to the (n-1)·Q2+1, (n-1)·Q2+2, ..., nQ2 second microlenses in the second microlens array through optical fibers, where n=1, 2, ..., Q1.

[0015] In one embodiment of the present invention, the detector includes N detection units;

[0016] Each of the detection units is used to receive the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light generated based on the incident light transmitted by the corresponding first microlens within a scanning cycle of the movable corner reflector, and generate an interference pattern to obtain the spatial information and spectral information of the partial field of view corresponding to the interference pattern.

[0017] In one embodiment of the present invention, the detector includes 2 rows and 2N columns of pixels, and each of the detection units includes 2×2 pixels.

[0018] In one embodiment of the present invention, the aperture size of the first microlens is R1 represents the radius of the arc formed by each column of the first microlens in the first microlens array;

[0019] The incident half angle θ of the optical fiber in And the clear aperture size D1 of the first microlens satisfies:

[0020]

[0021] Wherein, f1 represents the focal length of the first microlens.

[0022] In one embodiment of the present invention, the optical fiber has an emission half-angle θ out And the clear aperture size D2 of the second microlens satisfies:

[0023]

[0024] D2≥f2 tan(θ out );

[0025] Wherein, f2 represents the focal length of the second microlens, n o Represents the refractive index of the medium, N A represents the numerical aperture of the optical fiber.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present invention provides an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, comprising: a first microlens array, a second microlens array, a grating beam splitter interferometer, and a detector. The first microlens array is configured to transmit incident light to a second microlens array for collimation via multiple optical fibers. Each column of the first microlenses in the first microlens array is arranged on arcs in different vertical planes, thereby achieving an ultra-wide field of view in the vertical plane. Each row of the first microlenses in the first microlens array is arranged on arcs in different horizontal planes, thereby achieving an ultra-wide field of view in the horizontal plane, thereby achieving a two-dimensional ultra-wide field of view. Furthermore, the present invention uses a planar transmission grating in place of a beam splitter in the grating beam splitter interferometer, thereby saving costs. The use of a movable corner reflector as a moving component effectively eliminates the effects of the tilt and lateral movement of the moving mirror on the sampled interferogram during scanning.

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the structure of an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by an embodiment of the present invention;

[0030] Figure 2 is an equivalent cross-sectional view of the first microlens array and the second microlens array provided by an embodiment of the present invention on a horizontal plane;

[0031] Figure 3 1 is an equivalent cross-sectional view of a first microlens array on a vertical plane and a schematic diagram of the position of a second microlens array on a horizontal plane provided by an embodiment of the present invention;

[0032] Figure 4 1 is a schematic diagram of the principle of a grating beam splitter interferometer provided by an embodiment of the present invention;

[0033] Figure 5 This is a partial equivalent optical path diagram on the meridional plane of an ultra-wide two-dimensional field-of-view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by an embodiment of the present invention;

[0034] Figure 6 It is a restored spectrum diagram of the ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by an embodiment of the present invention;

[0035] Figure 7 yes Figure 6 The local image of a narrow band wave in the restored spectrum shown. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0037] At present, existing imaging spectrometers can either only achieve ultra-high spectral resolution and cannot achieve even a one-dimensional ultra-wide field of view, or can only achieve ultra-high spectral resolution and a one-dimensional ultra-wide field of view on a certain plane at the same time. In other words, existing imaging spectrometers cannot simultaneously achieve ultra-high spectral resolution and a two-dimensional (horizontal and vertical) ultra-wide field of view.

[0038] In view of this, an embodiment of the present invention provides an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer.

[0039] Figure 1 Schematic diagram of the structure of an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by an embodiment of the present invention. Figure 1 As shown, an embodiment of the present invention provides an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer 1 based on a grating beam splitter interferometer, comprising: a first microlens array 10, a second microlens array 20, a grating beam splitter interferometer 30 and a detector 40;

[0040] The first microlens array 10 is configured to transmit incident light to the second microlens array 20 via a plurality of optical fibers. The first microlens array 10 includes a plurality of first microlenses 101 , wherein each column of the first microlenses 101 is arranged on an arc in a different vertical plane, and each row of the first microlenses 101 is arranged on an arc in a different horizontal plane.

[0041] a second microlens array 20, for converting incident light from each optical fiber into a parallel beam;

[0042] The grating beam splitter interferometer 30 includes: a first concave reflecting mirror 301, a second concave reflecting mirror 302, a fixed plane mirror 303, a movable corner reflecting mirror 304 and a plane transmission grating 305; wherein the plane transmission grating 305 is used to diffract the parallel light beam once to generate zero-order diffraction light and first-order diffraction light, and to diffract the reflected zero-order diffraction light and first-order diffraction light twice to generate first-order diffraction light of the zero-order diffraction light and zero-order diffraction light of the first-order diffraction light; the first concave reflecting mirror 301 is used to reflect the first-order diffraction light obtained by the first diffraction back to the plane transmission grating 305; the movable corner reflecting mirror 304 is used to reflect the zero-order diffraction light obtained by the first diffraction back to the plane transmission grating 305 in combination with the fixed plane mirror 303 during the movement process; the second concave reflecting mirror 302 is used to focus the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light onto the detector 40;

[0043] The detector 40 is used to generate multiple interference patterns according to the first-order diffraction light of the received zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light within one scanning cycle of the movable corner reflector 304, so as to obtain spatial information and spectral information.

[0044] Optionally, in the above-mentioned ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer 1 based on the grating beam splitter interferometer 30, the second microlens array 20 includes a plurality of second microlenses 201 arranged along a preset direction in a first horizontal plane, the preset direction is perpendicular to the optical path of the parallel light beam, and the plurality of first microlenses 101 are connected to the plurality of second microlenses 201 through a plurality of optical fibers.

[0045] Specifically, the first microlens array 10 includes a plurality of first microlenses 101 arranged in rows and columns. The first microlenses 101 in each column are arranged on arcs in different vertical planes, which can obtain an ultra-wide field of view in the vertical plane. The first microlenses 101 in each row are arranged on arcs in different horizontal planes, which can obtain an ultra-wide field of view in the horizontal plane, thereby obtaining a two-dimensional ultra-large field of view in the horizontal and vertical planes. The second microlens array 20 includes a plurality of second microlenses 201 arranged in a straight line in the first horizontal plane. The second microlenses 201 are collimating lenses. When the first microlens array 10 receives incident light, the multiple first microlenses 101 can transmit the incident light to each second microlens 201 via optical fibers, thereby converting the incident light from each optical fiber into a thin parallel light beam. In other words, each optical fiber is connected to a first microlens 101 and a second microlens 201 at both ends. The plane transmission grating 305 is located on the side of the second microlens array 20 away from the first microlens array 10, and the thin parallel light beam can be perpendicularly incident on the plane transmission grating 305.

[0046] Optionally, in this embodiment, the plane where the planar transmission grating 305 is located is defined as a first vertical plane, the different vertical planes where the first microlenses in each column of the first microlens array 1 are located are all parallel to the first vertical plane, the plane formed by the above-mentioned multiple parallel light beams is defined as a first horizontal plane, the different horizontal planes where the first microlenses in each row of the first microlens array 1 are located are all parallel to the first horizontal plane, and the plane perpendicular to the first horizontal plane and the first vertical plane is defined as a first surface. For ease of understanding, please refer to Figure 2 The equivalent cross-sectional view of the first microlens array 10 and the second microlens array 20 on the horizontal plane is shown, and Figure 3 As shown in the equivalent cross-sectional view of the first microlens array 10 on the vertical plane and the schematic diagram of the position of the second microlens array 20 on the horizontal plane, it can be seen that the first microlenses 101 in each column are arranged to form an arc in the corresponding vertical plane, and the first microlenses 101 in each row are arranged to form an arc in the corresponding horizontal plane. Therefore, the orthographic projections of the first microlenses 101 in each row on the first horizontal plane and the orthographic projections of the first microlenses 101 in each column on the first surface are both arc-shaped, and the second microlens array 20 is arranged in a row along a preset direction in the first horizontal plane.

[0047] In this embodiment, the first microlens array 10 includes N first microlenses 101, and the N first microlenses 101 are arranged in columns Q1 and rows Q2, wherein: represents the field of view of the first microlens 101 , Φ1 and Φ2 represent the field of view of the imaging spectrometer 1 in the horizontal plane and in the vertical plane, respectively.

[0048] Furthermore, the second microlens array 20 includes N second microlenses 201;

[0049] like Figure 2 As shown, in the first microlens array 10, the Q2 first microlenses 101 located in the nth column are connected to the (n-1)·Q2+1, (n-1)·Q2+2, ..., nQ2 second microlenses 201 in the second microlens array 20 through optical fibers, respectively, where n=1, 2, ..., Q1, Figure 2 In FIG. 1 , W represents the width corresponding to the plurality of second microlenses 201 connected to a certain column of first microlenses 101 in the first microlens array 10 .

[0050] It should be noted that, in this embodiment, the number of the first micro-lenses 101 and the second micro-lenses 201 can be flexibly adjusted according to actual needs, and this application does not impose any limitation on this.

[0051] In this embodiment, the aperture size of the first microlens 101 is R1 represents the radius of the arc formed by each column of the first microlenses 101 in the first microlens array 10;

[0052] Fiber incident half angle θ in And the clear aperture size D1 of the first microlens 101 satisfies:

[0053]

[0054] Wherein, f1 represents the focal length of the first microlens 101 .

[0055] The optical fiber's emission half-angle θ out And the clear aperture size D2 of the second microlens 201 satisfies:

[0056]

[0057] D2≥f2 tan(θ out );

[0058] Wherein, f2 represents the focal length of the second microlens 201, n o Represents the refractive index of the medium, N A Indicates the numerical aperture of the optical fiber.

[0059] Figure 4FIG. 1 is a schematic diagram of the principle of the grating beam splitter interferometer 30 provided by an embodiment of the present invention. Figure 4 As shown, after entering the plane transmission grating 305, the parallel light beam undergoes diffraction, including zero-order diffraction and first-order diffraction. The movable angle reflector 304 and the first concave mirror 301 reflect the resulting zero-order diffraction light and first-order diffraction light back to the plane transmission grating 305, respectively. When the zero-order diffraction light and the first-order diffraction light pass through the plane transmission grating 305, zero-order diffraction and first-order diffraction occur, respectively. The first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light have the same propagation direction and light intensity, so that the two paths of light in the interferometer have the same energy. In other words, the plane transmission grating 305 acts as a beam splitter.

[0060] Furthermore, the center of curvature of the first concave reflector 301 can coincide with the center of the planar transmission grating 305, ensuring that the optical paths of first-order diffracted light of different wavelengths are identical. The movable corner reflector 304 effectively reduces angular errors that may occur during scanning, thereby effectively reducing modulation errors and phase errors in the sampled interferogram caused by tilting and lateral movement of the moving mirror.

[0061] In this embodiment, the optical path difference between the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light is four times the displacement of the movable corner reflector 304 from the zero optical path difference position. Compared with the Michelson interferometer, the movable corner reflector 304 moves the same displacement, and the imaging spectrometer 1 can obtain higher spectral resolution.

[0062] Figure 5 This is a partial equivalent optical path diagram of the ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on the grating beam splitter interferometer provided by the embodiment of the present invention on the meridional plane, where each ray represents the central ray of a beam with a very small radius. Specifically, Figure 5 As shown, on the left side of the plane transmission grating 305, the black line indicates that the central wavelength is λ c The first-order diffraction light, the red line indicates the wavelength λ i On the right side of the plane transmission grating 305, the black line indicates the central wavelength λ c The first-order diffraction light and the zero-order diffraction light, the red line indicates the wavelength λ i The first-order diffraction light and the zero-order diffraction light, θ1(λ c ) is the central wavelength λ c The diffraction angle of the first-order diffracted light. The grating equation of the plane transmission grating 305 can be expressed as:

[0063]

[0064] Where m represents the diffraction order, d represents the grating constant, is the angle between the incident light and the grating normal,

[0065] Let f3 be the focal length of the second concave reflecting mirror 302, θ m (λ i ) is the wavelength λ i Considering Fraunhofer diffraction, when the incident parallel light beam passes through the grating 305 perpendicular to the incident plane, the transmission efficiency is:

[0066]

[0067] Here, 1-δ and β represent the real and imaginary parts of the refractive index of the grating material, respectively, 2a represents the width of the light-transmitting slit on the plane transmission grating 305, k is the angular wave number (e.g., k = 2π / λ), and A0 is the intensity of the incident light. Considering that the two-path light of the grating interferometer passes through the plane transmission grating twice, the intensity A of the two-path light of the grating beam splitter interferometer 305 is (01) and A (10) It can be expressed as:

[0068]

[0069] Because A (01) =A (10) , indicating that the energy of the incident light beam is evenly distributed between the two light beams.

[0070] In the aforementioned ultra-wide two-dimensional field-of-view, ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, the detector 40 includes N detection units, each of which includes 2 rows and 2N columns of pixels. For example, each detection unit includes 2×2 pixels. It should be understood that the number of pixels in each detection unit in the detector 40 depends on the clear aperture size D2 of the second microlens 201 and the size of each pixel. This application uses a detection unit including 2×2 pixels as an example and is not limited thereto.

[0071] Each detection unit is used to receive the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light generated based on the incident light transmitted by the corresponding first microlens 101 within a scanning cycle of the movable corner reflector 304, and generate an interference pattern to obtain the spatial information and spectral information of the partial field of view corresponding to the interference pattern.

[0072] It should be noted that during the scanning process, the movable angle reflector 304 moves back and forth between the zero optical path difference position and the maximum optical path difference position, and one scanning cycle of the movable angle reflector 304 means: the movable angle reflector 304 moves from the zero optical path difference position to the maximum optical path difference position, or from the maximum optical path difference position to the zero optical path difference position. Figure 1The position of the movable corner reflector 304 indicated by the solid line is the zero optical path difference position, and l is the displacement of the position of the movable corner reflector 304 indicated by the dotted line from the zero optical path difference position.

[0073] In this embodiment, the number of detection units is equal to the number of first microlenses 101 and second microlenses 201. That is, for each first microlens 101, after transmitting the incident light to the corresponding second microlens 201 and plane transmission grating 305 in sequence, it generates zero-order diffraction light and first-order diffraction light. The movable angle reflector 304 and the first concave mirror 301 respectively reflect the zero-order diffraction light and the first-order diffraction light back to the plane transmission grating 305. After diffraction occurs again, the second concave mirror 302 reflects the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light to one detection unit. Since the detection unit and the first microlens 101 also have a one-to-one correspondence, if the detection unit receives the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light reflected by the second concave mirror 302, it means that there is a unit of the object to be measured in the small field of view corresponding to this first microlens, and the spatial information of the unit of the object to be measured is obtained; conversely, if the detection unit does not receive the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light reflected by the second concave mirror 302, it means that there is no unit of the object to be measured in the small field of view corresponding to this first microlens.

[0074] Each of the thin parallel light beams collimated by the second microlens 201 passes through the grating beam splitter interferometer 30 and is focused by the second concave reflector 302 onto the range of 2×2 pixels on the detector. The interference pattern can be given by the following formula:

[0075]

[0076] Wherein, Δ represents the optical path difference, l represents the displacement of the corner reflector to the zero optical path difference position, and Δ=4l, σ represents the wave number, and A0(σ) represents the input spectral intensity at wave number σ.

[0077] According to the Nyquist theorem, to completely reconstruct the original signal, the required sampling frequency must be at least twice the highest frequency of the original signal. Let X be the sampling interval (the inverse of the sampling frequency), the sampling interval can be expressed as:

[0078]

[0079] σ max Indicates the maximum wave number of incident light.

[0080] The theoretical spectral resolution of the imaging spectrometer can be expressed as:

[0081]

[0082] Where, OPD represents the optical path difference, OPD max Indicates the maximum optical path difference, l max represents the maximum displacement of the corner mirror. Considering the influence of the apodization effect on the spectral resolution, the working spectral resolution of the imaging spectrometer can be calculated as:

[0083]

[0084] Let K be the number of sampling points of each interferogram, which is obtained by dividing the maximum optical path difference by the sampling interval. Therefore, K can be expressed as:

[0085] K min =8l max σ max .

[0086] The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by the present invention is further illustrated below through simulation experiments.

[0087] Specifically, the relevant parameters are as follows: the pixel size of the detector 40 is 0.02 mm, the grating constant of the plane transmission grating 305 is 250 lines / mm, the radius of the arc formed by each column of the first microlens 101 in the first microlens array 10 is R1=100 mm, and the theoretical field angle of each first microlens 101 in the first microlens array 10 is The clear aperture size is D1 = 1.05 mm; the clear aperture size of each second microlens 201 in the second microlens array 20 is D2 = 0.04 mm; the focal length f1 of the first microlens 101 is 2 mm, and the focal length f2 of the second microlens 201 is 0.076 mm. The field of view of the imaging spectrometer 1 is Φ1 = 120° in the horizontal plane and Φ2 = 60° in the vertical plane. Figure 6 This is the restored spectrum of the ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on the grating beam splitter interferometer provided by the embodiment of the present invention. Figure 6 As shown, the wavelength range of the incident light is 900nm to 1700nm, which is expressed in wave numbers as 11111.11cm -1 to 5882.35cm -1 The theoretical spectral resolution of the ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer 1 based on grating beam splitter interferometer is 0.05 cm in wave number. -1 , the working spectral resolution is 0.1cm in wavenumber -1 Expressed in terms of wavelength, the spectral resolution for a wavelength of 900 nm is approximately 8.1 pm, the spectral resolution for a wavelength of 1300 nm is approximately 16.9 pm, and the spectral resolution for a wavelength of 1700 nm is approximately 28.9 pm.

[0088] Figure 7yes Figure 6 The figure shows a local image of a narrow band wave in the restored spectrum. Figure 7 As shown, the centers of the five peaks in the restored spectrum are located at 1300.3563 nm, 1300.3732 nm, 1300.3901 nm, 1300.4070 nm and 1300.4239 nm, respectively. It is easy to obtain that the spectral resolution of the 1300 nm wavelength is about 16.9 pm.

[0089] It can be seen from the above simulation results that the ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer 1 based on the grating beam splitter interferometer provided by the present invention can simultaneously obtain an ultra-wide two-dimensional field of view consisting of a field of view angle of 120° on the horizontal plane and a field of view angle of 60° on the vertical plane and an ultra-high spectral resolution of 8.1 picometers to 28.9 picometers in the wavelength range of 900nm to 1700nm.

[0090] It can be seen from the above embodiments that the beneficial effects of the present invention are:

[0091] The present invention provides an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, comprising: a first microlens array, a second microlens array, a grating beam splitter interferometer, and a detector. The first microlens array is configured to transmit incident light to a second microlens array for collimation via multiple optical fibers. Each column of the first microlenses in the first microlens array is arranged on arcs in different vertical planes, thereby achieving an ultra-wide field of view in the vertical plane. Each row of the first microlenses in the first microlens array is arranged on arcs in different horizontal planes, thereby achieving an ultra-wide field of view in the horizontal plane, thereby achieving a two-dimensional ultra-wide field of view. Furthermore, the present invention uses a planar transmission grating in place of a beam splitter in the grating beam splitter interferometer, thereby saving costs. The use of a movable corner reflector as a moving component effectively eliminates the effects of the tilt and lateral movement of the moving mirror on the sampled interferogram during scanning.

[0092] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0093] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0094] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. An ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, characterized in that: include: a first microlens array, a second microlens array, a grating beam splitter interferometer, and a detector; The first microlens array is configured to transmit incident light to the second microlens array via a plurality of optical fibers; the first microlens array comprises a plurality of first microlenses, wherein each column of the first microlenses is arranged on an arc in a different vertical plane, and each row of the first microlenses is arranged on an arc in a different horizontal plane; The second microlens array is used to convert the incident light from each optical fiber into a parallel light beam; The grating beam splitter interferometer includes: a first concave reflecting mirror, a second concave reflecting mirror, a fixed plane mirror, a movable angle reflecting mirror and a plane transmission grating; wherein the plane transmission grating is used to diffract the parallel light beam once to generate zero-order diffraction light and first-order diffraction light, and to diffract the reflected zero-order diffraction light and first-order diffraction light twice to generate first-order diffraction light of zero-order diffraction light and zero-order diffraction light of first-order diffraction light; the first concave reflecting mirror is used to reflect the first-order diffraction light obtained by the first diffraction back to the plane transmission grating; the movable angle reflecting mirror is used to, in combination with the fixed plane mirror, reflect the zero-order diffraction light obtained by the first diffraction back to the plane transmission grating during movement; the second concave reflecting mirror is used to focus the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light onto the detector; The detector is used to generate multiple interference patterns according to the first-order diffraction light of the received zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light within one scanning cycle of the movable corner reflector to obtain spatial information and spectral information.

2. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 1, characterized in that: The optical path difference between the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light is four times the displacement of the movable angle reflector from the zero optical path difference position.

3. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 1, characterized in that: The plane where the parallel light beam is located is a first horizontal plane. The second microlens array includes a plurality of second microlenses arranged along a preset direction in the first horizontal plane. The preset direction is perpendicular to the optical path of the parallel light beam. The plurality of first microlenses are connected to the plurality of second microlenses via a plurality of optical fibers.

4. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 3, characterized in that: The first microlens array includes N first microlenses, and the N first microlenses are arranged in Q1 columns and Q2 rows, wherein: represents the field of view angle of the first microlens, Φ1 and Φ2 represent the field of view angle of the horizontal plane and the field of view angle of the vertical plane of the imaging spectrometer respectively.

5. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 4, characterized in that: The second microlens array includes N second microlenses; In the first microlens array, the Q2 first microlenses located in the nth column are respectively connected to the (n-1)·Q2+1, (n-1)·Q2+2, ..., nQ2 second microlenses in the second microlens array through optical fibers, where n=1, 2, ..., Q1.

6. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 5, characterized in that: The detector includes N detection units; Each of the detection units is used to receive the first-order diffraction light of the zero-order diffraction light and the zero-order diffraction light of the first-order diffraction light generated based on the incident light transmitted by the corresponding first microlens within a scanning cycle of the movable corner reflector, and generate an interference pattern to obtain the spatial information and spectral information of the partial field of view corresponding to the interference pattern.

7. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 6, characterized in that: The detector includes 2 rows and 2N columns of pixels, and each detection unit includes 2×2 pixels.

8. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 7, characterized in that: The aperture size of the first microlens R1 represents the radius of the arc formed by each column of the first microlens in the first microlens array; The incident half angle θ of the optical fiber in And the clear aperture size D1 of the first microlens satisfies: Wherein, f1 represents the focal length of the first microlens.

9. The ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer according to claim 8, characterized in that: The optical fiber's emission half angle θ out And the clear aperture size D2 of the second microlens satisfies: When D2≥f2(θ out ); Wherein, f2 represents the focal length of the second microlens, n o Represents the refractive index of the medium, N A represents the numerical aperture of the optical fiber.

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