Grating beam splitter interferometer-based ultra-wide two-dimensional field-of-view ultra-high spectral resolution imaging spectrometer

Abstract

The invention discloses an ultra-wide two-dimensional field-of-view ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer, which belongs to the technical field of spectral imaging and comprises a first micro-lens array, a second micro-lens array, the 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 micro-lens array is used for transmitting incident light to the second micro-lens array used for collimation through a plurality of optical fibers, each column of first micro-lenses are arranged on arcs in different vertical planes, each row of first micro-lenses are arranged on arcs in different horizontal planes, and a two-dimensional ultra-wide view field can be obtained. The plane transmission grating is used in the grating beam splitter interferometer, the cost is saved, the movable corner reflector is used as a movable part, and the influence of inclination and transverse movement of the movable mirror on a sampling interferogram in the scanning process is effectively eliminated.

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 ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer. Background Art

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

[0003] At present, there are four main ways to achieve ultra-wide field of view for optical sensors: one is to use fisheye lenses, reflective panoramic lenses or a combination of the two; the second is to use artificial compound eyes; the third is to use single-core multi-scale cameras; and the fourth is to use panoramic single-core fiber-coupled imagers. However, these methods are difficult to obtain high-resolution spectral information. Ultra-high spectral resolution is mainly achieved by spectrometers based on Michelson interferometers or Fabry-Perot interferometers, most of which cannot achieve ultra-wide field of view. Due to these limitations, some existing imaging spectrometers can only achieve ultra-high spectral resolution and one-dimensional ultra-wide field of view at the same time through scanning, and cannot obtain a two-dimensional ultra-wide field of view. Summary of the invention

[0004] In order to solve the above problems existing in the prior art, the present invention provides an ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer. The technical problem to be solved by the present invention is achieved by the following technical solutions:

[0005] The present invention provides an ultra-wide two-dimensional field of view 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 used to transmit incident light to the second microlens array through a plurality of optical fibers; the first microlens array comprises a plurality of first microlenses, wherein each column of first microlenses is arranged on arcs in different vertical planes, and each row of first microlenses is arranged on arcs in different horizontal planes;

[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 comprises: 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 reflect the zero-order diffraction light obtained by the first diffraction back to the plane transmission grating in combination with the fixed plane mirror during the 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 a 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 angle 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 of the first microlens, Φ1 and Φ2 represent the field of view of the horizontal plane and 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 connected to the (n-1)·Q2+1, (n-1)·Q2+2, ..., nQ2 second microlenses in the second microlens array through optical fibers, respectively, where n=1, 2, ..., Q1.

[0015] In one embodiment of the present invention, the detector comprises 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 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 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; wherein the first microlens array is used to transmit incident light to the second microlens array for collimation through multiple optical fibers, and each column of the first microlens in the first microlens array is arranged on arcs in different vertical planes, so that an ultra-wide field of view is obtained in the vertical plane, and each row of the first microlens in the first microlens array is arranged on arcs in different horizontal planes, so that an ultra-wide field of view is obtained in the horizontal plane, thereby obtaining a two-dimensional ultra-wide field of view. At the same time, the present invention uses a plane transmission grating instead of a beam splitter in the grating beam splitter interferometer, which is conducive to cost saving, and uses a movable corner reflector as a moving component, which effectively eliminates the influence of the tilt and lateral movement of the moving mirror on the sampling interference pattern during the scanning process.

[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 It is a structural schematic diagram of an ultra-wide two-dimensional field of view and ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided in an embodiment of the present invention;

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

[0031] Figure 3 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 is a schematic diagram of the principle of a grating beam splitter interferometer provided by an embodiment of the present invention;

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

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

[0036] The present invention is further described in detail below with reference to specific embodiments, 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 one-dimensional ultra-wide field of view, or can only achieve ultra-high spectral resolution and one-dimensional ultra-wide field of view on a certain plane at the same time. In other words, existing imaging spectrometers cannot achieve ultra-high spectral resolution and two-dimensional (horizontal and vertical) ultra-wide field of view at the same time.

[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 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 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 used to transmit the incident light to the second microlens array 20 through a plurality of optical fibers; the first microlens array 10 comprises a plurality of first microlenses 101, wherein each column of the first microlenses 101 is arranged on arcs in different vertical planes, and each row of the first microlenses 101 is arranged on arcs in different horizontal planes;

[0041] A second microlens array 20, for converting incident light from each optical fiber into a parallel light 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 angle 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 zero-order diffraction light and zero-order diffraction light of 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 angle 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 a plurality of 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 a 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, and each column of the first microlenses 101 is arranged on arcs in different vertical planes, so that an ultra-wide field of view can be obtained in the vertical plane. Each row of the first microlenses 101 is arranged on arcs in different horizontal planes, so that an ultra-wide field of view can be obtained in the horizontal plane, thereby obtaining a two-dimensional ultra-large field of view on 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, and 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 through the optical fiber, so as to convert the incident light from each optical fiber into a thin parallel light beam. That is to say, the two ends of each optical fiber are respectively connected to a first microlens 101 and a second microlens 201, and 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 vertically incident on the plane transmission grating 305.

[0046] Optionally, in this embodiment, the plane where the plane 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 in the horizontal plane is shown, and Figure 3 From 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 each column of the first microlenses 101 is arranged to form an arc in the corresponding vertical plane, and each row of the first microlenses 101 is arranged to form an arc in the corresponding horizontal plane, so the orthographic projection of each row of the first microlenses 101 on the first horizontal plane and the orthographic projection of each column of the first microlenses 101 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 horizontal plane and the vertical plane of the imaging spectrometer 1 , respectively.

[0048] Further, 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 limit 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] The incident half angle of the optical fiber is θ in And the 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 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 4Schematic diagram of the principle of the grating beam splitter interferometer 30 provided in 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, and the movable angle reflector 304 and the first concave mirror 301 respectively reflect the obtained zero-order diffraction light and first-order diffraction light back to the plane transmission grating 305; 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, wherein 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 of the interferometer have the same energy. In other words, the plane transmission grating 305 plays the role of a beam splitter.

[0060] In addition, the center of curvature of the first concave reflector 301 can coincide with the center of the plane transmission grating 305, ensuring that the optical paths of the first-order diffracted lights of different wavelengths are the same. The movable corner reflector 304 effectively reduces the angle error that may occur during scanning, thereby effectively reducing the modulation error and phase error of the sampling interferogram caused by the tilt 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 a higher spectral resolution.

[0062] Figure 5 It is a partial equivalent optical path diagram of the ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on the grating beam splitter interferometer provided by the embodiment of the present invention on the meridian plane, in which 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 The first-order diffraction light of the plane transmission grating 305 is shown in FIG. 3 , and the black line on the right side of the plane transmission grating 305 indicates that the central wavelength is 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] In the formula, 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 is perpendicular to the incident plane and transmits through the grating 305, 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 (for example, 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 ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on the grating beam splitter interferometer, the detector 40 includes N detection units, and the detector 40 includes 2 rows and 2N columns of pixels. Exemplarily, each detection unit includes 2×2 pixels. It should be understood that the number of pixels of each detection unit in the detector 40 depends on the aperture size D2 of the second microlens 201 and the size of each pixel. The present application only takes the detection unit including 2×2 pixels as an example, and does not limit this.

[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 corner 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 corner reflector 304 means: the movable corner 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 to say, for each first microlens 101, after transmitting the incident light to the corresponding second microlens 201 and the plane transmission grating 305 in sequence, zero-order diffraction light and first-order diffraction light are generated, and 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 reflected by the second concave mirror 302 and the zero-order diffraction light of the first-order diffraction light, it means that there is a unit of the measured object in the small field of view corresponding to the first microlens, and the spatial information of the unit of the measured object 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 measured object in the small field of view corresponding to the first microlens.

[0074] Each thin parallel light beam collimated by the second microlens 201 passes through the grating beam splitter interferometer 30 and is converged by the second concave reflector 302 to 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 the 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), and 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 reflector. 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 interference pattern, 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 the grating beam splitter interferometer provided by the present invention is further illustrated by simulation experiments below.

[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 aperture size is D1=1.05mm; the aperture size of each second microlens 201 in the second microlens array 20 is D2=0.04mm; the focal length f1=2mm of the first microlens 101, and the focal length f2=0.076mm of the second microlens 201. The field of view of the imaging spectrometer 1 is Φ1=120° on the horizontal plane and Φ2=60° on the vertical plane. Figure 6 This is a restored spectrum diagram of the ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on a grating beam splitter interferometer provided by an embodiment of the present invention. Figure 6 As shown, the wavelength of the incident light ranges from 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 a grating beam splitter interferometer is 0.05 cm in wavenumber. -1 The working spectral resolution is expressed in wave numbers as 0.1 cm -1 In terms of wavelength, the spectral resolution for a wavelength of 900 nm is about 8.1 pm, the spectral resolution for a wavelength of 1300 nm is about 16.9 pm, and the spectral resolution for a wavelength of 1700 nm is about 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 1300.3563nm, 1300.3732nm, 1300.3901nm, 1300.4070nm and 1300.4239nm, respectively. It is easy to obtain that the spectral resolution of the 1300nm wavelength is about 16.9pm.

[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 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; wherein the first microlens array is used to transmit incident light to the second microlens array for collimation through multiple optical fibers, and each column of the first microlens in the first microlens array is arranged on arcs in different vertical planes, so that an ultra-wide field of view is obtained in the vertical plane, and each row of the first microlens in the first microlens array is arranged on arcs in different horizontal planes, so that an ultra-wide field of view is obtained in the horizontal plane, thereby obtaining a two-dimensional ultra-wide field of view. At the same time, the present invention uses a plane transmission grating instead of a beam splitter in the grating beam splitter interferometer, which is conducive to cost saving, and uses a movable corner reflector as a moving component, which effectively eliminates the influence of the tilt and lateral movement of the moving mirror on the sampling interference pattern during the scanning process.

[0092] In the description of the present invention, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0093] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means 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 may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0094] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. An ultra-wide two-dimensional field of view 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 used to transmit incident light to the second microlens array through a plurality of optical fibers; the first microlens array comprises a plurality of first microlenses, wherein each column of first microlenses is arranged on arcs in different vertical planes, and each row of first microlenses is arranged on arcs in different horizontal planes; 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 comprises: 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 reflect the zero-order diffraction light obtained by the first diffraction back to the plane transmission grating in combination with the fixed plane mirror during the 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 a scanning cycle of the movable corner reflector to obtain spatial information and spectral information.

2. The ultra-wide two-dimensional field of view 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 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, and 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 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 columns Q1 and rows Q2, wherein: represents the field of view of the first microlens, Φ1 and Φ2 represent the field of view of the horizontal plane and the vertical plane of the imaging spectrometer respectively.

5. The ultra-wide two-dimensional field of view 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 connected to the (n-1)·Q2+1, (n-1)·Q2+2, ..., nQ2 second microlenses in the second microlens array through optical fibers, respectively, where n=1, 2, ..., Q1.

6. The ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on 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 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 of the detection units includes 2×2 pixels.

8. The ultra-wide two-dimensional field of view ultra-high spectral resolution imaging spectrometer based on 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 ultra-high spectral resolution imaging spectrometer based on grating beam splitter interferometer according to claim 8, characterized in that: The optical fiber has an emission half angle θ out And the 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.

Images