A multispectral simultaneous imaging device and imaging method

Abstract

The application discloses a multispectral synchronous imaging device and method. The device comprises a collimating light path for receiving target light and collimating it into a collimated light beam; a step-by-step light splitting part for splitting the collimated light beam output by the collimating light path into single-band light beams of different target wave bands by means of selective transmission and reflection; a reformatting light path for adjusting the light intensity, adjusting the direction and refocusing the single-band light beams output by the step-by-step light splitting part; and an imaging unit for receiving the single-band light beams converged by the reformatting light path and completing synchronous acquisition of single-band light beam images. The application adopts high-reflective narrow-band optical filters, performs a step-by-step wave band separation process by means of selective transmission and reflection, realizes high light intensity utilization and high spectral separation precision, and effectively avoids the problems of light intensity loss and uneven wave band distribution caused by aperture segmentation in the prior art.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of optical imaging and multispectral diagnosis, and particularly relates to a multispectral synchronous imaging device and imaging method. The device is suitable for multidisciplinary research fields such as medical spectral analysis, plasma diagnosis and combustion research, and particularly shows significant advantages in the field of multispectral imaging of transient targets. BACKGROUND

[0002] Multispectral imaging technology can reveal the composition distribution and dynamic changes in complex physical processes by acquiring imaging data of target objects at multiple spectral bands, and is widely used in physical, chemical, biological and industrial fields.

[0003] However, existing multispectral imaging technology has technical bottlenecks such as low spectral separation efficiency, difficulty in balancing time resolution and spatial resolution, etc. For example, traditional spectrometers based on diffraction principles can only analyze the spectrum of a single point and do not have spatial resolution, and are difficult to capture the dynamic evolution of transient processes; scanning imaging spectrometers have low time resolution due to the scanning process, making it difficult to meet the imaging needs of dynamic targets; diffraction imaging spectrometers cannot balance spatial resolution and spectral resolution; multispectral imaging methods based on filter switching cannot capture rapidly changing dynamic targets due to the need for mechanical filter switching; the light splitting efficiency of multispectral imaging methods based on aperture segmentation (sub-aperture) is affected by the number of imaging bands, and this light splitting method inevitably leads to significant attenuation of light intensity, thereby reducing light intensity utilization and possibly resulting in poor imaging quality in some bands. SUMMARY

[0004] To solve the problems existing in the prior art, the present application provides a multispectral synchronous imaging device and imaging method, which can realize multi-band, efficient and synchronous acquisition of target images, and has technical advantages such as high light intensity utilization, high time resolution and high spatial resolution.

[0005] In one aspect, the present application achieves the following technical solutions:

[0006] A multispectral synchronous imaging device, comprising:

[0007] A collimating light path for receiving target light and collimating it into an approximately collimated light beam;

[0008] A step-by-step light splitting part that uses a selective transmission and reflection light splitting method to step-by-step split the approximately collimated light beam output by the collimating light path into single-band light beams of multiple different target bands;

[0009] A reformatting light path for adjusting the light intensity, adjusting the direction and refocusing the multiple single-band light beams output by the step-by-step light splitting part;

[0010] and an imaging unit configured to receive the plurality of single-band light beams converged by the reformatting optical path and to complete synchronous acquisition of images of the plurality of single-band light beams.

[0011] In some embodiments, the collimating optical path comprises at least one long-focus collimating convex lens, and a focal length of the long-focus collimating convex lens is greater than or equal to a maximum optical path of the collimated light beam.

[0012] The maximum optical path is calculated from an exit light of the long-focus collimating convex lens as a starting point, through the step-by-step light splitting part, and to a focal point of the reformatting optical path as an ending point.

[0013] In some embodiments, the step-by-step light splitting part comprises at least two high-reflection narrow-band filters, and a range of transmission bands and reflection bands is selected according to actual application requirements.

[0014] The high-reflection narrow-band filters achieve high transmittance of target bands and high reflectance of non-target bands.

[0015] In some embodiments, the high-reflection narrow-band filters in the step-by-step light splitting part are sequentially arranged at a preset angle, so that the light beam reflected by the previous high-reflection narrow-band filter can accurately enter the next high-reflection narrow-band filter, forming a continuous band separation process.

[0016] In some embodiments, an included angle between a normal direction of an exit surface of the high-reflection narrow-band filter and a direction of the chief ray is an acute angle.

[0017] In some embodiments, the high-reflection narrow-band filters of the step-by-step light splitting part can adjust the angle according to the characteristics of the light source and experimental requirements, so that the transmission path and the reflection path of the light are both optimized.

[0018] In some embodiments, the reformatting optical path comprises at least one focusing convex lens for adjusting a spot size and a focusing position of the single-band light beam.

[0019] In some embodiments, the reformatting optical path further comprises a light intensity attenuation sheet for attenuating the single-band light beam with a light intensity greater than a threshold value.

[0020] In some embodiments, a photosensitive range of the imaging unit covers transmission bands of all high-reflection narrow-band filters in the step-by-step light splitting part.

[0021] On the other hand, the present application also proposes an imaging method based on the above-mentioned multispectral synchronous imaging device, comprising:

[0022] After the target light passes through the collimating optical path, an approximately collimated light beam with an included angle with the chief ray less than a threshold value is formed.

[0023] The approximate collimated light beam enters the step-by-step light splitting part, and is selectively transmitted and reflected in sequence to separate a plurality of single waveband light beams step by step;

[0024] The plurality of single waveband light beams enter the reformed optical path, and are subjected to light intensity adjustment, direction adjustment and refocusing, and finally converge on different imaging areas of the imaging unit;

[0025] The imaging unit synchronously collects images carrying different waveband information.

[0026] The multi-spectral synchronous imaging device and imaging method provided by the present application adopt high-reflective narrowband optical filters, and perform step-by-step waveband separation through selective transmission and reflection, thereby realizing high light intensity utilization rate and high spectral separation precision, and effectively avoiding the problems of light intensity loss and uneven waveband distribution caused by aperture segmentation in the conventional technology.

[0027] The multi-spectral synchronous imaging device and imaging method provided by the present application synchronously collect images of different wavebands through a single imaging unit, which can ensure the time consistency of images of different wavebands, and in combination with high-speed imaging technology, can realize high time resolution while ensuring high spatial resolution; in addition, all waveband imaging images are observed through a single optical path, thereby avoiding spatial differences and calibration errors caused by multi-optical-path imaging.

[0028] The multi-spectral synchronous imaging device and imaging method provided by the present application solve the overexposure problem caused by the light intensity difference of different wavebands through the light intensity attenuation sheet in the reformed optical path, and adapt to the multi-waveband imaging requirement under complex experimental conditions. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present application and constitute a part of the present application, do not limit the present application, and illustrate the embodiments of the present application. In the drawings:

[0030] Figure 1 The accompanying drawings, which are included to provide a further understanding of the embodiments of the present application and constitute a part of the present application, do not limit the present application, and illustrate the embodiments of the present application. In the drawings:

[0031] The accompanying drawings, which are included to provide a further understanding of the embodiments of the present application and constitute a part of the present application, do not limit the present application, and illustrate the embodiments of the present application. In the drawings:

[0032] 1 - target object, 11 - first light emitting area, 12 - second light emitting area, 13 - third light emitting area, 14 - fourth light emitting area, 2 - collimating light path, 21 - plano-concave lens, 22 - first mirror, 23 - long-focus plano-convex lens, 3 - stepwise light splitting part, 31 - second mirror, 32 - third mirror, 33 - fourth mirror, 301 - first high-reflective narrow-band filter, 302 - second high-reflective narrow-band filter, 303 - third high-reflective narrow-band filter, 304 - fourth high-reflective narrow-band filter, 4 - reformatting light path, 421 - fifth mirror, 422 - sixth mirror, 423 - seventh mirror, 424 - eighth mirror, 411 - first light intensity attenuation sheet, 412 - second light intensity attenuation sheet, 43 - plano-convex lens, 5 - imaging unit, 61 - first imaging image, 62 - second imaging image, 63 - third imaging image, 64 - fourth imaging image. DETAILED DESCRIPTION

[0033] Hereinafter, the term "include" or "may include" used in various embodiments of the present application indicates the existence of the invented function, operation, or element, and does not limit one or more functions, operations, or elements to be added. Also, as used in various embodiments of the present application, the terms "include", "have", and their conjugates merely indicate the presence of the mentioned features, numbers, steps, operations, elements, components, or combinations thereof, and should not be construed as excluding the possibility of the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.

[0034] In various embodiments of the present application, the expression "or" or "at least one of A or / and B" includes any combination of the listed terms or all the terms. For example, the expression "A or B" or "at least one of A or / and B" can include A, can include B, or can include both A and B.

[0035] The expressions (such as "first", "second", etc.) used in various embodiments of the present application can modify various constituent elements in various embodiments, but can not limit the corresponding constituent elements. For example, the above expressions do not limit the order and / or importance of the described elements. The above expressions are used only for the purpose of distinguishing one element from other elements. For example, the first user device and the second user device indicate different user devices, although both are user devices. For example, a first element can be called a second element, and likewise, a second element can be called a first element without departing from the scope of various embodiments of the present application.

[0036] It should be noted that if a description connects one component element to another component element, the first component element can be directly connected to the second component element, and a third component element can be connected between the first component element and the second component element. Conversely, when one component element is directly connected to another component element, it is understood that there is no third component element between the first component element and the second component element.

[0037] The terms used in the various embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the various embodiments of the present application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of the present application belong. The terms (such as those defined in a generally used dictionary) will be interpreted as having the same meaning as the contextual meaning in the relevant technical field and will not be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of the present application.

[0038] In order to make the purposes, technical solutions and advantages of the present application clearer, further detailed description of the present application is made below in combination with embodiments and drawings, the illustrative embodiments and their descriptions of the present application are only for the purpose of explaining the present application and not as a limitation of the present application.

[0039] Embodiment:

[0040] In view of the technical problems of low spectral separation efficiency and low light intensity utilization rate existing in the prior art multispectral imaging technology, the present embodiment proposes a multispectral synchronous imaging device. The device adopts a high-reflectivity narrow-band optical filter, realizes high light intensity utilization rate and high spectral separation precision through step-by-step light splitting, and effectively avoids the problems of light intensity loss and uneven wavelength distribution caused by aperture segmentation in the traditional technology.

[0041] As shown in Figure 1 The device proposed in the present embodiment includes, in sequence along the light path direction, a collimating light path 2, a step-by-step light splitting part 3, a reformatting light path 4 and an imaging unit 5.

[0042] The collimating light path 2 is used to collimate the incident light of each point of the target object 1 into an approximately collimated light beam with a divergence angle less than a threshold value and a diameter change less than a threshold value, which is suitable for subsequent spectral step-by-step separation and reformatting process.

[0043] Further, the collimating light path at least includes one long-focus collimating convex lens, and the focal length of the long-focus collimating convex lens is greater than or equal to the maximum optical path of the collimated light beam. The maximum optical path is calculated from the exit light of the long-focus collimating convex lens after collimation as the starting point, through the step-by-step light splitting part, and with the focal point of the reformatting light path as the end point.

[0044] Specifically, such as Figure 1 As shown, the collimating optical path 2 mainly includes a plano-concave lens 21, a first reflecting mirror 22, and a telephoto plano-convex lens 23 arranged sequentially along the optical path direction. The plano-concave lens 21 is used to change the viewing angle of the entire collimating optical path 2 lens group; the first reflecting mirror 22 is used to fold the incident light path of the telephoto plano-convex lens 23. The number and placement of the first reflecting mirrors 22 can be freely combined according to the needs of different usage scenarios, so as to minimize the overall length of the collimating optical path 2 while ensuring that the target object 1 is at the focal point of the telephoto plano-convex lens 23.

[0045] The step-by-step beam splitting section 3 is used to split an imaging beam into multiple imaging beams with different target wavelengths step by step.

[0046] Furthermore, the step-by-step beam splitting section 3 includes at least two highly reflective narrowband filters. Through selective transmission and reflection, it achieves multi-band separation of the aligned beam, retaining high light intensity utilization while avoiding light intensity loss in other bands during spectral separation.

[0047] Furthermore, when the collimated beam enters the high-reflectivity narrowband filter at an incident angle of θ, the transmitted wavelength passes through the filter, while the cutoff wavelength is reflected to the next filter, thus achieving multi-band separation step by step. The above transmission and reflection process is repeated to form multiple single-band beams of different wavelengths.

[0048] Furthermore, in the step-by-step beam splitting section 3, the cutoff depth of the high-reflectivity narrowband filter is greater than or equal to 4, and the incident angle θ is controlled to be no greater than 45°, ensuring high efficiency in transmittance and reflectance.

[0049] Furthermore, in the step-by-step beam splitting section 3, the angle of the high-reflectivity narrowband filter can be adjusted according to the characteristics of the light source and experimental requirements, so that both the transmission path and the reflection path of the light are optimized.

[0050] Specifically, such as Figure 1As shown, the step-by-step light splitting part 3 mainly includes a first high-reflection narrow-band filter 301, a second high-reflection narrow-band filter 302, a third high-reflection narrow-band filter 303, a fourth high-reflection narrow-band filter 304, a second mirror 31, a third mirror 32, and a fourth mirror 33. The working waveband of the four high-reflection narrow-band filters is 200-1200 nm, and the center wavelengths of the first high-reflection narrow-band filter 301, the second high-reflection narrow-band filter 302, the third high-reflection narrow-band filter 303, and the fourth high-reflection narrow-band filter 304 are 600 nm, 550 nm, 450 nm, and 500 nm, respectively, and the bandwidths are all ±1.5 nm. The first high-reflection narrow-band filter 301 transmits the light of the 600±1.5 nm waveband in the collimated light beam, reflects the light of the 200-598.5 nm and 601.5-1200 nm wavebands, the second mirror 31 adjusts the direction of the light reflected by the first high-reflection narrow-band filter 301, and the light is incident into the second high-reflection narrow-band filter 302 at the same incident angle. The second high-reflection narrow-band filter 302 transmits the light of the 550±1.5 nm waveband in the collimated light beam, reflects the light of the 200-548.5 nm, 551.5-598.5 nm, and 601.5-1200 nm wavebands, the third mirror 32 adjusts the direction of the light reflected by the second high-reflection narrow-band filter 302, and the light is incident into the third high-reflection narrow-band filter 303 at the same incident angle. In this way, after the transmission and reflection of the four filters, four imaging light beams with the wavebands of 600±1.5 nm, 550±1.5 nm, 450±1.5 nm, and 500±1.5 nm are obtained, and one imaging light beam containing the wavebands of 200-448.5 nm, 451.5-498.5 nm, 501.5-548.5 nm, 551.5-598.5 nm, and 601.5-1200 nm is obtained. In addition, the imaging light beam after the last filter can be processed again according to actual needs.

[0051] It should be noted that, Figure 1 The above description is only an exemplary illustration, and does not limit the number of high-reflection narrow-band filters and mirrors in the step-by-step light splitting part 3. The number of mirrors and the number of high-reflection narrow-band filters in the step-by-step light splitting part 3 can be increased or decreased according to needs.

[0052] The reformatting light path 4 re-focuses multiple single-waveband light beams on the same imaging surface by changing the propagation direction and spot position of each target waveband light beam.

[0053] Further, the reformatting optical path 4 at least includes a focusing convex lens for adjusting the spot size and focusing position of the single-band light beam. An optical intensity attenuation sheet can also be added in the reformatting optical path 4 to attenuate the over-bright waveband and avoid overexposure, thereby improving the imaging uniformity and data accuracy.

[0054] Specifically, as shown in Figure 1 The reformatting optical path 4 mainly includes a fifth mirror 421, a sixth mirror 422, a seventh mirror 423, an eighth mirror 424, a first optical intensity attenuation sheet 411, a second optical intensity attenuation sheet 412, and a plano-convex lens 43. The fifth mirror 421, the sixth mirror 422, the seventh mirror 423, and the eighth mirror 424 respectively change the directions of the four imaging light beams with wavebands of 500±1.5 nm, 450±1.5 nm, 550±1.5 nm, and 600±1.5 nm, and compact them. The two optical intensity attenuation sheets are used to reduce the brightness of the imaging light beams with relatively high intensity (in this embodiment, the imaging light beams with wavebands of 600±1.5 nm and 500±1.5 nm). The plano-convex lens 43 is used to focus the compacted four imaging light beams on the same imaging unit 5.

[0055] The imaging unit 5 is used to collect the imaging images of different wavebands on the same imaging surface.

[0056] Further, the photosensitive waveband range of the imaging unit 5 is designed and optimized according to the required wavebands to be collected.

[0057] Further, after collecting the imaging images of different wavebands, the imaging unit 5 can perform image intensity restoration processing in combination with the attenuation rate of the optical intensity attenuation sheet, thereby ensuring the true consistency of the collected data.

[0058] The embodiment also proposes an imaging method based on the above-described multi-spectral synchronous imaging device, which includes the following steps:

[0059] Step 1: The incident light of each point of the target object 1 forms an approximately collimated light beam with a small included angle with the main optical axis and a small diameter change through the collimating optical path 2.

[0060] Step 2: The collimated light beam enters the step-by-step light splitting part 3 and is separated into multiple single-band light beams through the transmission and reflection of the high-reflective narrow-band filter.

[0061] Step 3: The single-band light beam is adjusted in intensity, direction, and focused through the reformatting optical path 4, and forms closely arranged images in different imaging areas of the imaging unit 5.

[0062] Step 4: The imaging images of different wavebands are synchronously collected by the imaging unit 5, and the optical intensity restoration processing is performed on the imaging images of different wavebands in combination with the attenuation rate, thereby ensuring the data consistency.

[0063] The embodiment uses the above imaging device and imaging method to image the target object 1 shown in FIG. 1. The target object 1 has four light-emitting regions, i.e., a first light-emitting region 11, a second light-emitting region 12, a third light-emitting region 13, and a fourth light-emitting region 14, which respectively emit four kinds of light with wavelengths of 600±1.5 nm, 500±1.5 nm, 450±1.5 nm, and 550±1.5 nm. The light intensity of the light with wavelengths of 600±1.5 nm and 500±1.5 nm is relatively high. The imaging process is as follows. Figure 1

[0064] S1, the target object 1 is located on the focal plane of the collimating light path. The incident light from each light-emitting region of the target object 1 passes through the collimating light path 2 to form an approximately collimated light beam. The collimated light beam contains four kinds of light with wavelengths of 600±1.5 nm, 500±1.5 nm, 450±1.5 nm, and 550±1.5 nm.

[0065] S2, the formed collimated light beam enters the step-by-step light splitting part 3. First, the light with a wavelength of 600±1.5 nm in the light beam passes through the first high-reflectivity narrow-band filter 301. The other three kinds of light are reflected by the second mirror 31 and enter the second high-reflectivity narrow-band filter 302. The light with a wavelength of 550±1.5 nm in the light beam passes through the second high-reflectivity narrow-band filter 302. The other two kinds of light are reflected by the third mirror 32 and enter the third high-reflectivity narrow-band filter 303. The light with a wavelength of 450±1.5 nm in the light beam passes through the third high-reflectivity narrow-band filter 303. The last kind of light is reflected by the fourth mirror 33 and enters the fourth high-reflectivity narrow-band filter 304. The light with a wavelength of 500±1.5 nm in the light beam passes through the fourth high-reflectivity narrow-band filter 304. The imaging light beam of the target object 1 is divided into four imaging light beams with wavelengths of 600±1.5 nm, 500±1.5 nm, 450±1.5 nm, and 550±1.5 nm through the above process.

[0066] S3, the four imaging light beams with wavelengths of 600±1.5 nm, 500±1.5 nm, 450±1.5 nm, and 550±1.5 nm respectively enter the reformatting light path 4. The imaging light beams with wavelengths of 600±1.5 nm and 500±1.5 nm respectively pass through the second light intensity attenuation sheet 412 and the first light intensity attenuation sheet 411 to have light intensities similar to those of the light with wavelengths of 450±1.5 nm and 550±1.5 nm. After the four imaging light beams are changed in direction and compacted by the fifth mirror 421, the sixth mirror 422, the seventh mirror 423, and the eighth mirror 424, the imaging light beams are focused by the plano-convex lens 43 and imaged on the imaging unit 5.

[0067] ​S4, synchronously collect the imaging images of the four imaging beams of 600±1.5nm, 500±1.5nm, 450±1.5nm and 550±1.5nm by the imaging unit 5, which are respectively the first imaging image 61, the second imaging image 62, the third imaging image 63 and the fourth imaging image 64, and restore the original light intensity of the first imaging image 61 and the second imaging image 62 according to the attenuation rates of the first attenuation sheet 411 and the second attenuation sheet 412.

[0068] The multispectral synchronous imaging device provided in the embodiment can form a collimated light beam approximately parallel to the main optical axis through the collimated light path for the light rays of the target object. When the collimated light beam passes through the step-by-step light splitting part, the corresponding transmitted waveband light rays in the light beam can be transmitted and the cut-off waveband light rays in the light beam can be reflected into the next high-reflection narrowband filter. Finally, the collimated light beam can be divided into single-waveband light beams of different wavebands and a remaining light beam. The single-waveband light beams can pass through the light intensity adjustment, direction adjustment and refocusing of the reformatting light path. Finally, the imaging of the multiple single-waveband light beams can be closely arranged in a small range. Through a single imaging unit, the images of all wavebands can be collected, high-efficiency multispectral synchronous imaging can be realized, high temporal and spatial resolution, flexible design of collected wavebands and other advantages can be achieved, the problem that the temporal resolution and the spatial resolution are difficult to be considered in the existing multispectral imaging technology can be solved, the problems of low light intensity utilization and ghosting caused by the aperture segmentation method in the existing multispectral imaging technology can be avoided, and the multispectral imaging device is suitable for multispectral imaging with high temporal and spatial resolution, and has significant advantages in the application of multispectral synchronous imaging of transient targets.

[0069] The above detailed description is further detailed for the purpose, technical solutions and advantages of the present application. It should be understood that the above detailed description is only a specific embodiment of the present application and is not used to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A multispectral synchronous imaging device, characterized in that, include: A collimating optical path, wherein the collimating optical path is used to receive target light and collimate it into an approximately collimated beam; The step-by-step beam splitting section employs a selective transmission and reflection beam splitting method to gradually divide the approximately collimated beam output from the collimated optical path into multiple single-band beams with different target wavelengths. The optical path is refocused, which is used to adjust the intensity, direction and refocus the multiple single-band beams output by the step-by-step beam splitting section. And an imaging unit, which is used to receive multiple single-band beams converged through the re-normalized optical path and complete the synchronous acquisition of multiple single-band beam images. The step-by-step beam splitting section includes at least two high-reflectivity narrowband filters, and the range of transmission and reflection bands is selected according to actual application requirements; The high-reflectivity narrowband filter achieves high transmittance in the target band and high reflectance in non-target bands. The high-reflectivity narrowband filters in the step-by-step beam splitting section are arranged sequentially at preset angles, so that the light beam reflected by the previous high-reflectivity narrowband filter can accurately enter the next high-reflectivity narrowband filter, forming a continuous band separation process; the step-by-step beam splitting section uses a first reflecting mirror to readjust the direction of the light beam reflected by the previous high-reflectivity narrowband filter and shoot it into the next high-reflectivity narrowband filter at the same incident angle, where the incident angle refers to the angle at which the light beam enters the high-reflectivity narrowband filter; The reshaping optical path includes a second mirror that is configured in a one-to-one correspondence with at least two of the high-reflectivity narrowband filters, and each second mirror transforms the direction of the light beam transmitted by its corresponding high-reflectivity narrowband filter.

2. The multispectral synchronous imaging device of claim 1, wherein, The collimating optical path includes at least one long focal length collimating convex lens, the focal length of which is greater than or equal to the maximum optical path of the collimated beam; The maximum optical path is calculated starting from the outgoing light collimated by the long focal length collimating convex lens, passing through the progressively splitting beams, and ending at the focal point of the re-aligned optical path.

3. The multispectral imaging device of claim 1, wherein, The angle between the normal direction of the exit surface of the high-reflectivity narrowband filter and the direction of the principal optical axis is an acute angle.

4. The multispectral imaging device of claim 1, wherein, The high-reflectivity narrowband filter of the step-by-step beam splitting section can adjust its angle according to the characteristics of the light source and experimental requirements, so that both the transmission path and the reflection path of the light are optimized.

5. A multispectral simultaneous imaging device according to any one of claims 1-4, characterized in that, The reshaping optical path includes at least one focusing convex lens for adjusting the spot size and focusing position of a single-band beam.

6. The multispectral synchronous imaging device of claim 5, wherein, The re-normalized optical path is also equipped with an intensity attenuator to attenuate single-band beams with intensity greater than its threshold.

7. A multispectral simultaneous imaging device according to any one of claims 1-4, characterized in that, The light-sensing range of the imaging unit covers the transmission band of all high-reflectivity narrowband filters in the step-by-step beam splitting section.

8. An imaging method based on the multispectral synchronous imaging device according to any one of claims 1 to 7, characterized in that, include: After the target light ray is processed by the collimated optical path, it forms an approximately collimated beam with an angle to the principal optical axis that is less than its threshold value; The approximately collimated beam enters the step-by-step beam splitting section and undergoes selective transmission and reflection in sequence, separating multiple single-band beams step by step. Multiple single-band beams enter the re-normalized optical path, undergo intensity modulation, direction adjustment and refocusing, and finally converge in different imaging areas of the imaging unit; The imaging unit synchronously acquires images carrying information from different spectral bands.

Images