CN214011030U - Multi-mode microscopic hyperspectral imager - Google Patents

Abstract

The utility model discloses a multi-mode microscopic hyperspectral imager, which comprises an illumination module and a hyperspectral detection module; the illumination light source and the detection module are integrated to be coaxial by applying two illumination modes of the epi-illumination and the transmission illumination, so that the illumination uniformity in a view field range is ensured. By switching the illumination mode and replacing different types of light sources, the multimode microscopic hyperspectral imager can realize three working modes of reflection imaging, transmission imaging and fluorescence detection, and can perform multimode hyperspectral imaging and detection on samples with different characteristics, such as non-transparent samples, semitransparent/transparent samples and fluorescence samples.

Description

Multi-mode microscopic hyperspectral imager

Technical Field

The utility model relates to a micro-hyperspectral imager of multi-mode (reflection imaging, transmission imaging, fluorescence detection).

Background

The hyperspectral imaging technology can acquire a hyperspectral cubic data set, and simultaneously contains two-dimensional image information and one-dimensional spectral information of a sample to be detected, so that the hyperspectral imaging technology is widely applied to the scenes of environment in-situ monitoring, food safety detection, authenticity judgment and the like. When the hyperspectral imaging technology is used for microscopic detection, due to the extremely short working distance (submillimeter level) of the high-power microscope objective, shadow can appear on the lower surface of the microscope objective caused by traditional external light source illumination, so that uniform illumination of the surface to be detected can not be realized, and the signal-to-noise ratio and the accuracy rate of sample imaging and spectral detection can be greatly influenced. In addition, most of commercial hyperspectral imagers can only work in a single detection mode, and multimode detection of samples with different characteristics is difficult to realize.

The utility model discloses a system performance weak point that hyperspectral imaging probably exists under the microscopic detection is considered, a micro-hyperspectral imager of multi-mode is proposed. Through designing two kinds of lighting methods of formula illumination of falling and transmission-type illumination, it is coaxial with the detection light path to integrate the light source, guarantees the sample plane uniform lighting that awaits measuring, effectively avoids the shadow scheduling problem that external light source brought. In addition, only the lighting module needs to be switched, and the system can realize reflective imaging, transmission imaging and fluorescence detection, and realize multi-mode detection of samples with different characteristics. The system has simple structure and low cost, and is expected to be used in the measurement fields of in-situ microorganism detection, industrial sample microstructure detection and the like.

Disclosure of Invention

Under the circumstances is surveyed in order to overcome the micro-high spectrum, the shadow that external light source appears at objective focal plane and illumination inhomogeneous probably are caused to high magnification micro objective's short working distance to and current commercial high spectral imager detection mode single scheduling problem, the utility model aims at providing a micro-high spectral imager of multi-mode.

A multi-mode microscopic hyperspectral imager comprises an illumination module and a hyperspectral detection module;

the lighting module comprises: the device comprises a broadband light source used for observing the absorption characteristics of a sample, a blue-violet light source for exciting the characteristic fluorescence of the sample, a single-mode optical fiber for coupling the light source, a collimator of a collimation light source, a long-focus lens for converging collimated light, a semi-transparent semi-reflecting mirror for turning a light path and a microscope objective for collimating uniformly. The illumination module integrates a light source to be coaxial with the detection module, so that the surface of the sample to be detected is uniformly illuminated;

the hyperspectral detection module comprises: the device comprises a microscope objective for collecting emergent signals on the surface of a sample, a long-pass filter for filtering exciting light/stray light, an imaging lens for imaging, a slit for selecting a line region, a converging lens for collimating divergent light, a prism grating pair for splitting light, a tube lens for converging a dispersion signal and a CMOS camera for imaging. The hyperspectral detection module is used for capturing two-dimensional image information and one-dimensional spectral information of a sample to be detected and realizing hyperspectral imaging.

For the epi-illumination, a light source emits broadband light or blue-violet laser, the broadband light or the blue-violet laser is coupled to a collimator through a single-mode fiber to form a collimated light spot, the collimated light spot is converged through a long-focus lens, meanwhile, the collimated light spot passes through a light path turned by a semi-transparent semi-reflecting mirror and finally converged into a point on a back focal plane of a microscope objective, and the point can be understood as a point light source; the point light source emitted from the rear focus of the microscope objective is collimated into parallel light after passing through the microscope objective and is uniformly incident to a sample to be measured, so that uniform illumination in a field range is realized, and the occurrence of shadows can be effectively avoided;

on the other hand, the illuminated sample is also positioned on the focal plane of the microscope objective, the scattered light emitted from the focal plane is captured by the same microscope objective and converged into parallel light which enters the hyperspectral detection module through the half-mirror and the long-pass filter, and the long-pass filter is used for filtering the excitation light and part of the stray light; the light signal is firstly converged on the slit through the imaging lens, the slit plays a role in selecting a scanning line area, and light outside the slit is filtered; the optical signal is emitted to a convergent lens after being selected by the slit, and is incident to a subsequent prism grating pair structure in parallel after being converged. The three optical elements of the first prism, the grating and the second prism act together to realize the light splitting of the captured signal; the dispersed multiband optical signals are converged on a CMOS camera through a tube lens, and finally the image surface of the camera contains broadened spectral information and spatial information of a corresponding line area selected by a slit. Under the condition of epi-illumination, the multi-mode microscopic hyperspectral imager can realize reflective detection of a non-transparent sample and fluorescence detection of a fluorescent sample.

For transmission type illumination, broadband light emitted by the light source is coupled to the collimator through the single-mode optical fiber to form a collimated light spot, the collimated light spot is directly incident to a sample to be detected from the lower part of the sample, and the transmitted light is captured by the hyperspectral detection module in the same signal acquisition mode. Under the condition of transmission type illumination, the multi-mode microscopic hyperspectral imager can realize transmission type detection of transparent/semitransparent samples.

The displacement platform loaded with the sample to be detected can uniformly move step by step along the direction vertical to the slit until the whole plane of the sample to be detected is covered, and the line scanning process of the line area selected by the slit is realized. If the displacement platform has a two-dimensional scanning function, the multi-mode microscopic hyperspectral imager has the potential of realizing the large-scale measurement of a sample to be measured with a larger scale.

The utility model has the advantages that:

the utility model provides a two kinds of lighting methods of formula illumination and transmission-type illumination have realized that the illumination light is in coaxially with high spectral detection, guarantee the even illumination of the sample that awaits measuring in the survey line region, have effectively avoided the shadow that traditional high spectral imager external light source probably appears in microscopic detection and the inhomogeneous scheduling problem of illumination. In addition, the system can realize different mode detection of samples with different characteristics by replacing the light source and the illumination mode, and the defect of single detection mode of the commercial hyperspectral imager is overcome. Microscopic detection can guarantee high spatial resolution, the utility model discloses be expected to be applied to measurement fields such as normal position microbial detection, industrial sample micro-structure detection.

Drawings

FIG. 1 is a schematic diagram of a multi-mode microscopic hyperspectral imager in the patent of the present invention;

the lighting module comprises: the device comprises a single-mode fiber (1) directly connected with a light source, a collimator (2), a long-focus lens (3) and a half-transmitting and half-reflecting mirror (4); the hyperspectral detection module comprises: the device comprises a long-pass filter (5), a microscope objective (6), a displacement platform (7), an imaging lens (8), a slit (9), a converging lens (10), a first prism (11), a grating (12), a second prism (13), a tube lens (14) and a CMOS camera (15).

Detailed Description

The present invention will be further explained with reference to the accompanying drawings.

As shown in fig. 1, for epi-illumination, a broadband light source/blue-violet light source emits laser, which is coupled to a collimator 2 through a single-mode fiber 1 to become a collimated light spot, and the collimated light spot is converged by a long-focus lens 3 with a focal length of 75mm, and is simultaneously deflected by a half-mirror 4 to form a light path, and finally converged into a point on a back focal plane of a microscope objective 6, and the point can be understood as a point light source; the point light source emitted from the rear focus of the microscope objective 6 is collimated into parallel light after passing through the microscope objective 6, and the parallel light is uniformly incident to a sample to be measured loaded on the displacement platform 7, so that uniform illumination in a field range is realized, and the occurrence of shadows is effectively avoided.

On the other hand, the illuminated sample is also positioned on the focal plane of the microscope objective 6, and the scattered light/fluorescence emitted from the sample at the focal plane is captured by the same microscope objective 6 and converged into parallel light which enters the hyperspectral detection module through the half-mirror 4 and the long-pass filter 5 with the wavelength of 450 nm; firstly, the light signal passes through an imaging lens 8 with a focal length of 50mm and is converged on a slit 9 with a slit width of 10 mu m, the slit 9 plays a role of scanning line area selection, the light signal is emitted to a converging lens 10 with a focal length of 50mm after passing through the slit 9, and the light signal is incident in parallel to a subsequent prism grating pair structure after being converged. The first prism 11 with the wedge angle of 10 degrees, the grating 12 with the grating line logarithm of 300lp/mm and the second prism 13 with the wedge angle of 10 degrees jointly act to realize the light splitting of the captured signal; the dispersed multiband optical signal is converged on a CMOS camera 15 through a tube lens 14 with a focal length of 50mm, and finally the camera phase plane contains broadened spectral information and spatial information of a corresponding line area selected by a slit. Under the condition of epi-illumination, the multi-mode microscopic hyperspectral imager can realize reflective detection of a non-transparent sample and fluorescence detection of a fluorescent sample.

For transmission type illumination, light emitted by a broadband light source is coupled to a collimator 2 through a single-mode fiber 1 to form collimated light spots, the collimated light spots are directly incident to a sample to be detected from the lower part of the sample, and the transmitted light is captured by a hyperspectral detection module in the same signal acquisition mode. Under the condition of transmission type illumination, the multi-mode microscopic hyperspectral imager can realize transmission type detection of transparent/semitransparent samples.

The displacement platform 7 loaded with the sample to be detected can uniformly move step by step along the direction vertical to the slit 9 until the whole plane of the sample to be detected is covered, and the line scanning process of the line area selected by the slit 9 is realized. If the displacement platform has a two-dimensional scanning function, the multi-mode microscopic hyperspectral imager has the potential of realizing the large-scale measurement of a sample to be measured with a larger scale.

In the embodiment of the utility model, the illumination light source and the hyperspectral detection module are integrated to be coaxial, so that the whole plane to be detected is illuminated uniformly without possible shadows; therefore, the microscope objective 6 with different multiplying powers can be replaced to meet the requirements of different view field sizes and spatial resolutions. Greatly increased the utility model discloses a wide applicability.

As the utility model discloses an extension, the micro-high spectral imager of multi-mode of this set of vertical structure can the horizontal structure build on optical platform equally, and this set of system is applicable to the micro-high spectral detection of multi-mode equally.

The embodiments in the above description can be further combined or replaced, and the embodiments are only described in the preferred embodiments of the present invention, and are not limited to the concept and scope of the present invention, and various changes and modifications made by the technical solutions of the present invention by those skilled in the art without departing from the patent design idea of the present invention all belong to the protection scope of the present invention. The scope of the invention is given by the appended claims and any equivalents thereof.

Claims (5)

1. A multi-mode microscopic hyperspectral imager is characterized in that: the hyperspectral imager comprises an illumination module and a hyperspectral detection module; the illumination module integrates a light source to be coaxial with the detection module by using two illumination modes of an epi-illumination mode and a transmission illumination mode; the hyperspectral detection module is positioned in the direction vertical to the sample and is used for capturing inelastic scattering signals of the sample to be detected at the focal plane, collecting two-dimensional image information and one-dimensional spectrum information and realizing microscopic hyperspectral imaging; by combining with the scanning motion of the displacement platform and simultaneously changing the type and the illumination mode of the illumination light source, the push-broom type multi-mode microscopic hyperspectral detection can be realized on a large-scale sample.

2. The multi-mode microscopic hyperspectral imager of claim 1, wherein: the lighting module comprises: the device comprises a single-mode fiber (1) directly connected with a light source, a collimator (2), a long-focus lens (3) and a half-transmitting and half-reflecting mirror (4); the hyperspectral detection module comprises: the device comprises a long-pass filter (5), a microscope objective (6), a displacement platform (7), an imaging lens (8), a slit (9), a convergent lens (10), a first prism (11), a grating (12), a second prism (13), a tube lens (14) and a CMOS camera (15); the illumination module is used for integrating illumination light to be coaxial with the detection module and generating uniform illumination light on the surface of the sample to be detected; the hyperspectral detection module is used for collecting inelastic scattering signals sent out by the surface of a sample to realize hyperspectral detection; the epi-illumination is as follows: the illuminating light is emitted downwards from the upper part of the sample, vertically irradiates on the sample, and the reflected light is collected; the transmission type illumination comprises the following steps: the illuminating light is emitted upwards from the lower part of the sample, vertically irradiates on the sample, and the transmitted light is collected.

3. The multi-mode microscopic hyperspectral imager of claim 1, wherein: the implementation manner of the epi-illumination is as follows: the light source is coupled into the collimator (2) through the single-mode fiber (1), parallelly emits to the long-focus lens (3), and simultaneously turns a light path through the semi-transparent semi-reflecting mirror (4) to finally converge on a back focal plane of the microscope objective (6); the converged light spot can be equivalent to a point light source positioned at the back focus of the microscope objective (6), and is collimated into parallel light by the microscope objective (6) after being emitted out, and the parallel light is uniformly emitted out to the surface of a sample to be measured; the transmission type illumination implementation mode is as follows: the light source is coupled into the collimator (2) through the single-mode fiber (1), and collimated light is directly and uniformly emitted and penetrates through a sample to be detected; the hyperspectral detection module comprises: a sample on a displacement platform (7) positioned at the focal plane of the microscope objective (6) emits a scattered light signal, the scattered light signal is captured by the microscope objective (6), collimated into parallel light and emitted backwards, the parallel light passes through the half-mirror (4) and the long-pass filter (5), is incident on the imaging lens (8) and is converged to the slit (9), and the slit (9) plays a role in scanning line area selection; the light emitted from the slit (9) is collimated into parallel light again by the convergent lens (10) and is incident on the prism grating pair structure; the prism grating pair structure comprises a first prism (11), a grating (12) and a second prism (13) and plays a role in splitting polychromatic light; the light dispersed by the prism grating pair finally converges on a CMOS camera (15) through a tube lens (14), and the polychromatic light can be seen on the camera to spread along a certain direction and simultaneously contain the spatial information of the sample in the measuring line area.

4. The multi-mode microscopic hyperspectral imager of claim 1, wherein: under the condition of the epi-illumination, a broadband light source is adopted, and a system can measure a reflection signal of a non-transparent sample; under the condition of epi-illumination, a blue-violet light source is adopted, and the system can measure the fluorescence signal of the fluorescence sample; in the case of transmission illumination, the system is capable of measuring the transmission signal of a transparent/translucent sample using a broadband light source.

5. The multi-mode microscopic hyperspectral imager of claim 1, wherein: the displacement platform (7) loaded with the sample to be detected can control the sample to uniformly move step by step along the direction vertical to the slit (9) until the whole plane of the sample to be detected is covered, and the line scanning process of the line area selected by the slit (9) is realized.

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