Microscopic hyperspectral system test LED light source analysis

The microscopic hyperspectral system is a new application method combining hyperspectral cameras, microscopes, computers, etc. With the help of the microscopic structure of the microscope structure to further improve the microscopic scale of the sample to be tested under different magnifications, it can fully observe the substance in its microscopic scale. In this way, the spectral information of the substance can be further obtained, so as to make full use of the advantages of hyperspectral in spectroscopy and image, combined with the microscopic mechanism system, to further expand the application of hyperspectral technology.

1. Test principle and method

Hyperspectral imaging technology is an image data technology based on a very large number of narrow bands developed in the past two decades. Its prominent application is in the field of remote sensing detection, and it has greater application prospects in more and more civilian fields. It concentrates advanced technologies in the fields of optics, optoelectronics, electronics, information processing, and computer science. It is an emerging technology that combines traditional two-dimensional imaging technology and spectroscopy technology.

The definition of hyperspectral imaging technology is based on multi-spectral imaging, in the spectral range from ultraviolet to near-infrared (200-2500nm), using imaging spectrometer, in the spectral coverage of tens or hundreds of spectral bands Continuous imaging of the target object. While obtaining the spatial feature imaging of the object, the spectral information of the measured object is also obtained.

Target object-imaging objective lens-entrance slit-collimating lens-PGP-focusing lens-CCD prism-grating-prism: PGP

Figure 1 Imaging principle diagram

The spectral resolution of the spectrometer is determined by the width of the slit and the linear dispersion produced by the optical spectrometer. The spectral resolution is determined by the imaging performance of the optical system (point spread size).

The imaging process is: after each image on a line (X direction), in the process of the detection system conveyor belt, the arrayed detectors sweep out a strip-shaped track to complete the longitudinal scan (Y direction). The three-dimensional hyperspectral image data of the sample can be obtained by integrating the horizontal and vertical scanning information.

Figure 2 Like a cube

Two, test analysis

Red light sample test:

Test conditions: current: 220mA voltage: 1.89V

Camera parameters: 1392x520 (spatial dimension x spectral dimension) Exposure time: 0.1ms Spectral range: 400-1000nm

Spectral resolution: 3.6nm Spectral calibration file reference attachment

Microscope: Magnification: 10X objective lens

The distance between the surface of the sample and the surface of the objective lens: 1.6cm

Imaging mode: reflection imaging mode

Spectral range of microscope light source: 350nm-2500nm

The following figure shows the Red (red) LED hyperspectral image information and spectral information taken by the microscopic hyperspectral system. The part looks a little blurry, which is caused by the uneven surface of the sample under a high magnification objective lens. The clearer part of the image is the state where the camera and the microscope system are in focus, and some blurred areas are slightly off. Focus position. In the figure below, multiple clearer images with different focus positions are listed.

Figure Mobile phone to take photos of microscope eyepieces

Figure 3 Characteristic spectrum of Red LED light source

Figure 4 Grayscale image of Red LED light source at 662.8nm

Blue blue sample test:

Test conditions: current: 200mA voltage: 3V

Camera parameters: 1392x520 (spatial dimension x spectral dimension) Exposure time: 0.05ms

Spectral range: 400-1000nm Spectral resolution: 3.6nm Spectral calibration file reference attachment

Microscope: Magnification: 10X objective lens

The distance between the surface of the sample and the surface of the objective lens: 1.4cm

Imaging mode: reflection imaging mode

Spectral range of microscope light source: 350nm-2500nm

The following figure shows the blue (blue) LED hyperspectral image information and spectral information taken by the microscopic hyperspectral system. The part looks a little blurry, which is caused by the uneven surface of the sample under a high magnification objective lens. The clearer part of the image is the state where the camera and the microscope system are in focus, and some blurred areas are slightly off. Focus position. In the figure below, multiple clearer images with different focus positions are listed.

Figure Mobile phone to take photos of microscope eyepieces

Figure 5 The characteristic spectrum of the Blue LED light source

Figure 6 Grayscale image of Blue LED light source at 444.9nm

Figure 7 Grayscale image of Blue LED light source at 444.9nm

Three, summary

The microscopic structure of the LED light source can be observed under a 10X objective lens with a microscopic hyperspectral system, and the characteristic wavelengths corresponding to different LED light sources can be accurately tested, and the image is also very clear (the sample is not completely flat in the actual test ), through the focus adjustment, some characteristic information of the light source itself can be highlighted.