Microscopic hyperspectral system test LED light source analysis report

The micro-hyperspectral system is a new application method combining hyperspectral camera, microscope, computer, etc., and the microscopic scale of the sample to be tested can be further improved by the microscope structure at different magnifications, and the substance can be fully observed on the microscopic scale. The image information, in order to further obtain the spectral information of the material, thus taking full advantage of the advantages of hyperspectral in the spectrum and image, combined with the micro-mechanism system, further expands the application of hyperspectral technology.

First, the test principle and method

Hyperspectral imaging technology is a very narrow-band image data technology developed in the past two decades. Its most prominent application is in the field of remote sensing detection, and it has a greater application prospect in more and more civilian fields. It integrates 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 with spectral technology.

Hyperspectral imaging is defined as the use of imaging spectrometers in the spectral range of tens or hundreds of spectral bands in the spectral range from ultraviolet to near-infrared (200-2500 nm) over multispectral imaging. The target object is continuously imaged. At the same time as obtaining the spatial feature of the object, the spectral information of the measured object is also obtained.

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

Figure 1 Imaging schematic

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

The imaging process is: each time a line on the line (X direction), during the process of detecting the conveyor belt advancement, the arranged detectors sweep out a strip track to complete the longitudinal scan (Y direction). The three-dimensional hyperspectral image data of the sample can be obtained by combining the horizontal and vertical scanning information.

Figure 2 like a cube

Second, test analysis

Red red LED 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

Distance between the surface of the sample and the surface of the objective lens: 1.6cm

Imaging mode: reflection imaging mode

Microscope source spectrum range: 350nm-2500nm

The following illustration is a red (red) LED hyperspectral image information and spectral information taken using a microscopic hyperspectral system. The part seems a bit fuzzy, which is caused by the uneven surface of the sample under the high magnification objective lens. The sharper part of the image is the state where the camera and the microscope system are in focus, and some blurred areas are slightly deviated. Focus position, a clear picture of multiple different focus positions is listed in the figure below.

Figure mobile phone taking microscope eyepiece photo

Figure 3 Characteristic spectrum of the Red LED source

Figure 4 Red LED light source at 662.8nm grayscale image

Blue Blu-ray LED 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

Distance between the surface of the sample and the surface of the objective lens: 1.4cm

Imaging mode: reflection imaging mode

Microscope source spectrum range: 350nm-2500nm

The following illustration is a blue (blue) LED hyperspectral image information and spectral information taken using a microscopic hyperspectral system. The part seems a bit fuzzy, which is caused by the uneven surface of the sample under the high magnification objective lens. The sharper part of the image is the state where the camera and the microscope system are in focus, and some blurred areas are slightly deviated. Focus position, a clear picture of multiple different focus positions is listed in the figure below.

Figure mobile phone taking microscope eyepiece photo

Figure 5 Characteristic spectrum of the Blue LED source

Figure 6 Blue LED light source at 444.9nm grayscale image

Figure 7 Blue LED light source at 444.9nm grayscale image

Third, summary

The microscopic hyperspectral system can observe the microscopic structure of the LED light source under the objective lens of 10X times, and can accurately test the characteristic wavelengths corresponding to different LED light sources, and the image is also very clear (the sample is not completely flat during the actual test). ), through the focus adjustment, it can highlight some characteristic information of the light source itself.