Rapid spectrum scanning liquid crystal electric control adjustable optical filter

Abstract

The invention provides a rapid spectrum scanning liquid crystal electric control adjustable optical filter which comprises a liquid crystal adjustable optical filter body and a drive controller. The liquid crystal adjustable optical filter body is of a multistage cascade structure, polarizing films, electric control liquid crystal wave plates and fixed phase retardation films are sequentially and mutually arrayed in parallel and are stacked at intervals to form multiple stages, and the fixed phase retardation films can be arranged or cannot be arranged in the first stage. The transmission polarized light directions of all the polarizing films are mutually in parallel, and an angle of 45 degrees is formed between the fast axis directions of all the electric control liquid crystal wave plates and the transmission polarized light directions of all the polarizing films. In the structure of each stage, the electric control liquid crystal wave plates are controlled by the drive controller, and alternating current overvoltage drive signals of different amplitudes are loaded. The liquid crystal electric control adjustable optical filter has the advantages that rapid spectrum scanning and imaging can be achieved, the spectrum scanning speed can be effectively increased, the spectral imaging frame frequency can be effectively improved, and the applied range of the liquid crystal electric control adjustable optical filter is greatly expanded in the fields of remote sensing detection, medical diagnosis, environmental monitoring, agricultural and forestry general investigation and the like.

Description

technical field [0001] The invention belongs to the technical field of spectral imaging, and in particular relates to a liquid crystal electronically controlled adjustable filter for spectral scanning. Background technique [0002] Compared with filter wheel, interference, dispersion, and acousto-optic tunable spectral imaging devices, spectral imaging devices based on liquid crystal electronically controlled tunable filters have the advantages of small size, light weight, and low power consumption. However, limited by factors such as driving mode and liquid crystal material, its spectral scanning speed is slow, and the spectral imaging frame rate is generally 10-20 frames per second. When the liquid crystal tunable filter has a large aperture, the Conventional drive mode, the response time can generally reach hundreds of milliseconds. For dynamic spectral imaging, the time for spectral imaging system to obtain spectral information is largely restricted, which brings great ...

AI Technical Summary

Problems solved by technology

[0003] At present, the response time of spectral imaging equipment provided by CRI in the United States is generally 50ms-150ms, and the imaging frame rate is 7-20 frames per second. During spectral scanning imaging, the slow spectral scanning speed will lead to blurred spectral images and inaccurate spectral data extraction, which will affect the results of spectral identification and seriously affect the application of spectral imaging equipment based on liquid crystal electronically controlled adjustable filters in remote sensing detection, medical diagnosis, Applications in environmental protection monitoring, agricultural and forestry censuses and other fields

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