Optical spectrum imaging device based on fresnel diffraction microlens array

Abstract

The invention discloses a spectral imaging device based on a Fresnel diffraction microlens array. The device comprises a hermetical optical channel composed of a microlens substrate, a detector substrate and a support side block, wherein, the microlens substrate and the detector substrate are respectively arranged from the top down and in parallel; the lower surface of the microlens substrate is provided with the processed microlens array composed of N Fresnel diffraction microlens, and the upper surface of the detector substrate is provided with a detector array composed of N detectors, the detector array corresponds to the microlens array; focal points of the N Fresnel diffraction microlens on the microlens array are respectively superposed with photosurfaces of the N detectors on the detector array on a one-to-one basis; each microlens is provided with the same converging focal length f0 and level number L, but different convergence center wavelengths lambda0 correspond to absorption wavelengths of N detection ingredients respectively, and at that time, a radius rm of each endless belt of an FZP needs to satisfy formula (1), wherein, m equals 1, 2, ..., M; the focal length f0 and the resolution delta lambda satisfy formula (2), and the microlenses take a converging action on the light with the wavelengths in a range of the lambda0 plus / minus delta lambda. The device adopts a multichannel array manner, simultaneously obtains a plurality of absorption spectra of a plurality of gas or substance ingredients, and has the advantages of small size, light weight, easy batch production, low cost and the like.

Description

technical field [0001] The invention belongs to the technical field of spectral imaging, and in particular relates to a spectral imaging system for multi-channel spectral analysis and detection of gas / liquid components and concentrations. Background technique [0002] Spectral technology is a common method of material analysis, widely used in metallurgy, geology, petrochemical, medical and health and environmental protection and other fields, especially gas / liquid analysis and detection, spectral analysis based on the principle of infrared absorption can detect the type or concentration of gas Efficient and sensitive detection. The traditional spectrum analysis instrument adopts continuous spectrum measurement, which has a wide measurement range and high precision, but it is bulky, expensive and not easy to carry. With the development of MEMS, binary optics and integrated optics technology, the miniaturization and miniaturization of spectrometers become possible. The micro...

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Problems solved by technology

This design can obtain higher optical resolution, and the use of scanning micromirrors can reduce the volume of the spectroscopic system, but the scanning spectroscopic system has disadvantages such as poor stability and slow detection speed.

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