Third level Fabry-Perot cavity type tunable ray filter system

Abstract

The invention discloses a third level Fabry-Perot cavity type tunable ray filter system, comprising two structures. The first structure comprises three Fabry-Perot cavities, wherein, the Fabry-Perot cavities are electrically tunable; the second structure comprises a polarizer, the three Fabry-Perot cavities and an analyzer, wherein, the Fabry-Perot cavities have the tunable effect only on the linearly polarized light which goes through the polarizer. The invention realizes continuously adjustable narrowband light-filtering within the wide spectral range by the reasonable design of the three Fabry-Perot cavities, the Fabry-Perot cavities have mature fabrication process, and the implementation of the whole system is convenient. The invention further has the characteristics of large aperture, simple assembling, wide light-filtering spectrum range and high spectral resolution, and can be applied in the fields of remote sensing, biomedicine, astronomical observation and the like.

Description

technical field [0001] The invention relates to an optical tunable filter device, in particular to a three-stage Fabry-Perot cavity tunable filter system, which can be applied to the field of spectral imaging. Background technique [0002] Tunable filter systems include mechanical tuning, acousto-optic tuning, electro-optic tuning filter systems, etc. [0003] Mechanically tunable filters are mainly used in interference filter systems and polarization interference filter systems. By changing the physical parameters of the devices in the system, such as thickness, angle, etc., the purpose of tuning the spectral characteristics of the filter system is achieved. The mechanical tuning filter system generally has a moving mechanism, poor stability and firmness, slow tuning response speed, and complex structure. [0004] The acousto-optic tunable filter is mainly a tunable filter system made by using the abnormal Bragg diffraction effect of anisotropic crystals under the acousto-...

AI Technical Summary

Problems solved by technology

[0006] Lyot-type and Solc-type tunable filters usually require multi-stage stacking to have a better filtering effect. The higher the spectral resolution requirement, the more stacking stages are required, which leads to complex system structure, larger volume, Contradictions such as lower transmittance; Fabry-Perot cavity is currently mainly used in optical communication wavelengths, free spectral region and tuning ability are not required

In the field of optical communication, there is a superposition of two Fabry-Perot cavities with slightly different free spectral regions to form a vernier cascaded FP filter, but it can only realize dynamic filtering and selection of multiple frequencies, not continuous filtering

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