Liquid crystal tunable filter based static full stokes imaging spectropolarimeter

Abstract

The invention relates to a liquid crystal tunable filter based static full stokes imaging spectropolarimeter. The imaging spectropolarimeter comprises a front optical system, a collimating lens, a liquid crystal tunable filter and a phase modulation module, wherein the liquid crystal tunable filter is positioned in the same optical axis as the front optical system and the collimating lens; and the phase modulation module is arranged between the collimating lens and the liquid crystal tunable filter and is positioned in the same optical axis as the collimating lens and the liquid crystal tunable filter. The liquid crystal tunable filter based static full stokes imaging spectropolarimeter provided by the invention has the advantages of no moving part, static measurement, full stokes polarization-state measurement, high spatial resolution, simple structure and high stability.

Description

technical field [0001] The invention belongs to the field of optics, and relates to an imaging spectral polarization instrument, in particular to a static full-Stokes imaging light polarimeter based on a liquid crystal tunable filter. Background technique [0002] Imaging Spectropolarimetry (Imaging Spectropolarimetry) technology is an optical information acquisition technology that can obtain target images and obtain spectral polarization information of each pixel in the image. Imaging Spectropolarimetry can simultaneously obtain target images, spectra and Polarization information has important application value in industry, agriculture, remote sensing and military affairs, and is one of the frontier research topics in the world. [0003] In general, a two-dimensional focal plane detector can only obtain two-dimensional information in one exposure. To obtain the image, spectrum and polarization information of the target, it must go through some form of mechanical scanning o...

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Problems solved by technology

Computational tomography spectropolarimeter designed by Eustace L.Dereniak et al. [Eustace L.Dereniak, Nathan A.Hagen, William R.Johnson, et.al. "Imaging Spectropolarimetry". Proceedings of SPIE Vol.5074, 272~285( 2003)] can obtain the spatial, spectral and full Stokes polarization information of the target in one exposure, but due to the influence of the calculated holographic grating diffraction angle and the size of the focal plane array detector, the spectral resolution and spatial resolution are limited , and there is a principled "lost cone" phenomenon

Japanese scholar Kevin W.Peters proposed an imaging spectropolarimeter that adds a liquid crystal tunable phase retarder to the collimated optical path of a spatially modulated imaging spectrometer [Kevin W.Peters, Theodore S.Turner, Jr.et.al. "Portable visible imaging spectropolarimeter for remote sensing applications". SPIE Vol.3498, 223-230 (1998)] can obtain the full Stokes spectrum polarization information of the target, but it needs to scan the same target multiple times to complete the imaging. come very difficult

The imaging spectropolarimeter based on the liquid crystal tunable filter proposed by the National Aerospace Laboratory of Japan requires a stepping motor to drive the liquid crystal tunable optical plate to rotate when obtaining the polarization information of the target. Due to the moving parts, the stability is reduced. , at the same time, it can only measure the linear polarization state, but cannot complete the measurement of the full Stokes polarization state

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