High flux, high detection sensitivity minitype polarization interference imaging spectrometer

Abstract

The invention relates to a high-sensitivity remote sensing image spectrometer which can obtain target image, interference spectrum and polarization information, composed of a polarization interferometer, an image lens and an area detector which are coaxially arranged along incident light. The polarization interferometer is composed of a polarizer, Sawa polariscope and a checker, wherein the Sawa polariscope comprises two natural uniaxle negative crystal Sawa plates in same thickness, vertical optical axis, and corner as 45 degrees with the system optical axis, the polarizer and the checker are both composed of two wedge natural uniaxle negative crystal GeLanTaLe lens with an air space. The signal output of the detector is connected with an external computer signal processing system. Compared with prior art, the invention eliminates an advanced optical system and a slit of traditional device, while the invention uses the Sawa polariscope made from natural crystal as a horizontal shearing beam splitter, with simple structure, small volume, high flux, high signal / noise ratio, high detection sensitivity, high resolution, wide spectrum, and strong detecting ability on remote target and weak signal.

Description

technical field [0001] The invention belongs to the technical field of optical image processing instruments, and relates to a remote sensing interference imaging spectrometer that can be used to simultaneously acquire target two-dimensional image, one-dimensional spectrum and polarization information. Background technique [0002] Imagers, spectrometers, and polarimeters in common concepts belong to three different classes of optical instruments. The shape and shadow image of the target can be obtained by using the imaging instrument, that is, the two-dimensional spatial information of the target; the spectrum of the target can be obtained by using the spectrometer to obtain the structure and chemical composition of the substance; the polarization information of the target can be obtained by using the polarimeter to obtain the object’s Attributes. Historically, these three categories of instruments developed independently. In the late 1980s, an interferometric imaging spec...

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Problems solved by technology

However, the main disadvantage of the spatially modulated imaging spectrometer is that the device contains a slit determined by the spatial resolution, which has nothing to do with the spectral resolution, so that the energy entering the system is greatly limited.

In addition, since most of these imaging spectrometers are based on Sagnac interferometers, there are more oblique light, larger volume, and after multiple reflections and refractions, the energy loss is large

In 1996, the University of Washington developed the Digital Array Scanning Interferometry Spectrometer (DASI), which is a spatially modulated polarization interference imaging spectrometer. The imaging spectrometer uses a Wollaston prism, angle shearing, and short-range targets. Because the instrument contains slits determined by the spatial resolution, the energy utilization rate is too low, and the ability to detect long-distance targets and weak signals is poor; on the other hand, its far-field fringes are hyperbolic, which is not conducive to spectral restoration and image synthesis

However, due to the use of two polarizers as polarizers and analyzers (analyzers) in the polarization interferometer of the device, there are disadvantages such as low degree of polarization, poor extinction ratio and wavelength-related energy transmission rate in actual work; more importantly The most important thing is that this device, like all traditional instruments, has a front optical system, which makes the design and development extremely complicated, and the volume and weight increase, and the development cost is high.

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