Method of realizing compact Fourier transform spectrometer without moving parts based on birefringent liquid crystal

Abstract

A method of realizing a compact Fourier transform spectrometer is proposed in this work, which is based on the polarization interference in a single layer of birefringent liquid crystal (BLC). The continuous interference between the ordinary light and the extraordinary light is driven by a continuously adjusted electric field. Benefiting from the single-layer configuration with no moving parts, the spectrometer is easily miniaturized. The method to realize the spectrometer is theoretically analyzed and experimentally demonstrated by a layer of nematic BLC with a 100-μm thickness.

Room‐Temperature, High‐SNR Upconversion Spectrometer in the 6–12 µm Region

“…FTIR systems with fixed components have been realized by exploiting interferograms produced in the spatial rather than in time domain. [ 10–13 ] These new FTIR (spatial type) systems have improved mechanical stability but have the same major drawback as the conventional FTIR (temporal type) in terms of the necessity of using cryogenically cooled MIR detectors to achieve a practical SNR performance or measurement speed. A novel technology that is emerging as a strong alternative to both types of FTIR systems is the MIR upconversion spectrometer (MIRUS) [14–22 ] .…”