Fourier transform spectrometer using a multielement liquid crystal display

摘要

Fourier transform spectrometer using a multielement liquid crystal display. A ferroelectric liquid crystal mask is used as an optical encoder for a solid-state Fourier transform spectrometer. A 1x64 element array was striped and used as a 1x4 element device. The device intersected dispersed radiation and encoded each spectral component thereof with a carrier signal by applying half-wave potentials to each of the four striped (1x16) liquid crystal elements which varied the transmitted amplitude of the light from 0.03% to 28% of full scale. The light was spectrally recombined and imaged onto a photomultiplier and the resulting carrier frequencies (and their amplitudes) detected by Fourier transformation of the time-varying signal. Spectra of colored-glass filters were taken to demonstrate the spectrometer.