Liquid-crystal-based terahertz tunable Lyot filter

Abstract

A two-element tunable Lyot filter operating in the terahertz (THz) frequency range is demonstrated. The central bandpass frequency of the filter can be continuously tuned from 0.388to0.564THz (a fractional tuning range of 40%) using magnetically controlled birefringence in nematic liquid crystals. The transmission bandwidth is 0.1THz and the insertion loss of the present device is 8dB due to the scattering of LC molecules in the thick LC cells. This filter can be operated at room temperature.