THz time-domain spectroscopy on 4-(trans-4'-pentylcyclohexyl)-benzonitril

Abstract

We present a first investigation of liquid crystals in the frequency range around 1 THz using THz time-domain spectroscopy. As a model system we use 4-(trans-4'- pentylcyclohexyl)-benzonitril (PCH-5). The THz refractive indices for the nematic state are comparable to that for visible frequencies. Yet, the THz birefringence of PCH-5 is smaller than its optical birefringence. Furthermore we find that PCH-5 has a rather small absorption.