Spectral and photorefractive properties of nematic liquid crystals from the CHBT family in the terahertz range

Abstract

In this paper, the measurement results of 10 nematic liquid crystals from the homologous series of 4-(trans-4′-n-alkylcyclohexyl) isothiocyanatobenzenes (CHBT) in the range of 0.3–3 THz are presented. Birefringence, refractive indices and absorption coefficients for ordinary and extraordinary rays versus frequency are described. In addition, temperature dependence of these parameters is shown. The purpose of this study was to investigate the effect of alkyl chain length on the properties of liquid crystals in the THz range.

Keywords:

• liquid crystals
• nematic
• terahertz
• spectroscopy

Acknowledgements

The authors thank R. Dabrowski for scientific advice and for providing the LC compounds and N. Palka for providing THz spectrometer and valuable guidance.

This paper received financial support from the Polish Ministry of Sciences and Higher Education, No. O R00 0144 12 ‘Tunable liquid crystal transducers for THz and GHz frequency range’ and Key Project POIG.01.03.01-14-016/08 ‘New Photonic Materials and their Advanced Applications’.