Total Internal Reflection(TIR) Raman Spectroscopic: Study on Liquid Crystal Orientation Process by Electric Field

Abstract

Time-resolved total internal reflection(TIR) Raman spectroscopy was applied to study the electric field induced orientation change of a nematic liquid crystalline cell(sample:4-hexyl-4'-cyano-biphenyl,6CB). The measurement was performed by using a spectrometer with a f-value of 1.8 and a Nd-YAG pulse laser(pulse width; 15ns). The time resolved TIR Raman spectra were analyzed by using Raman scatter's tensor ratios determined by static polarized Raman mesurements and calculated electric fields near a liquid crystal-electrode interface. The results revealed differences between the time-course of the orientation changes of the director near the interface(several hundreds A) and that in the bulk.