2-DIMENSIONAL INFRARED-SPECTROSCOPY OF ELECTRIC-FIELD-INDUCED REORIENTATION DYNAMICS OF A MIXED NEMATIC LIQUID-CRYSTAL

A two-dimensional infrared (2D IR) spectrometer has been modified by t he following methods to solve several problems on the 2D IR spectrosco py of electric-field-induced reorientation dynamics of a mixed nematic liquid crystal: (1) The response of the liquid crystal (LC) to an ele ctric field was stabilized by an amplitude-modulated ac electric field . (2) Formulation of an anti-reflection coating (ARC) has been propose d to suppress the interference caused by multiple reflections between IR liquid crystal cell windows. (3) The Fourier transform procedure ha s been modified to correct the phase of the dynamic difference interfe rograms without spectral anomalies. These modifications can provide a better signal-to-noise ratio and reproducible 2D IR spectrum of a mixe d nematic liquid crystal.