Fourier transform infrared ATR and transmission study of the response of liquid crystalline 5CB to electric excitation

Attenuated total reflection and transmission results on the electric pertur bation of liquid crystalline 5CB between orienting walls are compared. In t he interface between a wall and the bulk a depth dependent average orientat ion of the director is observed in the presence of ac fields. In this trans ition region the dynamic behaviour of the liquid crystal shows a faster and qualitatively different response from the bulk. Near the orienting wall th e effect of the field perpendicular to the wall depends on the field direct ion as indicated by the observation of a large response component at the ac frequency.