Molecular Crystals and Liquid Crystals Science and Technology. Section A. Molecular Crystals and Liquid Crystals, Vol.251, 61-72, 1994
Optical Frederiks Transition - Bulk Director Reorientation Measurement from Diffraction Pattern and Tir Investigations
Three different results on optically distorded nematic films are presented. They have been derived from T.I.R. experiments and graphical discussion on the observed far field diffraction pattern. First, the optically induced director reorientation profile (radial dependence) in a nematic film can be much more larger than the pump beam profile. Second, a maximum reorientation tilt angle as large as 80 degrees can be obtained and third, the same sample can be focusing, diffracting and defocusing depending on the pump power. The later is a pure thermal effect and occurs as the boundary conditions are very weak.