Liquid crystalline polymers under uniaxial mechanical stress as observed with modulated waveguide spectroscopy

The reorientation of a liquid crystalline statistical side chain polymer un der application of a dynamic uniaxial stress is studied using mechanical mo dulated waveguide spectroscopy (MMWS). It is found that a tilt angle of the order of 5 degrees is induced in the SmA phase by compressions of 19 nm of the originally homeotropic orientation with a pronounced orientational pro file normal to the cell. The dependence of this mechanical reorientation pr ocess on the thickness modulation amplitude and frequency is discussed.