Gain Effects in Optical Storage: Thermal Induction of a Surface Relief Grating in a Smectic Liquid Crystal

Photo-orientation and surface-relief formation have been combined to produce a diffraction grating that could be useful for optical storage. An amorphous film of the azobenzene derivative trisazomelamine was irradiated with linearly polarized light to produce a stable optical grating. Subsequent heating to the liquid-crystalline smectic phase gives rise to surface relief (see Figure), providing a grating with high diffraction efficiency (20 %).