Abstract

Photoinduced orientation of azobenzene chromophores in polymeric host materials has been broadly explored for holography and related diffractive optics applications [1,2]. Illumination of the chromophore with polarized light rotates the trans isomer perpendicular to the polarization, resulting in spatially modulated birefringence. In the dark, photo-oriented chromophores thermally relax to a random orientation resulting in a decay of birefringence over a wide range of time scales depending on the chromophore molecular architecture and glass transition temperature. A related phenomenon is that illumination with spatially modulated light (e.g. from two interfering laser beams) generates strong photo mechanical anisotropy in azo-polymer films, resulting in surface mass transport and the formation of periodic surface relief gratings [3,4].

© 2017 IEEE