Photoinduced Spontaneous Surface Relief Gratings In Azo Glass Material

Abstract

This work investigates the formation of surface relief gratings (SRGs) on an azobenzene thin film when irradiated with a 532nm laser. The formation of linear gratings is created when exposed to a linearly polarized light, with the gratings formed parallel to the lights polarization. Adjusting the orientation of the lights polarization will result in a matching grating in the same direction. The growth of the SRGs is monitored by following the intensity of the first node via pass-through diffraction. The intensity pattern shows two operating functions over time, one which is actue and one which is longer. In attempt to obtain chirality from an isotropic beam, the azobenzene sample was rotated during growth period to obtain non-uniform, globule shaped structures which indicate non-symmetric properties. The SRGs formed are observed and studied through atomic force microsocpy, in which the grating pitch, orientation and overall structure can be observed. The resulting formations from rotating the sample at incidence, does in fact show varying degrees of anisotropy, however they do not show any clear or certain chiral features.