Properties of birefringence and surface relief gratings inscribed on azopolymer thin films using various interference patterns

Abstract

Polarization properties of transmitted and diffracted orders from holographic diffraction gratings inscribed on azopolymer thin films have been analysed for selected polarization configurations of the interfering beams. Using the Jones matrix formalism, the polarization states of transmitted and diffracted orders are predicted considering either a pure polarization grating or a combination of a polarization and a surface relief grating for co-and contra-circularly polarized beams, linearly orthogonal polarized beams (p + s) and parallel in-plane polarized beams (p + p). In the (p + s) setup, the formation of a twice-frequency surface modulation, whose origin comes from an additional interference between two first diffracted orders, is reported. In the case of the (p + p) polarization configuration, the optical erasure process with a single beam is investigated at various levels of diffraction efficiency with the aim of finding optimum conditions to duplicate surface relief gratings using a polarized single beam exposure.