Polarization holographic element using an azobenzene polymer

摘要

A holographic lens is recorded superimposing two beams with orthogonal linear polarizations on an azobenzene polymer film. The polarization pattern on the interference plane induces two modulations in the media: the volume and the surface modulation. The spatial frequency of the surface relief is twice the one for the volumetric modulation resulting in a holographic lens with two different focal lengths. Additionally, because of the modulated anisotropy induced in the medium, the polarization at the longer focus distance is orthogonal to the polarization at the shorter one. We propose this polarization element to send or detect information in two planes simultaneously or separately by using an analyzer behind the holographic lens.