Policryps characterization in the near infrared

We have analysed the electro-optical behaviour at 1550 nm of a new polymer and liquid crystal composite, realized in form of a thick grating. This composite is known as Policryps, acronym that stands for "Polymer Liquid Crystals Polymer Slides", because it shows a sequence of polymeric sheets alternated by layers containing only liquid crystal. Thus, by its intrinsic nature a Policryps is realized in form of grating. It is known that Policryps gratings may have a good diffraction efficiency at 633 nm and they can be electrically switched between the diffracting and non-diffracting states, with time response in the millisecond range. Eventually, Policryps may form a key component in photonic devices for use in telecom applications. With this aim, we made an optical characterization in the telecom C-band of the very first samples produced by University of Calabria (Cosenza, Italy) with this material. We measured the diffraction efficiency versus temperature and applied voltage. We also made a dynamical characterization of the grating switching. By comparison among the results obtained in the red and in the Near Infra-Red (NIR) regions, respectively, we got important information for designing and realizing Policryps samples optimised for working in the C-band.