Novel permanent and electrically switchable diffraction gratings made of polymeric slides and nematic liquid crystal layers

This study proposes a novel technique in fabricating permanent switchable gratings in composite materials which are characterized by both lower scattering losses and lower driving electric fields in comparison with usual PDLC gratings. Such a technique exploits the interference pattern produced by two UV (cw) laser beams. Acting on a solution of highly mutually soluble pre-polymer and LC components sandwiched in a glass cell, the interference pattern yields a grating which is composed by a sequence of continuously aligned LC layers separated by isotropic polymer slides. This is the so called POLICRYPS (polymer-liquid crystal-polymer-slides) morphology obtained by a simple and low cost technique.