Liquid crystal photonics: Optical switching and image storage by means of nematic liquid crystals and ferroelectric liquid crystals

Manipulation of light by light as a stimulus by the use of liquid-crystalline materials was explored, which was aimed at optical switching, optical image storage and optical display. Two types of the liquid-crystalline materials are used: nematic liquid crystals (NLCs) and ferroelectric liquid crystals (FLCs). Several kinds of optical switching and image storage systems were demonstrated by means of photochromic molecules and photosensitive LC alignment layer to induce the change in alignment of the LCs: 1) Fast nematic (N) to isotropic (I) phase transition of azobenzene LCs was induced by the laser pulse in two modes of analysis, transmission mode and reflection mode. 2) Optical switching in FLCs doped with the azobenzene was investigated with regard to photochemical flip of polarization of the FLCs. 3) Optical control of polymer-dispersed LC (PDLC) was explored by means of the azobenzene LC. 4) Optical switching and fabrication of nonrubbed alignment layer based on the novel photophysical principle was achieved in terms of photosensitive polyimide as an LC alignment layer. 5) Optical control of conductivity was performed by the use of LC thiophene derivatives.