Photorefractive Bragg diffraction in high- and low-molar-mass liquid crystal mixtures

Abstract

Orientational photorefractive Bragg diffraction is observed in high- and low-molar-mass liquid crystal mixtures doped with fullerene (C60). These novel materials are in a nematic phase without phase separating. In the functionalized materials, we observe a high two-beam coupling gain coefficient (Γ=75 cm−1) with a low applied field of 4 V/μm, low total losses (32 cm−1 including scattering, reflection, and absorption), a high diffraction efficiency (9%), and response time of 200 ms.

Dielectric properties of laser-induced conditions in a hybrid composite made by doping a side-chain liquid crystalline polymer

“…Wave-mixing experiments, extensive in the literature, including different kinds of materials and lasers, claims various grating formation mechanisms or combination of these mechanisms. In fact diffraction characters of this material were previously published [12][13][14][15]28]. Due to the anisotropic property of LC, its capacitance is dependent on external effects.…”

“…This phenomenon has potential applications such as holographic data storage. Polymer-dispersed LC is another exciting area in related research on highly efficient orientational photorefractive effects [10][11][12][13][14][15][16].…”

Materials Design and Physics of Organic Photorefractive Systems

“…The isolated LC domains also require higher switching voltages (several volts per micrometer). An alternative way is to dope high molecular mass LCs (HLCs), for example liquid-crystalline side-chain polymers, [76] into the LLC. Only the LLC ions are mobile and can contribute to the charge transport.…”

Temperature dependency of impedance spectroscopy behaviors in side-chain liquid crystalline polymer

“…In technology, LC is commonly preferred to be used in their doped forms so that the considered effects would be dominant. Actually polymer-dispersed LC is among one of these categories in related research on highly efficient orientational photorefractive effects [12][13][14][15][16][17][18]. Electrical properties of a side-chain liquid crystalline polymer (SLCP) composite were investigated for laser-induced circumstances [19].…”