Ferroelectric liquid-crystal-based binary optical memory employing feedback

Abstract

A two-dimensional bit-oriented refreshing optical memory that is loosely based on the design of an electronic flip-flop is presented. The test system consisted of two amorphous-silicon liquid-crystal optically addressed spatial light modulators placed into an inverting configuration to provide a stable refreshable memory element. A description of the optically addressed spatial light modulator device and its operation is presented. The optical design of the memory with the optically addressed spatial light modulator is described, and timing and component requirements are delineated. The results and analysis of testing for a one-pixel memory system are reported. The expected requirements and limitations of a multipixel system are discussed.

Soft memory in a ferroelectric nanoparticle-doped liquid crystal

“…Memory effect in soft materials plays a crucial role in a wide range of physical properties and has drawn a great deal of research interest in fundamental and applied physics by exhibiting remarkable physical phenomena, such as a rewritable shape-memory effect in a semicrystalline poly(ε-caprolactone) [1], industrial applications of polymershaped memories in robotics [2], effect of soft memory in biocompatible devices [3], multilevel nonvolatile transistor memories in a star-shaped poly((4-diphenylamino)benzyl methacrylate) [4], and memory effects in soft polymer foams due to magnetoelectric coupling [5]. Liquid crystals (LCs), in particular, show fascinating memory effects, such as a binary optical memory effect in ferroelectric LCs [6], frustrated topological memory effects in nematic LCs [7], electric field driven bi-stable memory functions in dye-doped nematic LCs [8], and a surface-anisotropic-alignment memory effect in a nematic LC [9]. Recently, the long-range orientational order in LCs has been exploited very effectively to transfer order onto various nanoparticles [10][11][12][13][14].…”