A Brief Review of Carbazole-Based Photorefractive Liquid Crystalline Materials (original) (raw)

Liquid crystal inorganic hybrid photorefractives

2008 IEEE/LEOS Winter Topical Meeting Series, 2008

We report on the photorefractive properties of liquid crystals sandwiched between windows of cerium doped strontium barium niobate (Ce:SBN). This adaptable design has been used to create devices using pure nematic liquid crystals, ferroelectric nanoparticle doped liquid crystals, and cholesteric liquid crystals. In all these systems, modulation of the liquid crystal molecules is driven by the surface space-charge field from the inorganic windows. Owing to the large effective trap density in the Ce:SBN, high resolution gratings with two-beam coupling gain coefficients of up to 1400 cm-1 have been achieved in the Bragg regime.

Review of Organic Photorefractive Materials and Their Use for Updateable 3D Display

Materials, 2021

Photorefractive materials are capable of reversibly changing their index of refraction upon illumination. That property allows them to dynamically record holograms, which is a key function for developing an updateable holographic 3D display. The transition from inorganic photorefractive crystals to organic polymers meant that large display screens could be made. However, one essential figure of merit that needed to be worked out first was the sensitivity of the material that enables to record bright images in a short amount of time. In this review article, we describe how polymer engineering was able to overcome the problem of the material sensitivity. We highlight the importance of understanding the energy levels of the different species in order to optimize the efficiency and recording speed. We then discuss different photorefractive compounds and the reason for their particular figures of merit. Finally, we consider the technical choices taken to obtain an updateable 3D display u...

Nano-Particle Doped Hybrid Organic-Inorganic Photorefractives

The gain characteristics of liquid crystal photorefractive cells doped with ferroelectric nanoparticles has been measured. The liquid crystal two beam coupling gain is found to reverse in sign and increase in magnitude through the addition of ferroelectric BaTiO 3 nanoparticles, yielding gain coefficients up to 1100 cm-1 in the Bragg regime. We attribute the novel effects of gain reversal and magnitude increase to interactions between the ferroelectric particles' spontaneous polarization and the local liquid crystal flexopolarization.

Applications of photorefractive materials in information storage, processing and communication

Optical Materials, 2003

Photorefractive materials, including traditional electro-optic photorefractive crystals as well as photopolymers and photosensitive glasses, have demonstrated their potential in information systems. In this paper, we describe several applications of various photorefractive materials in information storage, processing, and communication systems. Specifically, we briefly review the applications of the traditional electro-optic photorefractive crystals in optical information processing and volume holographic data storage, then discuss our recent works on the applications of photopolymers, holographic polymer dispersed liquid crystals, and photosensitive glasses in photonic devices for optical fiber communications.

Recent advances in photorefractive polymers

SPIE Proceedings, 2011

Photorefractive composites derived from conducting polymers offer the advantage of dynamically recording holograms without the need for processing of any kind. Thus, they are the material of choice for many cutting edge applications, such as updatable three-dimensional (3D) displays and 3D telepresence. Using photorefractive polymers, 3D images or holograms can be seen with the unassisted eye and are very similar to how humans see the actual environment surrounding them. Absence of a large-area and dynamically updatable holographic recording medium has prevented realization of the concept. The development of a novel nonlinear optical chromophore doped photoconductive polymer composite as the recording medium for a refreshable holographic display is discussed. Further improvements in the polymer composites could bring applications in telemedicine, advertising, updatable 3D maps and entertainment.

High-Performance Photorefractive Polymers

Science, 1994

Photorefractive materials can form "instant" holograms without time-consuming development steps. Their potential applications include image processing, optical data storage, and correction of image distortion, but the cost of crystal growth and preparation has been a primary ...