Stressed Liquid Crystals Materials for Light Modulation

KSU.262

Abstract: Light modulators operating at fast frame rates (few hundred hertz or faster) are in great demand for optical data processing and adaptive optics applications as well as for color projection displays using time sequential color scheme.  Much progress has been made in the last thirty years in developing optical switches or modulators, but current devices are not very satisfactory for many applications.  Liquid crystals are an interesting medium for electro-optical effects due to their large optical birefringence and dielectric anisotropy.  It is only natural that investigators would consider forming electrically controllable birefringent plates made of liquid crystalline materials.  Unfortunately, such liquid crystal based light modulators have relatively slow response times and cannot be operated typically beyond video rates.  Here we have developed a new light modulating material using interconnected unidirectionally-oriented microdomains of a liquid crystal, dispersed in a stressed polymer structure.  The light modulating material is prepared by dissolving the liquid crystal in an uncured monomer and then curing the monomer so that the polymer forms a well-developed interpenetrating structure of polymer chains or sheets that is uniformly dispersed through the film.  The new materials are optically transparent and provide phase modulation of the incident light opposed to the low driving voltage, linear electro-optical response, and absence of hysteresis.  It has been shown that these new materials can be successfully used in display applications, optical modulators, and beam steering devices.  This technology is related to Kent State University technology KSU.243 and is available for non-exclusive licensing.

Applications:

•          Displays, optical modulators, beam steering devices, telecommunication systems,  and others

Advantages:

•          Optical transparency,  fast switching, relative large active area of film possible, diffraction efficiency, absence of hysteresis, simple production with economic significance

Inventors:  Dr. John L. West, Dr. Anatoliy Glushchenko, Dr. Guoqiang Matt Zhang