CAREER: Optoelectronic Nanocomposites: Controlling the Properties of Bulk Ceramic Heterostructures using External Electric Fields.

University Of California-Riverside, Riverside CA

Investigators

Abstract

NON-TECHNICAL DESCRIPTION: The ability to bend (refract) light using transparent materials is familiar and useful in many devices such as cameras and telescopes. Light refraction properties of a special class of materials called electrooptic materials can be controlled using electric fields. Since electric fields are relatively easy to generate and change, electrooptic materials allow light paths to be changed 'on the fly'. Electrooptic materials could find a host of new applications if the electrooptic response could be attained faster or using smaller fields. The aim of this CAREER project is to extend the applicability of electrooptic ceramics by using a composite approach. Typically ceramic composites are opaque, but by carefully controlling their structure large ceramic materials whose light transmittance properties can be controlled by applying electric fields will be produced. These materials should be useful in a wide array of consumer electronics such as digital cameras and advanced applications especially in the laser field. As part of the integrated educational effort the research will be used to motivate young scientists and engineers through workshop-like demonstrations. Light interaction with materials is relatively easy to demonstrate allowing the research to be brought to life for diverse groups of students. TECHNICAL DETAILS: The refractive index is one of the most fundamental optical properties ? it controls the degree to which light is refracted by a material. The refractive index of electrooptic materials can be controlled using electric fields. Materials with high electrooptic response are already available, but often the high fields and/or slow switching times required make them prohibitive for many applications. This CAREER project will produce bulk heterostructures from oxides with different properties in order to control optical properties using small applied fields without compromising large electrooptic effects. Judicious use of oxide mixtures (composites) can tune response producing more versatile materials. The strategy is to consolidate oxide nanopowders into large sized nanocomposites without losing the nanostructure. Some of the specific scientific issues the research will elucidate are: the role of nanostructured length scales (grain sizes) and dissimilar phases (interfaces) on transparency and optoelectronic properties in bulk sized ceramics. If successful, these materials will be used for optical beam deflection and generation of giant optical pulses in devices ranging from consumer electronics to high powered lasers. In addition there is a detailed plan to develop workshop-like demonstrations for students who learn in different ways. These demonstrations will be conducted in various venues including university dormitories and high school classrooms in order to reach distinct student populations.