Abstract

Photosensitive biomolecular materials showing strong third-order nonlinear optical effects are of great interest for optical signal processing and computing. One of the active nonlinear biomolecular materials is a protein called bacteriorhobopsin (BR) found in the purple membranes (PM’s) of halobaterium halobium. In application to integrated optical devices the molecules must first be assembled into thin films. The Langmuir-Blodgett (LB) technique is one way of making these films with the required precision in both film thickness and molecular orientation. In this paper we report the preparation and third- order nonlinear characteristics of PM LB films. The third-order susceptibility of the films is measured, and the strong third- order optical nonlinear phenomena at very low light intensity are observed.

© 1993 Optical Society of America