9361398 Zang Two-dimensional spatial light modulators (2DSLM) are key to every optical signal/computing architecture. However, 2DSLMs have not been well developed for practical applications due to a lack of high quality nonlinear optical (NLO) material and inadequacies in the device concept. Current 2DSLMs greatly limit the development of optical signal processing. MetroLaser proposes to develop an innovative, two-dimensional optically addressed, thresholding, and erasable 2DSLM. The proposed 2DSLM is based on a nonlinear Fabry-Perot interferometer modulator with cavity material made of bacteriorhodopsin (BR), a newly developed nonlinear optical (NLO) photochromic protein. The proposed device utilized the large refractive index change of BR in the Fabry-Perot cavity to alter the device optical transmission. This device is expected to have excellent spatial resolution, high optical sensitivity, easy erasability, simple, adjustable thresholds, random address capability, enormous pixel density and high contrast. If this project succeeds, it will be a major breakthrough in the real-time, high speed optical implementation of pattern recognition, optical computing, neural network, and nonlinear imaging processing. The Phase I effort will consist of analytical and experimental work aimed at evaluating spatial resolution, sensitivity, write/erase cycles, and fabrication procedures of the BR-SLM. ***