Abstract

Our interest is in the bulk nonlinear optical properties associated with suspensions of conducting particles. These particles can exhibit a discrete line spectrum if they are smaller than the Bohr radius of the free carrier. In principle, the band gap can be engineered to lie in the visible region and, as a result of local field effects, distributions of such particles can possess large optical nonlinearities and can exhibit bistability, making them suitable for optical switching and storage applications. Several physical mechanisms contribute to the nonlinearity, each having different characteristics with respect to wavelength sensitivity and response time. These mechanisms include quantum confinement effects, thermal nonlinearities, and electrostrictive forces. We present results on the scattering and modulation of light from colloidal gold. Two application areas are largearea switching of optical transmission and high-density pixelation of switching elements, both of which are ideal for low-power narrowband optical interconnects.

© 1990 Optical Society of America