Topic:A review of Nonlinear Optics and Surface Effects in Complex fluids With a Comparison to Light Modulation in Crystalline Solids

Speaker: Dr. Matthew E. Edwards, Spelman College

Date & Time: Thursday, October 18, 2001, 1:00 P.M.

Place: Room 140 VMC

The characterization of materials is critical for their development into useful devices. We have investigated the surface effects (elastic properties) and non-linear optics of microemulsions (ternary complex fluids__those microemulsions, made as combined systems of water/an aliphatic oil/and the AOT (sodium di-2-ethylhexyl sulfosuccinate surfactant); our results indicate that both phenomena depend on anisotropy which is conferred by interaction between Particles of the respective system. Specifically, the Kerr coefficient ( related to the c⁽³⁾ electrical susceptibility) increases with the square of a microemulsion's dispersed phase concentration. From characterizing these systems, we have developed selected ones into high-speed light modulators. Here, we illustrate their functionality. In addition, we are currently considering the growth and electro-optical properties of single crystal thin films, our desire is to measure properties such as the natural birefringence d_o, the half-wave voltage V_l/2, the figure-of-merit F, and the relevant tensor elements r_ij, for such materials as NPP (N-4-nitrophenyl-(L)-prolinol) and Lithium Niobate, and to develop selected material systems into high-speed solid state light modulators, These properties are based on the c⁽²⁾ and/or c⁽³⁾ electrical susceptibilities. We compare the two types of modulators and suggest which operates better in various applications.

Prof. Matthew E. Edwards obtained his M.S. and Ph.D. from Howard University in 1975 and 1977 respectively. He is currently associate professor of Physics in Spelman College, Atlanta, GA. He is the recipient of the 2001 presidential award for excellence in teaching. He is an active member of the American Physical Society, and American Association of Physics Teachers, etc. He is the author of several scientific publications in scientific journals.