Abstract

Since the first measurements of large nonlinear optical coefficients in π-electron conjugated systems, such materials have been studied for all-optical applications.[1] Soluble polydiacetylenes are attractive for devices, however, the nonlinear refractive index coefficients, n₂, of these materials in the transparency region are only a few hundred times those of fused silica.[2] Single crystal PTS offers a much larger n₂.[3] However, absorption can limit a material's usefulness and make it marginal for all-optical switching. Frequently, two photon absorption is the limiting factor. We report picosecond pulse, tunable, two photon absorption measurements on single crystal samples of PTS which unveil the two photon resonant structure and indicate areas where the two photon figure of merit T indicates that all-optical switching may be possible.

© 1993 Optical Society of America