Abstract

The magnitude and response time of the third-order nonlinear coefficient were measured in dilute solutions of polyacetylene and thin polythiophene films using four-wave mixing techniques. In soluble polyacetylene the relatively large (> 10⁻⁹ esu) and fast (<20-ps) response, comparable to results in solid samples, seems to indicate that interchain interactions do not play a significant role in the nonlinear response. In polythiophene and its derivatives, one of the largest values of the nonlinear optical coefficient (> 10⁻⁸ esu, <20 ps) was measured within the absorption band.

© 1988 Optical Society of America