3RD-ORDER NONLINEAR-OPTICAL PROPERTIES OF NEW POLYFLUOROALKYLSULFANYL-SUBSTITUTED TETRATHIAFULVALENE DERIVATIVES

We investigate the third-order nonlinearities of new polyfluoroalkylsu lfanyl-substituted tetrathiafulvalene derivatives using the degenerate four wave mixing method (DFWM). For each compound, the study of the i nfluence of the concentration on DFWM efficiency leads to the choice o f an optimum solution for which DFWM efficiency R attains its maximum. From the measurements of R versus the pump intensity, we deduce the v alues of third-order susceptibilities chi((3)) and the corresponding s econd-order hyperpolarizabilities gamma. The largest gamma obtained is 10(3) larger than the gamma value of CS2. (C) 1998 Elsevier Science S .A. All rights reserved.