Abstract

The large measured nonresonant third order nonlinear optical susceptibility, χ⁽³⁾, of the organic polymeric system the polydiacetylenes has been attributed to their delocalized one-dimensional electronic states[1]. However, the lack of dynamical data has prevented the determination of the effect of the strong electron-phonon coupling in these materials on excited state life-times [1]. Further such coupling could slow the off-resonant nonlinear response (i.e. the change of index of refraction due to χ⁽³⁾) from its "instantaneous" (due to adiabatic following) value [1], which in principle could limit the suggested use of these materials in ultra-fast optical signal processing schemes based on χ⁽³⁾ [2]. In the following we describe the first experimental determination of some of these dynamical effects.

© 1986 Optical Society of America