Ultrafast time response of optical nonlinearity in polysilane polymers

Abstract
Ultrafast relaxation kinetics of third-order nonlinear susceptibility χ(3) of polysilane polymers was measured using both the picosecond Kerr gate and forward degenerated four-wave mixing. The relative contributions from various nonlinear decay mechanisms were estimated from the time response. The third-order nonlinear response was measured to be faster than 3 ps arising from electronic mechanism. A slower component is assigned to the refractive index grating due to light pressure.