Polarization-dependent ultrafast optical nonlinearities of N,N-dimethylmethanamide at 400 nm

Abstract:

Ultrafast optical nonlinearities of N,N-dimethylmethanamide (DMF) are studied by using polarized light at 400 nm. Both nonlinear refraction and stimulated Rayleigh-wing scattering (SRWS) depend on the polarization state of incident beam, while two-photon absorption changes negligibly with polarization state. The polarization dependence of SRWS originates from that of nonlinear refraction via self-focusing effect. Third-order susceptibility elements of DMF were determined, and a method to distinguish the multi-photon absorption signal from SRWS in Z-scan is provided. These results are helpful for the nonlinear optical research of the novel materials dissolved in DMF.

Key words:DMF, nonlinear refraction, two-photon absorption, stimulated Rayleigh-wing scattering, polarization.