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

Abstract:

Ultrafast optical nonlinearities of N,N-dimethylformamide (DMF) are studied by using polarized light at 400 nm. Both nonlinear refraction (NLR) and stimulated Rayleigh-wing scattering (SRWS) depend on the polarization state of incident beam, while two-photon absorption (TPA) changes negligibly with polarization state. The polarization dependence of SRWS originates from that of NLR 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.