3RD-ORDER OPTICAL NONLINEARITIES OF A POLYMERIC FILM DOPED WITH A NOVEL ZWITTERION, DEMI-3CNQ

We report the use of the z-scan technique with 15 ps duration pulses a t 532 nm, to measure the optical nonlinearity in a polymer film contai ning a novel zwitterionic molecule in dispersion. The DEMI-3CNQ zwitte rion was formed by a heat-induced reaction of the components of the TE A(TCNQ)(2) charge-transfer salt contained in a PMMA matrix. We have fo und a bleaching nonlinearity with a saturation irradiance I-s = 1.5 GW cm(-2) and an associated nonlinear refractive index n(2) = +7.0 x 10( -3) cm(2)GW(-1). The potential of this material for optical switching applications is discussed using the relevant figures of merit.