Femtosecond third-order optical nonlinearity of an azobenzene-containing ionic liquid crystalline polymer.

The nonlinear optical properties of an azobenzene-containing ionic liquid crystalline polymer were investigated using single beam Z-scan and optical Kerr effect (OKE) techniques. The nonlinear refractive index of electronic origin (3.1×10(-19) m(2)/W) and the nonlinear absorption coefficient (3.63×10(-13) m/W) were determined with 800 nm femtosecond laser pulses at a repetition rate of 1 KHz. The corresponding one-photon and two-photon figures of merit are determined to be 6.05 and 0.94, respectively, at irradiance of 50 GW/cm(2). The response time of the observed nonlinearities is estimated to be as fast as 300 fs. These experiment results demonstrate that the polymer is a promising candidate for applications in all-optical switching modulators and nonlinear photonic devices.