NEAR RESONANCE OPTICAL NONLINEARITIES IN NICKEL DITHIOLENE COMPLEXES

The third-order optical nonlinearity chi(3), linear absorption coefficient alpha, and the two-photon absorption coefficient beta of two nickel dithiolene complexes are reported. The nonlinearities were measured at 1064 nm using 100 ps pulses. Molecular nonlinearities 10(3) times those of carbon disulphide were observed. Two figures of merit were calculated from the data DELTA-n(sat)/alpha-lambda = 5 and n2/2-beta-lambda > 2, where alpha and beta are the linear and two-photon absorption coefficients and n2 the nonlinear refractive index. These figures are compatible with those required for simple all-optical switching devices.