3RD-ORDER NONLINEAR-OPTICAL RESPONSE OF A NEW EPOXY-BASED LINEAR POLYMER

An investigation was made of the nonlinear refraction of a newly synth esised polymer structure based on the diglycidyl ester of bisphenol A. The nonlinear optical chromophore was 4-aminobenzene. A degenerate tw o-wave interaction was used to determine the nonlinear susceptibility chi((3))(omega, omega, -omega, omega) = (4.7 +/- 2.4). 10(-8) sgs esu at the wavelength of the second harmonic of YAG:Nd laser radiation. An investigation of the kinetics of formation and erasure of dynamic gra tings revealed the existence of two characteristic grating-erasure tim es: tau(1) less than or equal to 20 ns and tau(2) less than or equal t o 10 mu s. An analysis was made of possible mechanisms of the nonlinea rity of the refractive index of the new structure. The role of the tra ns-cis photoisomerisation of azo ocompounds and the influence of these compounds on the nonlinear optical properties of the investigated pol ymer were noted.