Electro-optic coefficients in electric-field poled-polymer waveguides

Planar waveguides were made from a linear epoxy copolymer of bisphenol-A diglycidyl ether and amino-nitro-tolane. The refractive indices, nTM and nTE, and the electro-optic coefficients, r33 and r13, of the poled nonlinear optical polymer films were determined by measurements of the waveguide modes of these films at a wavelength of 632.8 nm, and the results are reported for both electrode and corona poling. The ratio of the second order susceptibilities was found to exceed significantly the theoretically expected value of 3. Restricted motion of the nonlinear chromophores during poling provides a possible explanation of this discrepancy.