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. The restricted motion of the nonlinear chromophores during poling provides a possible explanation of this discrepancy. Introducing a restriction parameter ν (0 ≤ ν ≤ 1), we develop a simple model that can account for electro-optic coefficient ratios ranging from 3 to 6.
© 1991 Optical Society of America
Original Manuscript: January 15, 1991
Revised Manuscript: April 3, 1991
Published: November 1, 1991
S. Herminghaus, Barton A. Smith, and J. D. Swalen, "Electro-optic coefficients in electric-field-poled polymer waveguides," J. Opt. Soc. Am. B 8, 2311-2317 (1991)