Scanning second-harmonic microscopy of a thin film of sigma-pi copolymer with 2,2 '-bipyridine in the backbone

Scanning second-harmonic microscopy was used to study the lateral distribut ion of the second-order optical nonlinearity of a sigma-pi copolymer [poly( disilanylene-2,2' -bipyridine-5,5' -diyl) ruthenium complex (PDSBpy-Ru)] th in film on a glass substrate. The orientation of the dipolar chromophores a nd establishment of the noncentrosymmetry required by the macroscopic secon d-order optical nonlinearity were resulted from natural coordination of the PDSBpy-Ru molecules to the surface Si-O-H groups on the glass substrate. A homogeneous lateral distribution of the coordination-induced poling was ob served.