Resonant Third-Order Optical Nonlinearities of the Stretch-Oriented Cyanine-Dye-Doped Poly(vinyl Alcohol) Films

Stretch-oriented cyanine-dye-doped poly(vinyl alcohol) (PVA) films were prepared at temperatures above the glass transition temperature of PVA. The optical absorption spectra of the stretch-oriented films exhibited an anisotropy. The third-order nonlinear optical susceptibilities of the stretch-oriented films were measured parallel and perpendicular to the stretching direction by the resonant femtosecond degenerate four-wave mixing (DFWM) technique, and a high anisotropic X(3) was observed for the uniaxially stretch-oriented cyanine-dye-doped PVA films.