Second-order nonlinear optical properties and relaxation dynamics of aligned cross-linked polyurethanes with hemicyanine-type chromophores

• DOI: 10.1364/josab.15.000393
• Publication Date: 2008-03-20T17:20:35Z
• Authors: Kwang-Sup Lee; Sun-Woong Choi; Han Young Woo; Ki-Jeong Moon; Hong-Ku Shim; Mi-Yun Jeong; Tong-Kun Lim
• Keywords: Chromophore; Poling; Thermal Stability

Three types of different cross-linked polyurethane were prepared by the reaction poly[(phenylisocyanate)-co-formaldehyde] with three hydroxy-functionalized nonlinear optical chromophores. For poled and cured polymers χ(2) values between 16.8 37.4 pm/V, measured at a wavelength 1.064 μm. Thermal stability studies performed on sample having bonding sites vertical–parallel structure chromophore liquid polymer matrix indicated, second-harmonic-generation activity, minimum decay value owing to lattice hardening sites. The relaxation times aligned dipoles in variation poling cross-linking conditions. modes found exist: mode that corresponds partially bonded or free unbonded chromophores, thermal is due an elastically stressed main chain induced elastic field.