Two kinds of crosslinked polymers, containing 4-(4 -nitrophenylazo) aniline chromophore groups, were synthesized. Crosslinked polyacrylate was synthesized by polymerization of Dispersed Red-19 (DR-19) diacrylate, whereas crosslinked polyurethane was obtained by the reaction between (β-hydroxy propyl acrylate-DR-1 methacrylate) copolymer and phenol-capped isocyanate-terminated DR-19. The crosslinked polymers were characterized by infra-red spectra, gel content and differential scanning calorimetry. The crosslinked polyacrylate and the crosslinked polyurethane exhibit glass transition temperatures at 125 and 160°C, respectively. Thin, transparent, poled films of both crosslinked polymers were prepared by spin-coating, followed by thermal curing and corona poling at 160°C for 1 h. The second-order non-linear optical properties of the poled films were studied by visible light absorbance measurement according to a one-dimensional, rigid oriented gas model. Long-term stability of the dipole alignment at 140°C was demonstrated for the crosslinked polyurethane.