Aromatic polyureas: a new class of nonlinear optical polymer with large second-harmonic generation

The second-order nonlinear optical properties of aromatic polyureas are reported. From Maker fringe measurements, the nonlinear d33 coefficient of poled polyurea films with and without pendant chromophores was found to be 20 × 10−9esu and 12 × 10−9esu, respectively, at 1.064μm Aromatic polyurea having no pendant chromophores shows a cutoff wavelength of transmission at 307nm which is the first example of organic NLO materials to be optically transparent at such low wavelengths.