Large second harmonic generation with in-plane anisotropy induced by photoassisted poling in azobenzene containing polymer films

Summary form only given. It has recently been demonstrated that photoassisted poling (PAP) of azobenzene containing polymers films at room temperature is possible. This poling method utilizes photoinduced trans-cis-trans isomerization of azobenzene groups. By application of a dc electric field during the photoisomerization process, the centrosymmetry in the films is broken at room temperature and the second-order nonlinear optical (NLO) susceptibility is induced. Our recent studies using the PAP on an azobenzene containing polymer indicate that large second harmonic generation (SHG) with in-plane anisotropy is induced by irradiating the sample with p-polarized laser beam at an incident angle other than zero degree. To our knowledge, it is the first time this behavior has been reported.