Organic materials with a high second-order optical nonlinearity have an important application for the next generation of computing, telecommunications, and other industries. Because of a high electro-optic coefficient and low dielectric constant, N-benzyl-2-methyl-4-nitroaniline (BNA) single crystals have been grown and their optical properties have been extensively studied. In this Letter, a poled BNA thin film material was prepared through simultaneous vacuum evaporation and laser-assisted electrical poling. The linear electro-optic coefficients of BNA were measured by a Young's two-slit interference electro-optic measurement method. The dependence of the resulting electro-optic properties on optical power was explored. Enhancement induced by laser illumination was demonstrated. The BNA thin film can exhibit an r(33) value comparable to that of BNA single crystals.
© 2011 Optical Society of America