Abstract

Organic polymers not only have large, nonlinear-optical susceptibility but also various advantages, such as flexibility, a high optical damage threshold, and ease of film growth. We have observed second-harmonic generation (SHG) by using a vinylidene cyanide/vinyl acetate (VDCN/VAc) copolymer at Nd:YAG 1.06-μm and Er:YAG 2.94-μm laser lines.^1,2 It is impossible to phase match organic polymers by adjusting the setting angle as one does a crystal; thus, the SHG power has been improved to satisfy the phase-matching condition with slab-waveguide and Cerenkov-radiation schemes.^3,4 However, film thickness and optical smoothness of the interface between the film and cladding must still be controlled. Optical nonlinear susceptibility ${\chi }_{\text{eff}}^{\left(2\right)}$ generally induced by applying the poling field in organic polymer or copolymer; applying the poling field with a periodically inverted configuration produces periodic corrugation in the optical nonlinearity to satisfy the phase-matched condition. In this paper we report the enhancement of SHG power with a periodically poling corrugated VDCN/VAc copolymer at 2.94-μm Er:YAG laser radiation.

© 1991 Optical Society of America