Enhancement of Cerenkovian second-harmonic-generation power with ultraviolet irradiation-formed nonlinear optical ((2)(X)) corrugation and channel waveguide

摘要

By irradiation of a UV source through a metallic mask with a chirped periodic or periodic structure and a metallic wire onto vinylidene cyanide/vinyl acetate copolymer, the Cerenkov-radiative second-harmonic generation has been efficiently enhanced, with the channel waveguide having a chirped periodic nonlinear optical susceptibility chi((2)) corrugation. By use of an ArF 193-nm laser close to an inherent absorption line of the copolymer as the UV source, not only a nonlinear optical chi((2)) corrugation with the average period Lambda(s0) = 20 mu m and a chirping index phi(m) similar or equal to 9 but also a channel guide 60 mu m wide were induced. The enhancement factor of the Cerenkovian second-harmonic-generation power achieved was 7.4 times that of a uniform nonlinear optical chi((2)) scheme. This simple UV irradiation method leads to almost the same effect as is obtained by a contact electrode method, showing its feasibility for the Cerenkovian second-harmonic-generation scheme. (C) 1998 Optical Society of America. [References: 9]