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 Čerenkov-radiative second-harmonic generation has been efficiently enhanced, with the channel waveguide having a chirped periodic nonlinear optical susceptibility χ(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 χ(2) corrugation with the average period Λs0 = 20 μm and a chirping index øm ≃ 9 but also a channel guide 60 μm wide were induced. The enhancement factor of the Čerenkovian second-harmonic-generation power achieved was 7.4 times that of a uniform nonlinear optical χ(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 Čerenkovian second-harmonic-generation scheme.
© 1998 Optical Society of America
Heihachi Sato, Hiroaki Matsuno, and Iwao Seo, "Enhancement of Čerenkovian second-harmonic-generation power with ultraviolet irradiation-formed nonlinear optical χ(2) corrugation and channel waveguide," J. Opt. Soc. Am. B 15, 773-780 (1998)