By introducing sinusoidal chirping into a periodic nonlinear optical susceptibility, we propose that the Čerenkov radiative second-harmonic generation is greatly enhanced in theoretical calculations, and this is demonstrated with an organic copolymer. The use of nonlinear optical chirping with an average χ(2) period of 20 µm, a modulation period 200 µm (modulation index ≃9), and a total length of 2 mm with the VDCN/VAc copolymer film yields enhanced second-harmonic generation by a factor of ~7. This enhancement is much greater than that with a uniform periodic χ(2) film with a period of 60 µm, which is consistent with the theoretical estimates.
© 1994 Optical Society of America
Heihachi Sato, Yuji Azumai, and Hidehisa Nozawa, "Effect of chirped nonlinear optical susceptibility corrugation on the Čerenkovian second-harmonic power in a slab waveguide," Opt. Lett. 19, 93-95 (1994)