We propose a novel scheme for an optical frequency shifter that exploits cascaded second-order nonlinearity in a semiconductor material. The cascade comprises a sum-frequency interaction followed by a difference-frequency conversion in a coupled waveguide-to-vertical-cavity structure. For a 50-μm–long planar waveguide, efficient conversion is supported over an effective −3-dB bandwidth of 39 nm at a pump power density of 3.3 W/μm. A longitudinal in-plane cavity can reduce the required pump power density so that effective conversion occurs over a bandwidth of 20 nm at a pump power density of 6 mW/μm.
© 1996 Optical Society of America
O. Gorbounova, Y. J. Ding, J. B. Khurgin, S. J. Lee, and A. E. Craig, "Optical frequency shifters based on cascaded second-order nonlinear processes," Opt. Lett. 21, 558-560 (1996)