Optical frequency shifters based on cascaded second-order nonlinear processes.
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 differencefrequency conversion in a coupled waveguide-to-vertical-cavity structure. For a 50-microm-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/microm. 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/microm.
Gorbounova
O
O
Ding
Y J
YJ
Khurgin
J B
JB
Lee
S J
SJ
Craig
A E
AE