Enhanced all-optical tuning of leaky eigenmodes in photonic crystal waveguides

We demonstrate all-optical switching in an active two-dimensional photonic crystal waveguide, observing as large as 16 nm blueshifts of a leaky eigenmode at 839 nm and switching ratios of almost 70%. These results are larger than those previously observed in similar experiments performed on passive photonic crystal waveguides; the enhancement is due to resonant photageneration of carriers by In0.12Al0.2Ga0.68As quantum wells in the core of the waveguide. The effective change in the refractive index of the structure is similar to 10(-2), with a rise time of similar to 1 ps and a decay time of similar to 10 ps, potentially allowing high-speed switching and fast modulation rates.