All-optical on-chip dynamic frequency conversion

Dynamic processes allow controlling light through a fast modification of the optical properties of the confining structure while the light is present in it. Here, we demonstrate the on-chip dynamic frequency conversion of a light signal by performing this modification through a short optical switching pulse co-propagating on-chip with the signal. A frequency-dependent propagation velocity allows the switching pulse to overtake a co-propagating signal pulse running ahead while on its way driving the dynamic process. We show a dynamic frequency shift of up to 70 GHz with a conversion efficiency of up to 25%. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4757614]