25ps all-optical switching in oxygen implanted silicon-on-insulator microring resonator

Abstract

We present all-optical switching in oxygen ion implanted silicon microring resonators. Time-dependent signal modulation is achieved by shifting resonance wavelengths of microrings through the plasma dispersion effect via femtosecond photogeneration of electron-hole pairs and subsequent trapping at implantation induced defect states. We observe a switching time of 25 ps at extinction ratio of 9 dB and free carrier lifetime of 15 ps for an implantation dose of 7×10¹² cm^-2. The influence of implantation dose on the switching speed and additional propagation losses of the silicon waveguide – the latter as a result of implantation induced amorphization – is carefully evaluated and in good agreement with theoretical predictions.