Characterization of nonlinear carrier dynamics in silicon strip nanowaveguides

Nonlinear carrier recombination dynamics is characterized in a 450 nm × 220 nm silicon nanowire by employing a time-resolved pump-and-probe experiment. Our results show that the recombination rate is faster at the early stages of the decay as compared to the final stages, in agreement with trap-assisted mechanism. We have also demonstrated that by operating at high carrier density, faster excess carrier generation and recombination can be obtained, which we have used to improve the speed of an all-optical FCA based silicon switch from about 7 to 1 ns.