Pump-induced frequency shifting of switched pulses in an interferometric all-optical switch

The induced frequency chirping of switched pulses in an interferometric all-optical switch that uses pump-induced nonlinear phase shifts is investigated. Using a nonlinear fiber Sagnac interferometer switch, it is shown that switched pulses suffer from frequency shift and broadening and can be compressed by using an anomalous group-velocity-dispersion fiber. It is also demonstrated that picosecond probe pulses can be switched while retaining their temporal and spectral profiles if pump-probe walk-off is employed.