Ultrafast all optical switching by use of pulse trapping across zero-dispersion wavelength.

Ultrafast all optical switching by use of pulse trapping across zero dispersion wavelength in optical fiber is demonstrated both experimentally and numerically for the first time. Only an arbitrary single pulse among four pulses with temporal separation of about 1.5 ps is successfully picked off with almost perfect extinction ratio. The spectrogram of the optical switching is directly observed using the X-FROG technique. The characteristics of all optical switching are analyzed numerically by the use of strict coupled nonlinear Schrödinger equations and the numerical results are in agreement with the experimental ones. It is interesting to note that although the other pulses are also overlapped with the soliton pulse, they are not trapped.