Chirp controllable all-optical router in a nonlinear directional coupler

We analyzed the evolution of chirped optical pulses in a nonlinear directional coupler by coupled nonlinear Schrödinger equations. It is shown that an optical pulses launched into one channel can couple out from either of the two channels of the nonlinear directional coupler, with the routing determined by the chirp of the pulse. This is different from the previous routing mechanism of the nonlinear directional coupler where routing is determined by the peak power of the pulse. Based on the chirp-dependent feature, all-optical router and switch could be implemented by the pulse chirp modulation.