All-optical switching of slow light in nonlinear Bragg grating coupler

This work demonstrates, numerically, that the nonlinear interactions of slow-light modes allow for all-optical switching of slow pulses between the waveguides controlled by the input power. Dynamic transformation and switching of optical pulses can be realized through interactions between slow-light modes in coupled waveguides with the phase-shifted Bragg gratings. Nonlinearity enables compensation of dispersion-induced pulse broadening through the formation of a new type of gap solitons which periodically tunnel between the waveguides while preserving a constant width. It was found that the propagation velocity of such gap solitons and the corresponding pulse delay can also be actively tuned by varying the input power.