Soliton logic gate using low-birefringence fiber in a nonlinear loop mirror

We demonstrate, using numerical simulations, a new all-optical logic gate that combines the mechanisms of soliton dragging and nonlinear-optical loop mirrors (NOLM’s). The design uses specially wrapped low-birefringence polarization-maintaining fiber, which we recently demonstrated in the NOLM configuration. Combining the soliton dragging and NOLM effects increases the timing window of the gate, and using the low-birefringence fiber minimizes the number of cross splices required. For example, we show that by using only one cross splice we can achieve a switching energy of 5.3 pJ and a total timing window of 3.3 pulse widths. We also present a set of design rules for our low-birefringence NOLM.