Ultrafast all-optical logic gates based on soliton trapping in fibers

Ultrafast all-optical soliton-trapping logic gates, including an inverter, exclusive OR, and AND, are experimentally demonstrated in birefringent fibers. The soliton-trapping logic gates are three terminal devices with orthogonally polarized inputs, phase-insensitive nonlinear operation, and switching energies of ~42 pJ. Using a 0.2-THz bandpass filter, the contrast ratio for the exclusive-OR gate is ~8:1, but the output pulses are ~10 times broader than the input pulse width. By widening the filter bandpass to 0.58 THz, an inverter is demonstrated with an ~4:1 contrast ratio and output pulses that can propagate as solitons in a fiber. Numerical simulations show that the output from the inverter can be cascaded to other trapping gates.