Abstract

Ultrafast, all-optical soliton trapping logic gates including an inverter, exclusive- OR, and AND are experimentally demonstrated in birefringent fibers. The soliton trapping local gates are three terminal devices with orthogonally polarized inputs, phase-insensitive nonlinear operation, and switching energies of ~42 pJ. The experimental apparatus consists of a 20-m length of highly birefringent optical fiber followed by a frequency bandpass filter. Using a filter with an ~0.2-THz bandpass, the contrast for the exclusive-OR is 8:1, but the output pulses are about 10× broader than the input pulse width. We show a cascadable inverter with an ~4:1 contrast ratio by widening the filter bandpass so the output pulses can propagate as solitons in a fiber. A 4:1 contrast ratio is sufficient for distinguishing between solitons and dispersive waves in fibers, and the reshaping properties of solitons contribute to logic level restoration.

© 1989 Optical Society of America