SOLITON DRAGGING IN DISCRETE AND DISTRIBUTED-AMPLIFIERS

We introduce erbium-doped fibre amplifiers (EDFA) into soliton-draggin g logic gates (SDLG) to improve their performance in terms of switchin g energy, fan-out and tolerance to timing jitter. In particular, we ex perimentally and numerically examine the frequency shifts associated w ith soliton dragging for orthogonally polarized pulses interacting in discrete and distributed amplifiers. We show that EDFA asymmetrize the interaction between pulses, leading to a frequency shift even when pu lses completely walk through each other. The gain can increase the fan -out and/or reduce the switching energy, while proper positioning of t he amplifier can loosen the timing restrictions for SDLG. We find reas onable agreement between calculations and measurements in the discrete amplifier case. However, discrepancies for the distributed amplifier case may result from non-uniform gain profiles along the length of the amplifier.