Multi-wavelength regeneration of phase encoded signals based on phase sensitive amplifiers

Abstract

Future high capacity optical links will have to make use of frequent signal regeneration to enable long distance transmission. In this respect, the role of all-optical signal processing becomes increasingly important because of its potential to mitigate signal impairments at low cost and power consumption. More substantial benefits are expected if regeneration is achieved simultaneously on a multiple signal band. Until recently, this had been achieved only for on-off keying modulation formats. However, as in future transmission links the information will be encoded also in the phase for enhancing the spectral efficiency, novel subsystem concepts will be needed for multichannel processing of such advanced signal formats. In this paper we show that phase sensitive amplifiers can be an ideal technology platform for developing such regenerators and we discuss our recent demonstration of the first multi-channel regenerator for phase encoded signals.

A novel scheme of cascaded four-wave mixing for phase-sensitive amplification in nonlinear optical fibre

“…where θ = θ1 + θ2 − K1L1. Thus, the PSA gain G de-pends upon signal phase only and hence two pumps and input signal need not be synchronized by phase locking, which is otherwise a difficult process to achieve in optical domain (22,29). It is also observed that PSA gain depends upon amplifier length (HNLF2 length), nonlinear coefficient (γ ) and pump powers.…”

“…More-over, pump waves are also present at the output of PSA, in addition to amplified signal, which acts as classical noise source. In frequency degenerate, PS-FOPA signal and idler are present at the same frequency, hence there is no shift in operating frequency (4,22,23). However, in this technique, an optical phase locking between signal and pump waves is required.…”

All-Optical 40 Channels Regenerator Based on Four-Wave Mixing

“…All-optical signal regeneration is the key technology to improve the signal quality by restoring the original shape of the optical signals [8]. All optical regeneration results in reduction of noise in the optical signals for high capacity optical links at a low cost and low power consumption [9]. Based upon their functionality, optical regenerators are generally of two major types that are 2R-and 3R-regenerators.…”