High-speed Multi-channel all-optical de-aggregator based on polarization-assisted phase-sensitive amplification in elastic optical networks

Abstract

An all-optical de-aggregator for four wavelength-multiplexed channels based on polarization-assisted (PA) phase-sensitive amplification (PSA) is proposed, aiming to improve spectral efficiency in elastic optical networks (EONs). Benefiting from a single bi-directional PSA based on the nonlinear-optical loop mirror (NOLM), signals and their conjugates can be extracted and located at two polarization states respectively. To avoid the interference of undesired harmonics sharing the same frequency with input signals, we introduce a spatial dislocation between signal and interference harmonics by sending signals to different input ports of the NOLM. For each channel, the signal and its conjugate are coherently superimposed by PA-PSA. Each of the four 25/50 Gbaud quadrature phase shift keying (QPSK) signals is de-aggregated into two binary phase shift keying (BPSK) signals. We use the same scheme to de-aggregate 25/50 Gbaud 16-ary quadrature amplitude modulation (16-QAM) into 4-level pulse-amplitude-modulation (PAM-4) signals for four channels to verify the tunability of the scheme. The bit-error-rate (BER) and error vector magnitude (EVM) performance of the scheme are investigated and the corresponding OSNRs for error-free signal recovery are obtained respectively.