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Optical data regeneration is attractive, due to its potential to increase transmission reach and data throughput in communication systems, and several interesting proposals have been made. However, efficient and scalable solutions for regeneration of multiple parallel wavelength channels have been elusive, constituting a key challenge, which must be overcome for optical regeneration to have any prospect of being adapted in actual communication systems. Here we report a scalable wavelength-division multiplexing (WDM) regeneration scheme for phase only regeneration, which satisfies the multichannel requirement, using a set of optical time-lens-based Fourier processors combined with a single phase-sensitive amplifier (PSA). We describe the concept theoretically, and experimentally demonstrate simultaneous regeneration of 16 WDM channels with 50-GHz spacing, each carrying 10-Gbit/s DPSK phase-modulated data. The proposed scheme relies on ultrafast broadband optical processing and is inherently scalable in modulation speed and channel number.

We demonstrate phase-regeneration of phase unlocked OTDM-DPSK serial signals in a single phase sensitive amplifier through optical cross-phase modulation. The BER of an 8×10 Gbit/s OTDM-DPSK signal is improved by 2 orders of magnitude.

QPSK regeneration without active phase stabilization is investigated in numerical simulations. We propose an improved scheme for phase-locking free QPSK regeneration showing significant improvements in the error vector magnitude of the signal.

Simultaneous I and Q extraction for 16-QAM is experimentally demonstrated through field-quadrature decomposition using a polarization-assisted phase sensitive amplifier. The quadrature components are successfully received and performance is evaluated through bit-error-ratio testing.

We propose a scheme for phase regeneration of optical binary phase-shift keying (BPSK) data signals based on phase sensitive amplification without active phase-locking. A delay interferometer (DI) is used to convert a BPSK signal impaired by noise to an amplitude modulated signal followed by cross-phase modulation (XPM) in a highly nonlinear fiber (HNLF) which transfers the data modulation from the amplitude modulated signal to the phase of a locally generated carrier. By placing the HNLF in a loop a stable phase relation is maintained relative to a set of counter propagating locally generated phase-locked pumps. As a result, active phase-stabilization is avoided. A proof-of-principle experiment is carried out with a dual-pump degenerate phase sensitive amplifier (PSA), demonstrating regeneration for a 10 Gb/s non-return-to-zero differential BPSK (NRZ-DPSK) data signal degraded by a sinusoidal phase-noise tone. Receiver sensitivity improvements of 3.5 dB are achieved at a bit-error-rate (BER) of 10-9. Additionally, numerical simulations are performed comparing the idealized regenerator performance in the presence of sinusoidal phase modulation as well as Gaussian phase-noise.

We propose a novel QPSK regenerator scheme based on phase sensitive amplification of a pre-conditioned signal avoiding active phase-locking. Signal pre-conditioning is demonstrated experimentally with error-free (BER < 10-9) performance for a 10-Gbaud QPSK signal.

We propose and demonstrate a novel PSK regenerator based on phase sensitive amplification without active phase-locking. The scheme is applied to regenerate a phase noise degraded 10-Gbit/s DPSK signal, improving receiver sensitivity by 3.5 dB.

We propose a novel all-optical WDM regeneration scheme for DPSK signals based on optical Fourier transformation and phase sensitive amplification. Phase regeneration of a WDM signal consisting of 4x10-Gbit/s phase noise degraded DPSK channels is demonstrated for the first time.