Optical Predistortion Enabling Phase Preservation in Optical Signal Processing Demonstrated in FWM-Based Amplitude Limiter

Kyle R. H. Bottrill, Francesca Parmigiani, David J. Richardson, Periklis Petropoulos
2017 Journal of Lightwave Technology  
We propose and demonstrate a technique to obtain phase preservation in optical processing which is suitable for many four-wave mixing (FWM) based processing devices, provided they may be modified to incorporate two conjugating FWM stages. It functions by using a first conjugating nonlinear stage to predistort the signal using self-phase modulation (SPM) such that when the signal undergoes further SPM in a second conjugating FWM stage, the two SPM contributions negate each other, resulting in
more » ... se preserving output. In this work, we use the second stage to perform amplitude squeezing through parametric gain saturation and characterise the scheme by regenerating a QPSK signal contaminated with broadband amplitude noise. Experimental analysis of the system with and without predistortion is provided and phase preserving operation using the proposed scheme is confirmed.
doi:10.1109/jlt.2016.2604493 fatcat:kb5zm6puwnhe3gmhgdckys5hxa