Title :
A DSP-Based Control Method For a Nonlinear Mach–Zehnder Interferometer DPSK Regenerator
Author :
Shu Zhang ; Cartledge, John C.
Author_Institution :
Dept. of Electr. & Comput. Eng., Queen´s Univ., Kingston, ON, Canada
Abstract :
A frequency offset and phase control method is described for a differential-phase-shift-keying (DPSK) 2R (reamplification and reshaping) regenerator based on a nonlinear Mach-Zehnder interferometer. The controller is comprised of a coherent receiver, analog-to-digital converters (ADCs), a digital signal processor, and an optical frequency/phase shifter. For a 40 Gb/s DPSK signal, simulation results demonstrate that an ADC sampling rate of only 335.94 MSa/s is needed to adequately estimate the frequency offset and phase noise, and adjust the pump signal accordingly. The cascadability of the 2R regenerator is evaluated in recirculating loop simulations for different regenerator spacings, using both ideal DPSK signals and captured experimental DPSK signals. The influence of residual span dispersion on the performance is investigated.
Keywords :
Mach-Zehnder interferometers; analogue-digital conversion; differential phase shift keying; nonlinear optics; optical information processing; optical phase shifters; optical pumping; optical receivers; phase noise; ADC sampling rate; DPSK signals; DSP-based control method; analog-to-digital converter; bit rate 40 Gbit/s; coherent receiver; differential-phase-shift-keying 2R regenerator; digital signal processor; frequency offset; nonlinear Mach-Zehnder interferometer DPSK regenerator; optical frequency shifter; phase control method; phase noise; phase shifter; pump signal; reamplification and reshaping; recirculating loop simulations; regenerator spacings; residual span dispersion; Differential phase shift keying; Frequency estimation; Optical attenuators; Optical noise; Phase noise; Repeaters; Signal to noise ratio; Differential phase-shift keying (DPSK); Optical regeneration; differential phase-shift keying (DPSK); optical regeneration; phase sensitive amplification;
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2015.2433176
