Impact of phase to amplitude noise conversion in coherent optical systems with digital dispersion compensation.

The impact of phase to amplitude noise conversion for QPSK, 16-QAM, and 64-QAM coherent optical systems are investigated with electronically-compensated chromatic dispersion (CD). The electronic equalizer is shown to convert the phase noise from the local oscillator (LO) to amplitude noise, limiting the amount of CD that can ideally be compensated digitally. The simulation results demonstrate that the performance of coherent systems can significantly be degraded with digitally compensated CD and LO phase noise. The maximum tolerable LO linewidth is also investigated for the different modulation formats and found to become increasingly stringent for longer transmission distance and higher symbol rate.

[1]  J. Kahn,et al.  Feedforward Carrier Recovery for Coherent Optical Communications , 2007, Journal of Lightwave Technology.

[2]  Alan Pak Tao Lau,et al.  Coherent detection in optical fiber systems. , 2008, Optics express.

[3]  S. Savory,et al.  Electronic compensation of chromatic dispersion using a digital coherent receiver. , 2007, Optics express.

[4]  J. Kahn,et al.  Digital Equalization of Chromatic Dispersion and Polarization Mode Dispersion , 2007, Journal of Lightwave Technology.

[5]  William Shieh,et al.  Equalization-enhanced phase noise for coherent-detection systems using electronic digital signal processing. , 2008, Optics express.

[6]  S. Savory,et al.  Laser Linewidth Tolerance for 16-QAM Coherent Optical Systems Using QPSK Partitioning , 2010, IEEE Photonics Technology Letters.

[7]  M. O'Sullivan,et al.  WDM Performance and PMD Tolerance of a Coherent 40-Gbit/s Dual-Polarization QPSK Transceiver , 2008, Journal of Lightwave Technology.

[8]  R. Noe,et al.  Hardware-Efficient Coherent Digital Receiver Concept With Feedforward Carrier Recovery for $M$ -QAM Constellations , 2009, Journal of Lightwave Technology.

[9]  Bingkun Zhou,et al.  Numerical Study of Lumped Dispersion Compensation for 40-Gb/s Return-to-Zero Differential Phase-Shift Keying Transmission , 2007, IEEE Photonics Technology Letters.

[10]  Kuang-Tsan Wu,et al.  Real-time measurements of a 40 Gb/s coherent system. , 2008, Optics express.

[11]  L.G. Kazovsky,et al.  Homodyne Phase-Shift-Keying Systems: Past Challenges and Future Opportunities , 2006, Journal of Lightwave Technology.

[12]  R. Noe,et al.  Phase noise-tolerant synchronous QPSK/BPSK baseband-type intradyne receiver concept with feedforward carrier recovery , 2005, Journal of Lightwave Technology.

[13]  Seb J Savory,et al.  Digital filters for coherent optical receivers. , 2008, Optics express.

[14]  Chongjin Xie,et al.  WDM coherent PDM-QPSK systems with and without inline optical dispersion compensation. , 2009, Optics express.

[15]  J. Kahn,et al.  Compensation of Dispersion and Nonlinear Impairments Using Digital Backpropagation , 2008, Journal of Lightwave Technology.