Open AccessWavelength conversion of optical 64QAM through FWM in HNLF and its performance optimization by constellation monitoring
Author(s) -
Guo Wei Lu,
Takahide Sakamoto,
Tetsuya Kawanishi
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.000015
Subject(s) - quadrature amplitude modulation , qam , optics , phase shift keying , constellation diagram , phase noise , signal (programming language) , computer science , modulation (music) , optical communication , wavelength , electronic engineering , telecommunications , physics , bit error rate , engineering , acoustics , decoding methods , programming language
All-optical wavelength conversion (AOWC) plays an important role in the future transparent optical networks, in order to enhance the re-configurability and non-blocking capacity. On the other hand, high-order quadrature amplitude modulations (QAMs) have been extensively studied for achieving the high-speed and high-spectral-efficiency optical transmission. Since high-order QAMs are more sensitive to phase and amplitude noise, to implement an AOWC sub-system suitable for high-order QAM signals with minimized power penalty, it is important to optimize the operation conditions in order to avoid extra nonlinear distortions co-existed in the AOWC process. Our experimental results show that, constellation monitoring provides a more intuitive and accurate approach to monitor the converted high-order QAM signals, especially in presence of nonlinear phase noise such as self-phase modulation (SPM). We experimentally demonstrate an AOWC of 64QAM signal through four-wave mixing (FWM) in highly-nonlinear (HNLF). The performance of the AOWC is optimized through the constellation monitoring of the converted signal, achieving a negligible power penalty (<0.3 dB at BER of 10(-3)) for 60-Gbps 64QAM after conversion.