中国激光, 2014, 41(11): 1105010, 网络出版: 2014-11-01

速率可变差分相移键控非归零码信号的全光时钟提取

All-Optical Clock Recovery of Variable Bit-Rate Non-Return-to-Zero Differental Phase Shift Keying Signal
作者单位

1北京交通大学光信息科学与技术研究所, 北京 100044

2发光与光信息技术教育部重点实验室, 北京 100044

摘要
全光再放大、再定时、再整形(3R)技术是未来全光通信网络的发展方向,全光时钟提取是全光3R技术的关键技术之一。随着新型相位调制格式信号的广泛应用,对新型相位调制格式信号的全光时钟提取研究引起了越来越多的关注。基于此,提出了一种基于可调谐解调器的速率可变差分相移键控非归零码(NRZ-DPSK)信号的时钟提取方法。采用自由空间光的斐索干涉仪构成可调谐解调器,将NRZ-DPSK信号转换为含有时钟分量的归零码(RZ)强度信号,调谐范围可覆盖2.5~40 Gb/s。将解调出的RZ信号注入到光纤环形激光器实现了5 Gb/s的长度为27-1的伪随机码NRZ-DPSK信号的全光时钟提取,其消光比高于10 dB。
Abstract
All-optical 3R (reampifying, retiming, reshaping) technique is the trend of the all-optical communication network and all-optical clock recovery is one of the key techniques of all-optical 3R technique. With the application of new phase modulation format, the research of all-optical clock recovery of new phase modulation format is attracting more and more attention. A new scheme of clock recovery of variable bit-rate non-return-to-zero differential phase shift keying (NRZ-DPSK) signal based on tunable demodulator is proposed. The tunable demodulator composed by Fizeau interferometer based on free space light converts the NRZ-DPSK signal into return-to-zero (RZ) signal which includes clock component. The demodulator can demodulate 2.5 Gb/s to 40 Gb/s NRZ-DSPK signal. The demodulated RZ signal is injected into the fiber loop laser and all-optical clock recovery from the length of 27-1 pseudo-random bit sequence (PRBS) NRZ-DPSK signal is realized. The extinction rate of the recovered clock is higher than 10 dB.
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