基于F-P腔和SOA 100 GHz及200 GHz全光时钟恢复

100 GHz and 200 GHz All-Optical Clock Recovery Based on F-P Cavity and SOA

解释了当信号速率是法布里-珀罗(F-P)腔的自由光谱区宽度(FSR)的整数倍时,利用F-P腔和基于半导体光放大器(SOA)级联偏移滤波的幅度均衡系统实现全光时钟恢复的原理。从理论上研究了幅度均衡系统中偏移滤波参数对时钟幅度抖动的影响,并且给出了理论上最佳的偏移滤波参数。实验中,为了解决时分复用(OTDM)系统中不同时隙信道信号光相位不同导致F-P腔输出光脉冲幅度严重起伏的问题,采用了对信号光进行波长转换的方法,最终利用FSR为102 GHz的F-P腔和幅度均衡系统成功地分别从102 Gb/s和204 Gb/s归零码开关键控(RZ-OOK)码信号中恢复出了102 GHz和204 GHz的光时钟。其中102 GHz时钟的幅度抖动为8.5%,时间抖动小于236 fs;204 GHz时钟的幅度抖动为9.4%,时间抖动小于251 fs。

The principle, how the Fabry-P6rot （F-P） cavity followed by amplitude equalizing system based on semiconductor optical amplifier （SOA） and cascade offset filter achieves all-optical clock recovery from the signal whose bit rate is a multiple of the free spectral range （FSR） of the F-P cavity, is explained. How the parameter of the filter in the amplitude equalizing system affects the amplitude fluctuation of the recovered clock is researched and the best parameter in theory is obtained. In the experiment, to solve the problem that is great fluctuation after F-P cavity because of the phase difference between the optical signals in different channels of the optical time division multiplexed （OTDM） system, a wavelength conversion system is utilized. Finally, by using the F-P cavity with 102 GHz FSR and amplitude equalizing system, 102 GHz optical clock recovery from 102 Gb/s return to zero code on-off Keying （RZ-OOK） signal and 204 GHz optical clock recovery from 204 Gb/s RZ-OOK signal are experimentally demonstrated. The 102 GHz recovered clock has an amplitude fluctuation of 8.5% and a timing jitter less than 236 fs, and the 204 GHz recovered clock has an amplitude fluctuation of 9.4% and a timing jitter less than 251 fs.