40Gb/s信号的全光3R再生

40 Gb/s All-Optical 3R Regeneration

研制出以注入锁模光纤激光器进行时钟恢复、电吸收调制器(EAM)作光判决门进行信号再整形的新型全光3R再生器,成功地运行于40 Gb/s。理论和实验证明锁模环形激光器腔内放置的可调谐光滤波器的透射谱形状对时钟的脉宽有显著影响,超高斯透射谱的光滤波器利于获得窄时钟光脉冲,腔内放置这样的滤波器使恢复的时钟光脉冲谱宽达0.44 nm、脉宽6 ps、时间抖动小于1 ps。最佳选择用作光判决的开关门的参量,改善了开关门的传输函数,使其接近阶跃函数,并使得开关窗宽度达到最佳。对于被剩余色散恶化的40 Gb/s归零码信号进行了3R再生,再生后达到了无误码。

A novel 40 Gb/s 3R regenerator was proposed and demonstrated based on two-ring injection mode-locked fiber laser as the clock recovery and electroabsorption modulator as the reshaping optical gate. The effect of the shape of the transmission spectrum of the optical filter on the output pulses of actively mode locked fiber ring laser has been studied experimentally and numerically. It was found that, with the same 3 dB bandwidth, the filter which had a super-Gaussian profile tended to generate narrow pulses. With this scheme, an optical clock pulse train with a spectrum bandwidth of 0.44 nm, a pulse-width of about 6 ps and a timing jitter of 〈 1 ps was recovered. The transmission function of optical gate was improved by optimizing the design of parameters to approach the step function. The width of the switching window was also optimized. With this regenerator, error-free 3R regeneration was performed from 40 Gb/s RZ signal that was degraded by residual dispersion.