分析并实验验证了一种全光纤锁模激光器结构的全光时钟提取方案。方案中，采用高非线性光纤(HNLF)替代传统结构中的半导体光放大器(SOA)，利用光纤中的交叉相位调制(XPM)效应实现腔内的非线性调制，避免了以SOA作为非线性光调制器件的锁模激光器全光时钟提取方案中，由于载流子恢复时间较长从而限制工作速率的缺点，以达到突破“电子瓶颈”的目的。理论分析了光纤中交叉相位调制的特性以及环形锁模腔的时钟提取原理，并通过实验，从40 Gbit/s的光归零码(RZ)信号中提取出了高质量的光信号时钟。该方案可以直接在更高速率条件下工作。

A scheme of all-optical clock recovery based on an all optical fiber mode-locking cavity configuration is analyzed and demonstrated. In the scheme, the semiconductor optical amplifier (SOA) in traditional structures is displaced by a segment of highly nonlinear optical fiber (HNLF). Through the cross-phase modulation effect (XPM) in optical fiber, the nonlinear modulation is implemented in the cavity, which is able to overcome the limitation of date rate caused by the carrier recovery time of SOA in traditional methods and break through the "electronics bottleneck". The theory of cross phase modulation effect in optical fiber and the principle of clock recovery in mode-locking ring cavity are analyzed. In addition, a high quality clock signal is successfully extracted from a 40 Gbit/s optical return-to-zero (RZ) signal experimentally. This scheme can work straightway with higher bit rate.