基于NOLM的NRZ信号全光时钟倍频

All-optically doubling clock frequency of NRZ signal based on nonlinear fiber-loop mirror

通过对非线性光纤环形镜(NOLM)透射输出频谱特性的详细研究,发现在一些特定条件下输出频谱中载波谱线会被明显抑制。本文将利用NOLM的这一特性来实现NRZ信号的全光时钟倍频。通过数值仿真对这种方法进行了验证,结果显示,当用同一NRZ信号分束进行适当延迟后作为NOLM的双路泵浦时,输出频谱中出现了增强的信号时钟谱线而载波谱线被抑制。通过FP滤波器提取时钟的系统仿真表明,从透射输出中能够直接提取出倍频时钟信号。

The transmitted spectrum characteristics of nonlinear optical loop mirror （NOLM} are analyzed, It is found that the carrier line of output is clearly restrained under certain conditions. All - optically doubling clock frequency of input NRZ signal is achieved by this feature of NOLM. The methods have been verified through numerical simulation. The results show that the clock components in transmitted spectrum of NOLM is enhanced when NOLM is dual pumped by splitted NRZ signal beam with appropriately delaying, but spectrum line of carrier is restrained. The system simulation incorporated F - P filter demonstrates that the doubled frequency clock pulses can be directly extracted from the corresponding transmitted signal.