光纤通信网中波长选择开关的时频传递性能

为了适应高精度光纤时频传递与光纤通信网融合的发展趋势,对光纤通信网中常用的波长选择开关(WSS)的时频传递性能进行了研究。基于波分复用、单纤双向还回和光学真时延补偿的方案搭建了一套高精度光纤时频传递系统,研究了WSS的输出端口、输出损耗和输入光信号的偏振态变化对时频传递性能的影响,并在此基础上研究了含WSS的时频传递系统的开闭环特性以及闭环情况下WSS的动态切换对时频传递系统的影响。实验结果表明,WSS的引入对光纤时频传递性能的影响是可以控制的,证实了在含WSS的商用光纤通信网中进行高精度时频传递是可行的。     

激光型光纤电流传感器频率的零漂

激光型光纤电流传感器输出的读数是频率之差。首先从理论上分析了无外加电流时频差在零频附近的漂动,分析了法拉第旋转镜(FRM)旋转角偏离90°引起的频率零漂,并指出这是零漂随温度变化的主要原因,提出了克服零漂的具体措施。实验证明了上述分析的正确性和这些措施的有效性,使这种光纤电流传感器在实用化道路上前进了关键的一步。     

Coupled-mode analysis for single-helix chiral fiber gratings with small core-offset

Using conventional coupled-mode theory, a set of coupled-mode equations are formulated for single-helix chiral fiber long-period gratings. A helical-core fiber is analyzed as an example. The analysis is simple in mathematical form and intuitive in physical concept. Based on the analysis, the polarization independence of mode coupling in special fiber gratings is revealed. The transmission characteristics of helical-core fibers are also simulated and discussed.     

Er-doped fiber ring laser gyroscopes operating in continuous waves

A direction related polarizer was inserted into a ring laser cavity to eliminate one of the two eigen-modes as well as spatial hole burning of the gain medium in a bidirectional Er-doped fiber ring laser.Thus,a fiber ring laser gyroscope (FRLG) operating in continuous wave was demonstrated.A beat signal of over 30-dB noise was observed and a good linear relation between the beat frequency shift and cavity rotation rate was obtained.     

可调双频光纤环形腔激光器

提出了一种新型双波长掺铒光纤环形腔激光器.使用可调滤波器改变两束激光的波长差,采用由窄带滤波器和Mach-Zehnder梳状滤波器组成的多重滤波的方式来选择工作频率或者工作模式,有效地抑制相邻纵模之间的跳模现象.利用偏振烧孔效应和激光反向传播的特点大大增强了增益介质的非均匀加宽特性.实验结果表明,得到的单频单纵模双波长激光器的波长间隔可调谐范围为0.019～15 nm;两束激光的拍频信号的频率差调节至472.5 MHz时,在100 Hz～3 GHz范围内只有一个拍频信号.