用非线性光纤连接的长周期光栅对的光开关特性

Optical Switching in a Nonlinear-Fiber Connected Long-Period Fiber Grating Pair

提出用一根掺铒光纤连接两个对称的长周期光纤光栅(EDF-LPFG)对构成的新型全光开关。数值模拟了在交叉相位调制下对应于不同抽运功率的信号光的透射谱;还研究了在不同光栅的有效折射率调制幅度和光纤吸收系数下,信号光透射率随抽运光功率的变化。导出了器件的阈值开关功率公式。EDF-LPFG对光开关的阈值开关功率比单LPFG光开关的开关功率降低了5个数量级,不到25 mW。

A new all-optical switching device, which is constructed by connecting an erbium-doped fiber with two symmetrical long-period fiber gratings （EDF-LPFG） pair was proposed. The transmission spectra of signal light for different pump powers in cross-phase modulation are simulated, and the transmissions of signal light as a function of the pump power under different effective index change and absorption coefficients are also discussed. The formula for threshold switching power of EDF-LPFG pair switch is derived. Compared with the single LPFG switch, the threshold switching power of EDF-LPFG pair switch is dramatically reduced by 5 orders, less than 25 mW. Such kind all-optical switch is hopeful to be used in future all-optical communication.