Wang Leilei, Zeng Jianghui, Zhu Liang, Yang Dandan, Zhang Qian, Zhang Peiqing, Wang Xunsi, Dai Shixun
Appl Opt. 2018 Dec 1;57(34):10044-10050. doi: 10.1364/AO.57.010044.
All-optical switching in long-period fiber grating (LPFG) with Ge-As-Se chalcogenide fibers was proposed. The switching performances at different resonant wavelengths and cladding modes were systematically investigated using coupled-mode theory. By utilizing the ultra-high nonlinearity of chalcogenide glass, the switching power threshold of the proposed LPFG switching at 1.55 μm was 105 MW/cm with power coupling for the low-order LP cladding mode, which was approximately 200 times lower than that of silica LPFG. Furthermore, the temperature stability of the proposed LPFG switching was examined. The optical switching instability due to the laser thermal effect can be well suppressed by optimizing the cladding radius and grating period. Considering the balance between temperature sensitivity and switching power threshold, an all-optical switch with temperature sensitivity of 51 pm/°C was finally realized by selecting the LP mode with a cladding radius of 39 μm.
提出了一种基于锗砷硒硫系光纤长周期光纤光栅（LPFG）的全光开关。利用耦合模理论系统研究了不同谐振波长和包层模式下的开关性能。通过利用硫系玻璃的超高非线性特性，所提出的LPFG在1.55μm波长处针对低阶LP包层模式进行开关时的功率阈值为105MW/cm，这比石英LPFG的功率阈值低约200倍。此外，还研究了所提出的LPFG开关的温度稳定性。通过优化包层半径和光栅周期，可以很好地抑制由激光热效应引起的光开关不稳定性。考虑到温度灵敏度和开关功率阈值之间的平衡，最终通过选择包层半径为39μm的LP模式实现了温度灵敏度为51pm/°C的全光开关。
