新型全固态抗弯曲大模场光子晶体光纤

All-solid bend-resistant large-mode-area photonic crystal fiber

设计了一种对称结构全固态抗弯曲大模场光子晶体光纤，运用全矢量有限元法结合完美匹配层边界条件分析了光纤特性。光纤包层采用正方格子与三角格子相结合的圆孔排布方式，仿真结果显示该光纤具有低弯曲损耗大模场单模特性。仿真优化后，光纤在工作波长1．064μm处，弯曲半径15cm时的弯曲损耗仅为0．053dB／m，弯曲方向角可达±180°；且光纤保持单模工作的可承受弯曲半径为11—17cm，模场面积可达825μm2。该光纤对弯曲不敏感，在高功率光纤激光器、放大器等光通信器件领域具有广泛的发展前景。

An all-solid bend-resistant large-mode-area photonic crystal fiber with symmetrical structure is designed. Fiber properties are analyzed with full vector finite element method combined with matched layer boundary conditions. The cladding of the fiber is combined with square lattice and triangular lattice.Simulation results show that the fiber has the properties of large-mode-area single mode propagation with low bending loss. When the bending radius is 15 cm,bending loss of the fundamental mode is0. 053 d B / m,the bending orientation angle can be extended to ± 180° at a wavelength of 1. 064 μm. Besides,the fiber can keep single-mode operation when the bending radius is between 11 and 17 cm,and the mode field area can reach 825 μm2. The fiber with bending-insensitive characteristics has important applications in optical communication devices,such as high power fiber lasers and amplifiers.