Fini John M
Opt Express. 2006 Jan 9;14(1):69-81. doi: 10.1364/opex.14.000069.
Achieving very large mode area is a key goal in current research on microstructure and solid fibers for high power amplifiers and lasers. One particular design regime of recent interest has effective area over 1000 square microns and has effectively-single-mode operation ensured by bend losses of the higher-order modes. Simulations show that these fibers are extremely prone to bend-induced distortion and reduction in mode area. The calculated area reduction would significantly impact nonlinear impairments for bend radii relevant to any reasonable spooled package, and can be over 50 percent for bend radii tighter than 10cm. The parabolic-profile design has a natural immunity to bend-induced mode distortion and contraction, and shows superior performance in simulated fair comparisons with other fiber families, including microstructure fibers.
实现超大模面积是当前高功率放大器和激光器的微结构与固体光纤研究中的一个关键目标。近期受到关注的一种特定设计方案具有超过1000平方微米的有效面积，并且通过高阶模的弯曲损耗确保了有效单模运行。模拟结果表明，这些光纤极易受到弯曲引起的畸变和模面积减小的影响。计算得出的面积减小对于与任何合理的盘绕封装相关的弯曲半径而言，会显著影响非线性损伤，并且对于小于10厘米的弯曲半径，面积减小可能超过50%。抛物线型剖面设计对弯曲引起的模式畸变和收缩具有天然的抗性，并且在与其他光纤类别（包括微结构光纤）的模拟对比中表现出卓越的性能。
