渐变折射率多模光纤中光束自清洁的研究进展  

Research Advances of Beam Self-Cleaning in Graded-Index Multimode Fibers

作　　者：戴佳男 张斌[1,2,3] 侯静[1,2,3] Dai jianan;Zhang Bin;Hou Jing(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,Hunan,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China;Hunan Provincial Key Laboratory of High Energy Laser Technology,National University of Defense Technology,Changsha 410073,Hunan,China)

机构地区：[1]国防科技大学前沿交叉学科科学院,湖南长沙410073 [2]国防科技大学南湖之光实验室,湖南长沙410073 [3]国防科技大学高能激光技术湖南省重点实验室,湖南长沙410073

出　　处：《激光与光电子学进展》2024年第23期100-113,共14页Laser & Optoelectronics Progress

摘　　要：当脉冲峰值功率满足一定条件时会引起渐变折射率多模光纤输出端横向强度分布从散斑向钟形光束转换,这是由多个横模间时空非线性相互作用引起的一种特殊非线性现象,被称为克尔光束自清洁(BSC)。此过程发生时会表现出强烈的模式自净化过程:高阶模式的能量向基模转移,即模式间的能量交换,此时高阶模式的能量不断向基模转移并稳定保存在基模中。其显著的特性是:提高输出光束亮度以及对光纤弯曲和挤压的鲁棒性。这个特点可以打破多模光纤在低输出光束质量方面的限制,使得多模光纤应用前景十分广阔,可用于许多技术应用。本文介绍了此现象从开始发现一直到最近的研究进展,并对其产生机理与解释进行总结。When the peak power of the pulse satisfies certain conditions,it will cause the transverse intensity distribution at the output end of the gradient refractive index multimode fiber to transform from speckle to bell shaped beam.This is a special nonlinear phenomenon caused by the spatiotemporal nonlinear interaction between multiple transverse modes,known as Kerr beam self-cleaning(BSC).When this process occurs,it exhibits a strong mode self purification process:the energy of high-order modes is transferred to the fundamental mode,that is,the energy exchange between modes.At this time,the energy of high-order modes continuously transfers to the fundamental mode and is stably stored in the fundamental mode.Its significant characteristics are:improving the brightness of the output beam and robustness to fiber bending and compression.These features enable us to overcome the limitations of multimode fibers in terms of low output beam quality,which is extremely promising for a host of technological applications.We introduced this phenomenon from its discovery to recent research progress,and summarized its mechanism and explanation.

关 键 词：非线性光纤光学 渐变折射率多模光纤 时空非线性效应 光束自清洁 能量转移 

分 类 号：O436[机械工程—光学工程]