超大模场硫系玻璃光子晶体光纤研究进展  

Progress in Chalcogenide Glass Photonic Crystal Fibers with Ultra-Large Mode Area

作　　者：冯宪 杨志勇 施进丹 Feng Xian;Yang Zhiyong;Shi Jindan(Jiangsu Key Laboratory of Advanced Laser Materials and Devices,School of Physics and Electronic Engineering,Jiangsu Normal University,Xuzhou,Jiangsu 221116,China)

机构地区：[1]江苏师范大学物理与电子工程学院,江苏省先进激光材料与器件重点实验室,江苏徐州221116

出　　处：《中国激光》2022年第1期86-100,共15页Chinese Journal of Lasers

基　　金：国家自然科学基金(62175096);江苏省双创团队(中红外光纤激光核心技术,高校创新类2020—2023)。

摘　　要：近年来迅速发展的中红外高功率激光技术迫切需要具有输出光束质量高、质量轻、结构紧凑等特性的中红外光纤介质,用于实现激光产生、传输等。在中红外玻璃中,硫系玻璃具有最宽的透光范围;同时,硫系玻璃又具有最高的折射率和非线性折射率系数,因此它们被认为是理想的产生和传输中红外激光的光纤基质。然而,硫系玻璃网络结构由弱化学键组成,使得硫系玻璃光纤具有较低的激光损伤阈值,这与高功率激光应用需求相矛盾。在不牺牲光纤输出光束质量的前提下,大模场光子晶体光纤技术是优选的实现功率提升的技术方案。本文首先介绍了中红外激光的高功率应用需求和中红外光纤材料低激光损伤阈值之间存在的矛盾,继而对面向中红外高功率激光应用的超大模场硫系玻璃光子晶体光纤的发展进行了综述,详细描述了超大模场硫系玻璃光子晶体光纤设计、制备、材料选择、光纤性能表征等过程,并对其应用前景和存在的技术瓶颈进行了讨论和展望。结果表明,超大模场硫系玻璃光子晶体光纤有望被应用于百瓦级中红外高功率激光应用场景中。Significance Mid-infrared(mid-IR)spectral region contains two important atmospheric windows,i.e.,the midwave infrared window(3-5μm)and the longwave one(8-12μm),where a laser can be transmitted over multiple kilometer along air paths.Furthermore,the vast majority of chemical and biological molecules demonstrate intrinsic fundamental vibration absorptions in the mid-IR domain.High-power mid-IR laser technology has recently advanced rapidly for a variety of applications including remote detection,medical treatment,security,metrology,and highprecision IR spectroscopy.Practically speaking,these applications require components with a minimum power handling capability of 100 W-level.Compact and lightweight mid-IR fiber medium with excellent beam quality is in high demand in a variety of scenarios,including laser generation and power delivery in airborne and spaceborne platforms.Chalcogenide(ChG)glasses have the most transparent spectral range of any mid-IR glass.In comparison with the commonly used fibers whose host materials are silica,tellurite,and fluoride glasses,ChG fiber is the only candidate with a sufficiently low loss of<1 dB/m to cover the most useful 3-5μm window or even a broader range.This is made possible by the weak chemical bonds that make up the ChG glass network.In addition,ChG glass possesses the highest refractive index and nonlinear refractive index in comparison with any other glass materials.As a result,ChG glass has been regarded as an ideal fiber host material for producing and delivering mid-IR lasers.However,due to the glass structure’s weak chemical bonds,ChG has a low laser damage threshold.Hence,a conventional ChG glass fiber with a typical core diameter of 10μm appears unsuitable for mid-IR high-power applications.There have been numerous attempts to break through the mid-IR high-power barrier of ChG fiber usage.First,it has been demonstrated that optimizing the ChG glass composition does not improve the laser damage threshold.This is because it requires the introduction of strong ch

关 键 词：激光光学 光子晶体光纤 红外光纤 超连续谱产生 激光传输 

分 类 号：O436[机械工程—光学工程]