工作波长为2.94µm保偏空芯负曲率光纤  

Polarization-maintaining hollow core negative curvature fiber with an operating wavelength of 2.94µm

作　　者：韩颖[1] 李正然 朱维震 宋朋[2] 周凡迪 杨骐豪 王彦 龚琳 杨慢 王伟[1] 侯蓝田[1] HAN Ying;LI Zheng-Ran;ZHU Wei-Zhen;SONG Peng;ZHOU Fan-Di;YANG Qi-Hao;WANG Yan;GONG Lin;YANG Man;WANG Wei;HOU Lan-Tian(The Key Laboratory for Special Fiber and Fiber Sensor of Hebei Province,Institute of Information Science and Technology,Yanshan University,Qinhuangdao 066004,China;School of Physics and Technology,University of Jinan,Jinan 250022,China)

机构地区：[1]燕山大学信息科学与工程学院河北省特种光纤与光纤传感重点实验室,河北秦皇岛066004 [2]济南大学物理科学与技术学院,山东济南250022

出　　处：《红外与毫米波学报》2020年第6期696-703,共8页Journal of Infrared and Millimeter Waves

基　　金：国家重点研发计划(2019YFB2204001);国家自然科学基金(61405173,61971373);河北省自然科学基金(F2019203549,F2019203440)。

摘　　要：提出一种保偏空芯负曲率光纤,可用于传输工作波长为2.94µm的中红外激光。首先通过调整y方向包层管的厚度和嵌套管到包层管内径的最大距离使y方向偏振模式与包层管表面模式发生微弱耦合,再通过优化纤芯直径和包层管的外径诱导y方向偏振模式与包层管表面模式发生相位匹配,造成y方向偏振模式泄露出纤芯。包层管间的缝隙引导高阶模式泄露出纤芯,而x方向偏振模式因包层管和嵌套管的厚度具有抑制耦合的作用而保持低损耗传输。最终得到一种工作波长为2.94µm的保偏空芯负曲率光纤,x方向偏振模式的限制损耗为2.8×10^-2 dB/m,偏振消光比大于2×10^3,高阶模抑制比大于100,双折射为1.4×10^-5。当光纤y方向弯曲,且半径为25 cm时,弯曲损耗为0.62 dB/m。A polarization-maintaining hollow-core negative curvature fiber is proposed,which can be used to transmit mid-infrared laser with an operating wavelength of 2.94μm.By adjusting the thickness of the cladding tube in the y-direction and the maximum distance from the nested tube to the inner diameter of the cladding tube,the polarization mode in the y-direction is weakly coupled with the surface mode of the cladding tube.By optimizing the core diameter and the outer diameter of the cladding tube,the y-direction polarization mode is strongly coupled with the cladding tube surface mode,causing the y-direction polarization mode to leak out of the core.The gap between the cladding tubes guides the high-order mode to leak out of the core,while the x-direction polarization mode keeps the low confinement loss due to the coupling suppression effect of the thickness of the cladding tube and the nested tube.Finally,a polarization-maintaining hollow core negative curvature fiber with an operating wavelength of 2.94μm is obtained.The confinement loss of the x-direction polarization mode is 2.8×10^-2 dB/m,the polarization extinction ratio is greater than 2×10^3,the high-order mode rejection ratio is greater than 100,and the birefringence is1.4×10^-5.When bending in the y direction with a radius of 25 cm,the bend loss is 0.62 dB/m.

关 键 词：中红外激光 空芯 保偏 负曲率光纤 

分 类 号：TN253[电子电信—物理电子学]