中红外低损耗大模场空芯反谐振光纤的研究

Research on mid-infrared low-loss large-mode-area hollow core anti-resonant fiber

摘要:

目前传能光纤受限于芯径大小与材料缺陷,在中红外波段难以解决大模场面积与优良传输性能的矛盾。本文提出了一种7管空芯反谐振光纤(hollow core anti-resonant fiber,HC-ARF) ,包层管与外包层以相交的方式连接。利用有限元法结合完美匹配层(perfectly matched layer,PML) 边界条件对光纤进行了数值仿真,综合分析光纤损耗和单模性,得到了光纤参数的优化结果。当纤芯直径为120.0 μm,壁厚为0.7 μm,包层管个数为7个,包层管直径为84.0 μm,外包层半径 为146.9 μm时,该光纤在3.0 μm处损耗为0.004 dB/m,在2.5—3.6 μm波段的损耗低于0.01 dB/m,模场面积达到6 000 μm²,并且具有极好的单模性。提出的空芯反谐振光纤可在保证大模场面积条件下实现低损耗单模传输,在中红外传能等领域具有巨大潜力。

Abstract:

Currently,power delivery fiber is limited by core diameter and material defects,and the conflict between large-mode-area and outstanding transmission performance in the mid-infrared wavelength range is difficult to solve.In this paper,a seven-tube hollow core anti-resonant fiber (HC-ARF) is proposed,in which the cladding tube is connected to the outsourcing layer in an intersecting manner.The fiber is numerically analyzed by the finite element method with perfectly matched layer (PML) boundary conditions,and the optimal results are obtained by comprehensively analyzing fiber loss and single-mode property.When the core diameter is 120.0 μm,the cladding tube thickness is 0.7 μm,the number of cladding tubes is 7,the cladding tube diameter is 84.0 μm and the outsourcing layer radius is 146.9 μm,the fiber loss is 0.004 dB/m at 3.0 μm,and for wavelength range from 2.5 μm to 3.6 μm,the fiber has a loss below 0.01 dB/m,a mode area over 6 000 μm² and excellent single-mode property.The proposed hollow core anti-resonant fiber can achieve low-loss single-mode transmission under large-mode-area conditions,which has great potential in the field of mid-infrared power delivery.