空芯光子带隙光纤拥有优越的环境适应性, 但光纤中的高阶模使其在多种场合下的应用受到制约。利用光子带隙内高阶模式在小于截止波长时被强烈抑制, 而基模在该波段可以稳定存在的特性, 提出了实现单模传输的方法, 并通过实验验证了该方法的可行性。在此基础上仿真分析了包层参数对单模传输波段的影响, 计算结果表明, 单模传输波段的带宽随材料折射率的增加而增加, 折射率由1.445提高到2时, 带宽增加2.9倍; 相对倒角由0.2提高到0.8时, 单模传输波段的工作波长移动310nm以上。

Hollowcore photonic bandgap fiber (HCPBF) has excellent environment adaptability, but highorder modes (HOMs) in HCPBF limit its applications in many areas. A method for singlemode propagation is proposed, which is based on the phenomenon that the HOMs are seriously suppressed and the fundamental modes stably exist when the operating wavelength is less than the cutoff wavelength. The method is experimentally verified. The influence of HCPBF cladding structure parameters on the bandwidth and operating wavelength for singlemode operation is simulated. The results show that the singlemode bandwidth is broadened by ~2.9 times when the index increases from 1.445 to 2, and singlemode operating wavelength can move ~310nm when the ratio between fillet diameter and hole diameter increases from 0.2 to 0.8.