基于光子带隙中模式截止特性的单模传输研究

Single-Mode Propagation Based on The Mode Cutting-off Characteristics Within The Photonic Bandgap

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^310 nm when the ratio between fillet diameter and hole diameter increases from 0.2 to 0.8.