光子晶体光纤接续损耗的理论分析

基于超格子构造法,采用全矢量模型计算了光子晶体光纤的模场半径,由此出发理论分析了光子晶体光纤与普通单模光纤之间接续损耗分别受横向偏移、轴向倾斜以及模场不匹配的影响,给出了光子晶体光纤在部分常用结构参量区域{Λ,d/Λ}内与SMF-28接续损耗的理论值,讨论了光子晶体光纤各结构参量与接续损耗之间的关系。并简要分析了不同结构光子晶体光纤之间的接续损耗。结果表明,接续损耗对横向偏移和轴向倾斜都非常敏感;孔距是决定接续损耗大小最主要的因素;与普通单模光纤接续,当光子晶体光纤的孔距比该单模光纤纤芯半径大一些时,接续损耗比较小;两种不同结构光子晶体光纤之间的接续损耗大小最主要取决于它们孔距的差异。

Theoretical Analysis on Splice Loss of Photonic Crystal Fibers

Based on the supercell overlapping method, the full vector model is adopted to compute the mode field radius of photonic crystal fibers (PCF). And then, the splice losses of PCF-single model fiber (SMF) under the influence of transverse offset, angular misalignment and mode field mismatch are analyzed, respectively. The theoretical values of PCF-SMF-28 in some conventional ranges of structural parameters {Λ, d/Λ} are offered, and the effect of each structure parameter on the splice loss is discussed. The splice loss between two PCFs with different structures is analyzed in brief. It is concluded that the splice loss is very sensitive to transverse offset and angular misalignment, the most important structural parameter effecting splice loss is the pitch, Λ, of PCF, the splice loss of PCF-SMF is relatively low if the pitch of PCF is larger than the radius of SMF core, and the splice loss between two PCFs with different structures is mainly decided by the difference between their pitches.