一种可传输42个OAM模的光子晶体光纤  

A Type of Photonic Crystal Fiber with 42 OAM Modes

作　　者：杨红红 陈鹤鸣 白秀丽[1] YANG Hong-hong;CHEN He-ming;BAI Xiu-li(School of Optoelectronic Engineering,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;Baer Institute of Excellence,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]南京邮电大学光电工程学院,南京210023 [2]南京邮电大学贝尔英才学院,南京210023

出　　处：《光通信研究》2018年第2期32-35,共4页Study on Optical Communications

基　　金：国家自然科学基金资助项目(61077084;61571237);江苏省自然科学基金资助项目(BK20151509)

摘　　要：文章提出一种可以传输42个轨道角动量(OAM)模式的环形光子晶体光纤,该光纤由中心空气孔、环形高折射率层以及包层构成,其中包层是由方形空气孔与圆形空气孔共同组成。利用有限元法对其进行仿真分析,仿真结果表明,这种结构在1.55μm处可以将简并模间的有效折射率差提高到3.45×10-3,从而大大减小模式间的耦合,所有模式的色散值均较小,例如HE2,1模式的色散只有53.29ps/(nm·km)。此外,光能量主要集中在环形高折射率区域内,且环形区域大小可灵活设计。A new type of ring photonic crystal fiber has proposed which can support 42 Orbital Angular Momentum(OAM)annular modes.The optical fiber is composed of a central air hole,an annular high refractive index layer and a cladding layer,which includes square air holes and circular air holes.We simulate and analyze the mode properties and propagation effects of OAM by finite-element analysis.The simulation results indicate that the mode index difference can be maintained above 3.45×10-3.Therefore,it can effectively reduce the modal coupling in the fiber with small dispersion values for all modes(the dispersion of HE 2,1 is only 53.29 ps/(nm·km)).In addition,the optical energy is mainly concentrated in the high refractive index region,and the annular region does not need additional doping to obtain high refractive index.

关 键 词：轨道角动量 光子晶体光纤 有效折射率 色散 

分 类 号：TN818[电子电信—信息与通信工程]