摘要
设计了一种基于硅基波导光子轨道角动量的产生及复用器,该器件主要由非对称定向耦合器和带沟槽的波导两部分组成.根据相位匹配条件,基模TE 00通过非对称定向耦合器耦合成一阶模TE 10,带沟槽的波导可支持光轴相对于水平和垂直方向旋转45°的两个正交的本征模,调整两个正交的本征模的相位差,使其进行简并,可进一步将TE 10转换为多种轨道角动量模式,并在第二个沟槽结构中进行复用.采用时域有限差分法进行仿真计算,结果表明:该器件可以实现拓扑荷为+1、0、-1的光子轨道角动量模式的产生及复用,且器件结构紧凑,尺寸小于80μm×5.3μm,损耗小于0.24 dB,适用波长范围为1.47~1.58μm.该器件制作工艺简单,易于集成,可应用于轨道角动量复用系统等领域.
Based on an integrated silicon platform,a device for generating and multiplexing optical orbital angular momentum modes is proposed,which is consisted of asymmetric directional coupler and trench waveguides.According to the principle of phase matching,the fundamental mode TE 00 is coupled to the first-order mode via an asymmetric directional coupler.Single-trench waveguide can support two orthogonal linear polarization-like modes whose optical axes are rotated by around 45°with respect to the horizontal and vertical directions.Adjusting the phase difference of two orthogonal eigenmodes to make them degenerate,TE 00 can be converted into orbital angular momentum modes with various topological charges,and multiplexed in the second trench.The simulation is carried out with finite difference domain method.The results show that the device can realize the generation and multiplex of orbital angular momentum modes with topological charges of+1,0,-1.The proposed device is very compact with a footprint of<80μm×5.3μm and an insertion loss of 0.24 dB,and is fit for a wavelength range from 1.47μm to 1.58μm.The structure is simple and easy to integrate,having a good application in orbital angular momentum multiplexing system.
作者
曹恒颖
陈鹤鸣
白秀丽
CAO Heng-ying;CHEN He-ming;BAI Xiu-li(College of Electronic and Optical Engineering&College of Microelectronics,Nanjing University of Posts and Telecommunications,Nanjing 210023,China;Bell Honors School,Nanjing University of Posts and Telecommunications,Nanjing 210023,China)
出处
《光子学报》
EI
CAS
CSCD
北大核心
2019年第12期15-22,共8页
Acta Photonica Sinica
基金
国家自然科学基金(Nos.61077084,61571237)
江苏省自然科学基金(No.BK20151509)
江苏省研究生科研创新计划(No.KYLX15_0835)~~
关键词
光通信
轨道角动量
轨道角动量多路复用
时域有限差分法
硅基波导
相位匹配
模式耦合
Optical communication
Orbital angular momentum modes
Orbital angular momentum modes multiplex
Finite difference time domain method
Silicon waveguides
Phase matching
Mode coupling
