非互易旋电材料硅基矩形波导的色散特性研究  

Dispersion characteristics of nonreciprocal gyroelectric silicon-on-insulator rectangular waveguide

作　　者：王慧莹 王智[1,2] 崔粲 李航天 李强 詹翔空[1] 王健 吴重庆[1] Wang Hui-Ying;Wang Zhi;Cui Can;Li Hang-Tian;Li Qiang;Zhan Xiang-Kong;Wang Jian;Wu Chong-Qing(Key Laboratory of Luminescence and Optical Information,Ministry of Education,Institute of Optical Information,School of Science,Beijing Jiaotong University,Beijing 100044,China;State Key Laboratory on Integrated Optoelectronics,Beijing 100083,China)

机构地区：[1]北京交通大学理学院光信息科学与技术研究所,发光与光信息技术教育部重点实验室,北京100044 [2]集成光电子学国家重点联合实验室,北京100083

出　　处：《物理学报》2019年第15期248-253,共6页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61571035);集成光电子学国家重点联合实验室(批准号:IOSKL2018KF22)资助的课题~~

摘　　要：研究设计了基于光通信C波段旋电材料的矩形波导,利用有效折射率法对波导有效折射率及横向电场分布进行求解,得到矩形波导中Emn^x导模的色散方程.研究了在外磁场作用下表面磁等离子体激元的非互易传播特性.还研究了结构参数和材料折射率对非互易色散关系、时延特性的影响.结果表明:其色散曲线随波导宽度的递增逐渐趋向平面波导;群速度vg与波导宽度、传播常数、工作波长相关;矩形波导芯区宽度在140—233.5 nm范围内的波导工艺容差较大;vg与矩形波导y方向包层材料折射率成正相关,当材料为金属银时慢光效应最明显,传输速度最小可以达到2.8×10^–3c.A C-band rectangular waveguide with gyroelectric semiconductor is designed to study the non-reciprocal propagation characteristics of surface magnetoplasmons(SMPs),which are generated by an external magnetic field.The effective refractive index method is used to obtain the effective refractive index and transverse electric field distribution of the waveguide,and a two-dimensional rectangular waveguide is approximately regarded as a combination of two one-dimensional planar waveguides.The dispersion equation of planar waveguide with Emn^x mode in rectangular waveguide is derived.The influences of the structural parameters of rectangular waveguide and the refractive index of material on the non-reciprocal dispersion relation and time-delay characteristics are analyzed by numerical method.Due to the effect of external magnetic field,the off-diagonal elements of dielectric tensor in magnetic photonic crystal are changed.The generation of electrical anisotropy leads the time reversal symmetry to be broken.As a result,the dispersion curves of the rectangular waveguide are asymmetric with respect to propagation constant,and the complete one-way transmission of SMPs can be realized in the asymmetric frequency region.The dispersion curve tends to be a dispersion curve of planar waveguide as the width of rectangular waveguide increases,but the non-reciprocal frequency range is approximately unchanged.The width of the core region and the refractive index of the side material have a significant influence on the non-reciprocal dispersion characteristics:the group velocity of SMPs decreases with w and propagation constant decreasing.The group velocity is related to the waveguide width,propagation constant and the operating wavelength.The relationship between the normalized group velocity and the width of the waveguide separately operating at 1530,1550 and 1565 nm are studied.The group velocity is relatively slow when the width of waveguide’s core region is between 140 nm and 233.5 nm,and the minimum group velocity reaches 5.

关 键 词：矩形波导 有效折射率 表面磁等离子体激元 非互易性 

分 类 号：TB303[一般工业技术—材料科学与工程]