摘要
基于材料和尺寸不同的三光栅级联结构设计了一种通信波段电磁超材料吸收器。利用时域有限差分法(FDTD)数值分析了结构设计参数对吸收光谱的影响规律,获得了最佳结构。同时探究了吸收光谱对光源特性的依赖性。仿真结果证明,基于表面等离子共振和FP腔共振耦合形成的吸收光谱主要集中在0.66~1.78μm通信波段,吸收率均达94%以上。吸收谱带宽随介质层厚度增大明显展宽;而三光栅宽度比和高度比对吸收带宽几乎无影响,但对吸收率影响较大。因FP腔模和SPR模两种共振机制在同一单元周期下,共振波长沿相反方向漂移,近乎彼此抵消,导致吸收光谱带宽对周期不敏感;同时具有吸收光谱特性不受光源入射角限制的优势。
With the development of communication technology,adaptive optical absorber with broadband and high response band has become the focus of attentions and research at home and abroad.A communication band electromagnetic metamaterial absorber is designed based on three-grating cascade structure of different material and size.The influence of structural design parameters on absorption spectrum is numerically analyzed by FDTD,and the optimal structure is obtained.The simulation results show that the absorption spectrum based on surface plasmon resonance and FP cavity resonance is mainly concentrated in the communication band of 0.66~1.78μm,and the absorption rate is above 94%.The bandwidth of ultra-high absorption spectrum is obviously broadened with the increase in the thickness of the dielectric layer.The three-grating width ratio and height ratio has no effect on the absorption bandwidth,but has a great effect on the absorption rate.Because FP cavity mode and SPP mode,these two resonance mechanisms are in the same cell cycle,the resonance wavelength along the opposite direction of the drift,almost cancels each other.As a result,the absorption spectrum bandwidth is not sensitive to the period.The absorber has the advantages of simple structure,small size,easily integration with chip,adjustable absorption wavelength,wide bandwidth and insensitive to incident angle of light source.It has potential application in the fields of broadband optical communication,photovoltaic power generation and optical detection.
作者
金文最
赵洪霞
安雪瑶
黄淑盈
JIN Wen-zui;ZHAO Hong-xia;AN Xue-yao;HUANG Shu-ying(Electronic and Information Engineering College,Ninglx?University of Technology,Ningbo,315O16 China)
出处
《光电子．激光》
EI
CAS
CSCD
北大核心
2020年第8期800-805,共6页
Journal of Optoelectronics·Laser
基金
国家自然科学基金(61605097)
浙江省基础公益研究计划项目(LGC19F050001,LGC20F050001)
宁波市自然科学基金(2019A610081)资助项目。
关键词
吸收器
通信波段
带宽
吸收率
absorber
communication band
bandwidth
absorptivity
