劈裂纳米矩形的Fano共振效应及对不同偏振角入射激光的衰减作用  

Fano resonance effect of split nano-rectangle and the intensity attenuation of laser with different polarization angles

作　　者：陈万里[1] 冯远明[1] 林旺[1] 

机构地区：[1]天津大学精密仪器与光电子工程学院生物医学工程系,天津300072

出　　处：《光电子．激光》2017年第5期553-559,共7页Journal of Optoelectronics·Laser

基　　金：天津市自然科学基金(14JCYBJC30500)资助项目

摘　　要：利用时域有限差分(FDTD)法模拟了所设计的一种新型劈裂纳米矩形结构消光光谱、近场增强和电荷分布情况。研究了在劈裂金属纳米矩形中,Fano共振形成机理、结构参数对Fano共振峰的影响,以及当入射场偏振方向不同时在红外波长处形成的消光率同等强度骤增现象。研究表明,当改变周围环境折射率时,Fano共振峰有一个非常明显的移动,品质因数FoM可以达到11.8,这种新型劈裂纳米矩形有很好的传感特性。入射光沿不同偏振方向穿过劈裂金属纳米矩形时,在特定红外波长处形成同等强度的消光率增强,对不同偏振角激光强度形成统一衰减的特性使其在混合偏振角激光的强度衰减等光学方面有着重要的应用价值。In the paper,we simulate the extincti on spectra,near field enhancement and charge distribution of the new split nano-rectangle by using the finite difference time domain （FDTD）.Then we investigate the formation mechanism of the Fano resonance in the split m etal nano-rectangle,the effects of structural parameters on Fano resonance peak,the change of the extinction spectra with the incident fields in different polarization directio ns.The results show that Fano resonance peak of the new split nano-rectangle can move obviously when ambient refractive index changes and the FoM can reach 11.8,this shows that the new splitting nano-recta ngle has a good sensing property.The same intensity of extinction rate can be seen in the specific infrared wavelengths wh en the incident light through the split metal nano-rectangleis in different polarization direct ions.The same extinction rate of laser intensity in different polarization directions has impo r tant application on forming uniform homogeneous attenuation for laser with diffe rent polarization angles.

关 键 词：劈裂金属纳米矩形 传感器 Fano共振 消光光谱 激光强度 

分 类 号：TB383.1[一般工业技术—材料科学与工程] O436.2[机械工程—光学工程]