轴棱锥线聚焦特性对成像系统焦深的影响

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。

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

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.