Optical analysis of nanoparticles via enhanced backscattering facilitated by 3-D photonic nanojets

被引:312
作者
Li, X [1 ]
Chen, ZG
Taflove, A
Backman, V
机构
[1] Northwestern Univ, Dept Biomed Engn, Evanston, IL 60208 USA
[2] Northwestern Univ, Dept Elect & Comp Engn, Evanston, IL 60208 USA
来源
OPTICS EXPRESS | 2005年 / 13卷 / 02期
关键词
D O I
10.1364/OPEX.13.000526
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We report the phenomenon of ultra-enhanced backscattering of visible light by nanoparticles facilitated by the 3-D photonic nanojet - a sub-diffraction light beam appearing at the shadow side of a plane-wave-illuminated dielectric microsphere. Our rigorous numerical simulations show that backscattering intensity of nanoparticles can be enhanced up to eight orders of magnitude when locating in the nanojet. As a result, the enhanced backscattering from a nanoparticle with diameter on the order of 10 nm is well above the background signal generated by the dielectric microsphere itself. We also report that nanojet-enhanced backscattering is extremely sensitive to the size of the nanoparticle, permitting in principle resolving sub-nanometer size differences using visible light. Finally, we show how the position of a nanoparticle could be determined with subdiffractional accuracy by recording the angular distribution of the backscattered light. These properties of photonic nanojets promise to make this phenomenon a useful tool for optically detecting, differentiating, and sorting nanoparticles. (C) 2005 Optical Society of America.
引用
收藏
页码:526 / 533
页数:8
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