Saha Sudipta, Singh Ankit K, Ray Subir K, Banerjee Ayan, Gupta Subhasish Dutta, Ghosh Nirmalya
Opt Lett. 2016 Oct 1;41(19):4499-4502. doi: 10.1364/OL.41.004499.
We study the near field to the far field evolution of spin angular momentum (SAM) density and the Poynting vector of the scattered waves from spherical scatterers. The results show that at the near field, the SAM density and the Poynting vector are dominated by their transverse components. While the former (transverse SAM) is independent of the helicity of the incident circular polarization state, the latter (transverse Poynting vector) depends upon the polarization state. It is further demonstrated that the interference of the transverse electric and transverse magnetic scattering modes enhances both the magnitudes and the spatial extent of the transverse SAM and the transverse momentum components.
我们研究了自旋角动量(SAM)密度从近场到远场的演化以及球形散射体散射波的坡印廷矢量。结果表明,在近场中,SAM密度和坡印廷矢量主要由它们的横向分量主导。虽然前者(横向SAM)与入射圆偏振态的螺旋度无关,但后者(横向坡印廷矢量)取决于偏振态。进一步证明,横向电散射模式和横向磁散射模式的干涉增强了横向SAM和横向动量分量的大小和空间范围。