Qu Tan, Wu Zhen-Sen, Shang Qing-Chao, Li Zheng-Jun, Bai Lu
J Opt Soc Am A Opt Image Sci Vis. 2013 Aug 1;30(8):1661-9. doi: 10.1364/JOSAA.30.001661.
Electromagnetic scattering of a zero-order Bessel beam by an anisotropic spherical particle in the off-axis configuration is investigated. Based on the spherical vector wave functions, the expansion expression of the zero-order Bessel beam is derived, and its convergence is numerically discussed in detail. Utilizing the tangential continuity of the electromagnetic fields, the expressions of scattering coefficients are given. The effects of the conical angle of the wave vector components of the zero-order Bessel beam, the ratio of the radius of the sphere to the central spot radius of the zero-order Bessel beam, the shift of the beam waist center position along both the x and y axes, the permittivity and permeability tensor elements, and the loss of the sphere on the radar cross section (RCS) are numerically analyzed. It is revealed that the maximum RCS appears in the conical direction or neighboring direction when the sphere is illuminated by a zero-order Bessel beam. Furthermore, the RCS will decrease and the symmetry is broken with the shift of the beam waist center.
研究了零阶贝塞尔光束在离轴配置下被各向异性球形粒子的电磁散射。基于球矢量波函数，推导了零阶贝塞尔光束的展开表达式，并对其收敛性进行了详细的数值讨论。利用电磁场的切向连续性，给出了散射系数的表达式。数值分析了零阶贝塞尔光束波矢量分量的锥角、球体半径与零阶贝塞尔光束中心光斑半径的比值、束腰中心位置沿x轴和y轴的偏移、介电常数和磁导率张量元素以及球体损耗对雷达散射截面（RCS）的影响。结果表明，当球体被零阶贝塞尔光束照射时，最大RCS出现在圆锥方向或相邻方向。此外，随着束腰中心的偏移，RCS将减小且对称性被破坏。
