Lock James A, Laven Philip
Appl Opt. 2017 Jul 1;56(19):G9-G19. doi: 10.1364/AO.56.0000G9.
We consider transmission scattering of a plane wave by a radially inhomogeneous sphere containing a localized region of refractive index decrease. In ray theory, the boundary conditions on the deflection angle at axial and grazing incidence determine that transmission scattering gives rise to an even number of bows, half of them being relative maximum bows and half being relative minimum bows. For a model refractive index profile, we determine the conditions under which different numbers of bows occur, and we suggest physical mechanisms responsible for producing them. We also verify that these bows occur in wave scattering in the short wavelength limit, both in the frequency domain and time domain.
我们考虑平面波被一个包含折射率降低的局部区域的径向非均匀球体的透射散射。在射线理论中,轴向和掠入射时偏转角的边界条件决定了透射散射会产生偶数个弓形,其中一半是相对最大弓形,一半是相对最小弓形。对于一个模型折射率分布,我们确定了出现不同数量弓形的条件,并提出了产生这些弓形的物理机制。我们还验证了这些弓形在短波长极限下的波散射中会在频域和时域中出现。