Light scattering by a spheroidal bubble with geometrical optics approximation

This paper proposes the spheroidal model for analyzing the light scattering characteristics of an air bubble. The angular distributions of light scattered by a large spheroidal bubble with end-on incidence are calculated using geometrical optics approximation. The divergence factor, diffraction, and phase shift are considered in the computation. The MATLAB code was developed and verified using the Mie result for a spherical bubble, and the scattering patterns of the two methods agreed well. The effects on the scattering properties are analyzed in terms of the size and shape parameter of the bubble and the incident beam width. The relations between the deviation angle and incident angle, emergent light intensity, and scattering angle are analyzed and used to explain the scattering patterns of a spheroidal bubble.

► We proposed the spheroidal model for analyzing scattering properties of a bubble. ► The complex amplitudes of scattering rays are calculated combined with diffraction. ► The effect of an incident beam width is considered in the calculation. ► The decomposition of the scattering physical process is analyzed.