Light Scattering from Bubbles in Liquids.

The scattering of laser light from bubbles in liquids was photographed, and angular features in the far -zone intensity are compared with models. Diffraction effects are prominent in three regions of the scattering: near the critical angle, and in the forward and backward directions. The forward and backward scattered light exhibits the intensity enhancement known as the glory. Simple geometrical optics is unable to approximate the scattering pattern in the diffraction regions. Physical-optics models are presented for each case and shown to be in agreement with the observations. These models give insight into the optical properties of scatterers whose refractive index is less than that of their surroundings. Comparisons also include the results of Mie theory computations for the critical-angle and forward regions. Some applications of the results to the sizing and detection of bubbles are discussed.