Abstract:
Freely rising gas bubbles in seawater illuminated by sunlight exhibit colors [P. L. Marston, Appl. Opt. 30, 3479--3484 (1991)] in the angular region of the transition to total reflection. Light scattering calculations and experiments [D. S. Langley and P. L. Marston, Appl. Opt. 23, 1044--1045 (1984); W. P. Arnott and P. L. Marston, J. Opt. Soc. Am. A 5, 495--506 (1988)] are relevant both to visual properties and to scattering devices to monitor bubble population and single-bubble dynamics. In addition to critical angle scattering, glory-enhanced backscattering and Brewster-angle polarization have been observed. Some shape effects have been studied and some effects of surface coatings have been calculated [Marston et al., Proc. SPIE 925, 308--316 (1988)]. Applications to measuring some of the effects of surfactants on the dynamics of single bubbles [Asaki et al., Phys. Rev. Lett. 75, 2686--2689 (1995); 75, 4336(E) (1995)] will also be discussed. [Work supported by the Office of Naval Research.]