Research on acoustical scattering, optics of bubbles, diffraction catastrophes, and laser generation of sound by bubbles

The research summarized concerns four topics of the propagation and scattering of acoustical and optical waves: (1) acoustical scattering theory and experiments (focused backscattering from elastic spheres due to Rayleigh waves and resonances, Sommerfeld-Watson transformation or predicting echo amplitudes and resonance phenomena, scattering from complicated elastic objects); (2) novel manifestations of diffraction catastrophes and their application to inverse problems (optical hyperbolic-umbilic and cusp diffraction catastrophes in the scattering from a penetrable spheroid, angular location of the cusp as a method of inverse scattering, calculation of the shape of the wavefront which produces a directional cusp diffraction catastrophe); (3) production of sound by a bubble in water illuminated by modulated light (bubbles as a novel photoacoustic source, photoacoustics as a method of investigating adsorbed films or bubbles in water); (4) light scattering from real bubbles in water (optical backscattering from freely rising bubbles in water, the unfolded glory of an oblate bubble, optical effects of adsorbed films.)