Transient response of the acoustic focusing field

摘要

For the transient focusing field, significant waveform deformation or waveform transition takes place in the vicinity of the focus. It is shown here theoretically and experimentally that the focusing of the transient wave is characterized by the time reversal and the polarity inversion effects between the geometrical wave and the boundary diffration wave. It is also pointed out that these effects are the identical phenomena of wave concentration and phase anomaly of the focusing field for harmonic or monochromatic waves in classical optics and acoustics.