抄録
The harmonic components of finite-amplitude focused sounds emitted from a Gaussian source is examined by theory and experiments. Assuming that the radial distributions of amplitude and phase for each harmonic component are independent of the excitation level, the simplified equations for Fourier coefficients to express the distorted sound are derived. The equations were numerically solved by finite difference method to get the amplitudes and phases of harmonic components. The waveform was observed at different positions in the focused Gaussian beam realized by a circular concave piezo electrictransducer with a back electrode fabricated in the shape of star. The experi mentalresults for the first four harmonic components agreed well with the computed results. The present computation is convenient for analyzing the finite-amplitude focused Gaussian beam.
