Theory and acoustic experiments of nondiffracting X-waves (medical US imaging application)

Families of nondiffracting solutions of the isotropic-homogeneous wave equation have been discovered recently by the authors. These families of solutions contain some of the nondiffracting beams known previously, such as the plane wave, Durnin's nondiffracting beams, etc. One subset of the new families of nondiffracting solutions represents waves of X-like shape in a plane through the axis of the waves, which the authors termed X-waves. The theoretical implications of one family of the nondiffracting solutions are reported, and the nondiffracting X-waves with finite apertures are simulated using the Rayleigh-Sommerfeld formulation of diffraction. An acoustic superposition experiment of the nondiffracting X-waves in water was performed to test the theory, and the experiment agrees closely with the theory.<<ETX>>