Higher-order harmonics of limited diffraction Bessel beams

We investigate theoretically the nonlinear propagation of the limited diffr action Bessel beam in nonlinear media, under the successive approximation o f the KZK equation. The result shows that the nth-order harmonic of the Bes sel beam, like its fundamental component, is radially limited diffracting, and that the main beamwidth of the nth-order harmonic is exactly 1/n times that of the fundamental. (C) 2000 Acoustical Society of America. [S0001-496 6(00)00503-8].