Generation of Bessel Beam from Equiamplitude-Driven Annular Transducer Array Consisting of a Few Elements

Abstract

We present a method for generating a nondiffraction beam using an annular transducer array. In this method, each element is driven with equiamplitude and with an antiphase from its neighboring elements. Theoretical and experimental analyses of an array of this type have been carried out, and the feasibility of this method is confirmed. The beam from a continuous wave is shown using radiated pressure magnitude distributions and it is shown that there exist most suitable values of the width and number of elements. When the array is driven by a burst signal, the beam propagates as a plane wave which has an amplitude corresponding to the zeroth-order Bessel function of the first kind, J 0. Since this beam is realized by an annular array consisting of a few elements, it suggests the possibility of a transducer of this form developing into a source which generates nondiffraction beams.

Effect of decentering ratio of elements in a variable radiation direction sound source on beam profile

“…One proposed method [9,10] uses a concentric annular transducer array, in which each element has a width corresponding to the Bessel function, and which is driven with an antiphase from its neighboring elements with equiamplitude. This method makes the sound source structure much simpler than conventional methods.…”

Underwater Wireless Acousto-Optic Waveguide (UWAOW)

“…In practice, Bessel-like beams with a finite propagation distance were experimentally realised by use of a narrow annular slit, 14,16 or by a conically shaped element (axicon) 17 or by using an annular transducer array. [18][19][20] Thanks to their narrow central core that enhances the lateral resolution and their longer propagation distance respect to conventional Gaussian beams, the applications of these propagation-invariant beams span from medical imaging systems 18 to atom optics.…”

Optimization of a label‐free biosensor vertically characterized based on a periodic lattice of high aspect ratio SU‐8 nano‐pillars with a simplified 2D theoretical model

“…Acoustic Bessel beams have been excited using acoustical axicons (Katchadjian et al, 2010), in analogy to the optical case. However the most convenient way to form acoustic Bessel beams is by using annular transducer arrays (Masuyama et al, 1999). Related theoretical studies include the scattering of Bessel beams by spheres (Marston, 2007b), nondiffracting bulk-acoustic X waves (Salo et al, 1999) or non linearly generated Bessel beams of higher harmonics (Ding et al, 2000a;Cunningham et al, 2000a).…”