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Collimated beams have attained substantial attention for the past few decades. It mentions to a focused beam that propagates in a medium with little or no angular spread. The generation of such diffraction-free propagation-invariant solutions to the Helmholtz equation was pointed out earlier, demonstrating beams with spatial and temporal invariance traveling over significant distances with no or minimal diffraction. Apart from two unique properties of large non-diffracting range and self-healing/self-reconstruction ability, Bessel beams have shown great prospects in numerous applications like atom guiding, optical tweezers, laser ablation, and laser machining. Alike optical Bessel beams, an acoustic analog named acoustic Bessel beams has also projected significant attention for the past decade. However, Bessel beams in acoustics are still not so broadly applied as in optics, which is related to the lack of convenient techniques of formation of such acoustic waves. Here, we propose a successful generation of a zeroth-order acoustic quasi-Bessel beam using an acoustic axicon. In this article, diffraction-free, self-healing, and scattering resilience properties of a propagating zero-order acoustic Bessel beam under different material properties have been generated and shown by the proposed modified acoustic axicon. After elucidating and validating the Bessel beam generation for different materials, we approach towards achieving the best possible Bessel beam comprising higher amplitude and longer depth-of-field. We portray that our propagating acoustic field preserves an invariant Bessel profile across the transverse XY plane for several hundreds of acoustic wavelengths and provides the analogous self-reconstructions capability manifested by the optical counterpart.
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