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Bessel beam

About: Bessel beam is a research topic. Over the lifetime, 1946 publications have been published within this topic receiving 42264 citations.


Papers
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Journal ArticleDOI
TL;DR: In this article, an examination of a direction-variable beam generated by a sound source that causes the decentering operation of the equiamplitude-driven annular array is described.
Abstract: In this paper, we describe an examination of a direction-variable beam generated by a sound source that causes the decentering operation of the equiamplitude-driven annular array. In the presented method, we apply a rounding operation for the width of each annular array element. From results of the calculations carried out for examining the effect on the shape of the radiated sound beams, it is shown that the beam profiles exhibit no marked turbulence in comparison with the profile in which the rounding operation is not applied, as long as the number of array elements and the central radius of the outermost element satisfy the desired value. It is expected that these results will enable the simplification of the process for forming the array element, in the actual production of sound sources.

2 citations

Patent
29 Oct 2015
TL;DR: In this paper, a Bessel beam laser machining apparatus for high aspect ratio hole processing is presented, which is economical and excellently compatible with an existing apparatus by allowing only a simple optical system to be the necessary composition.
Abstract: The present invention aims to provide a Bessel beam laser machining apparatus for a high aspect ratio hole, which allows a micro-shape having a high aspect ratio to be processed with high degree of accuracy by performing laser machining using a Bessel beam. The other aim of the present invention is to provide the Bessel beam laser machining apparatus for processing a high aspect ratio hole, which is economical and excellently compatible with an existing apparatus by allowing only a simple optical system to be the necessary composition to perform high aspect ratio machining.

2 citations

Journal ArticleDOI
TL;DR: In this article, the authors studied the effect of coherent focal domains on the four-wave mixing process of conical laser beams and showed that conical beams have a relatively high degree of coherence for excitation processes.

2 citations

Proceedings ArticleDOI
07 Jul 2019
TL;DR: In this article, a metasurface-based generator for a tilted high-order Bessel beam of order 5 operating in millimeter wave region is presented. And the simulation results apparently prove the reliable generation of the tilted highorder bessel beam by showing correct amplitude and phase profiles.
Abstract: Metasurface is robust in manipulating features of electromagnetic waves by properly designed subwavelength unit cells. Bessel beams and orbital angular momentum (OAM) beams have been investigated extensively for a bunch of applications. High-order Bessel beams that inherently carry OAM may benefit long-distance high-capacity wireless communications. This work presents a metasurface-based generator for a tilted Bessel beam of order 5 operating in millimeter wave region. Unit cells of the metasurface is designed to provide different phase shifts. Phase engineering approach is applied to design the metasurface. The entire metasurface plate is the superposition of four functions and corresponding four sets of phase shifts are combined together to give the final phase distribution of the metasurface. Simulation results apparently prove the reliable generation of the tilted high-order Bessel beam by showing correct amplitude and phase profiles. This work is meaningful for generating novel multifunctional beams utilizing metasurface.

2 citations

Journal ArticleDOI
TL;DR: Simulations presented here show that for breast tissue, which only has about 10% of the absorption of previous criteria, one will still get sidelobes which are comparable to that of a rectangular aperture even when the sidelOBes would be high in a non-absorbing medium.
Abstract: In linear propagation, sidelobe levels of Bessel limited diffraction beams are only about 8 dB down relative to the mainlobe. In the nonlinear regime, these beams will have a region near the source where the side-lobe level of the second harmonic is 16 dB down, but this region has usually been considered to be so small that it is of little practical interest. In this paper it is shown that when there are only 1 to 3 sidelobes in a finite aperture Bessel beam, the second harmonic field will have low sidelobes for distances up to half of the depth of field. This result is backed up by simulations. In a medium with absorption, previous theory has shown that the sidelobes of the Bessel beam will also be reduced but only for absorption that was too high to be of practical use. Simulations presented here show that for breast tissue, which only has about 10% of the absorption of previous criteria, one will still get sidelobes which are comparable to that of a rectangular aperture even when the sidelobes would be high in a non-absorbing medium.

2 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202373
2022149
2021113
2020126
2019134
2018140