Bessel beam

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

Laser induced modifications in transparent materials using azimuthally modulated axicon beams

Abstract: Nondiffracting beams are known for their long line of focus, which has various applications in laser materials processing. Zeroth order Bessel beam is usually generated with an axicon and has a distinct circular spatial spectra. The nature of higher order Bessel beams, elliptical and parabolic nondiffracting beams is also conical and their spatial spectra have their own azimuthal modulation. We study numerically and verify experimentally generation of vortical Bessel beams, their superpositions along with elliptical and parabolical beams using an axicon. Laser induced modifications in glasses for various durations and beam powers using generated pulsed beams are analyzed.

Observation of Bessel beams from electric-field-induced patterns on polymer surfaces.

Abstract: We report the observation of Bessel-like beams from periodic patterns induced on viscoelastic polymer surfaces by electric field. The patterns resembling a microaxicon array originate from electrohydrodynamic instabilities in polymer films, where the feature dimensions can be easily controlled. The output beam characteristics from these patterns revealed characteristic traits of Bessel beams.

Generation of Multiple Pseudo Bessel Beams with Accurately Controllable Propagation Directions and High Efficiency Using a Reflective Metasurface

Abstract: In this paper, a generation method procedure based on a reflective metasurface is proposed to generate multiple pseudo Bessel beams with accurately controllable propagation directions and high efficiency. Firstly, by adjusting the miniaturized unit cell of the reflective metasurface to modulate the electromagnetic waves using the proposed method, some off-axis pseudo Bessel beams with different propagation directions are generated. Then, by achieving the large-angle deflection and comparing the results with previous existing methods, the superiority of the proposed method is demonstrated. Based on the generated single off-axis pseudo Bessel beam and the superposition principle of the electromagnetic wave, a reflective metasurface with 47 × 47 elements is designed and fabricated at 10 GHz to generate dual pseudo Bessel beams. Full-wave simulation and experimental measurement results validate that the dual pseudo Bessel beams were generated successfully. The propagation directions of the dual pseudo Bessel beams can be controlled accurately by the reflective metasurface, and the efficiency of the beams is 59.2% at a propagation distance of 400 mm. The energy of the beams keeps concentrating along the propagation axes, which provides a new choice for wireless power transfer and wireless communication with one source to multiple receiving targets.

Coherence radius and integrated scale of degree of coherence of Bessel beam in turbulent atmosphere

Abstract: Coherent properties of the Bessel optical beam formed in turbulent atmosphere are studied The problem analysis is based on the solution of the equation for the transverse second-order mutual coherence function of a field of optical radiation The behaviour of the modulus of the normalized second-order mutual coherence function of a Bessel optical beam depending on parameter of a beam and characteristics of turbulent atmosphere is investigated The behaviour of degree of coherence of a Bessel optical beam depending on parameter of a beam and characteristics of turbulent atmosphere is studied in details It has appeared that at low levels of fluctuations in turbulent atmosphere the degree of coherence of a Bessel optical beam demonstrates oscillating character depending on the difference of the transverse spatial coordinate At high levels of fluctuations in turbulent atmosphere, degree of coherence of a Bessel beam (as it is qualitative, and quantitatively) becomes closer to the similar characteristic of a spherical wave

Extreme Energy Density Confined Inside a Transparent Crystal: Status and Perspectives of Solid-Plasma-Solid Transformations.

Abstract: It was demonstrated during the past decade that an ultra-short intense laser pulse tightly-focused deep inside a transparent dielectric generates an energy density in excess of several MJ/cm3. Such an energy concentration with extremely high heating and fast quenching rates leads to unusual solid-plasma-solid transformation paths, overcoming kinetic barriers to the formation of previously unknown high-pressure material phases, which are preserved in the surrounding pristine crystal. These results were obtained with a pulse of a Gaussian shape in space and in time. Recently, it has been shown that the Bessel-shaped pulse could transform a much larger amount of material and allegedly create even higher energy density than what was achieved with the Gaussian beam (GB) pulses. Here, we present a succinct review of previous results and discuss the possible routes for achieving higher energy density employing the Bessel beam (BB) pulses and take advantage of their unique properties.