Bessel beam

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

High-Resolution Underwater Single-Photon Imaging With Bessel Beam Illumination

Abstract: The ability to achieve precise underwater 3D imaging is an urgent need in marine research and development. Yet, due to the strong scattering by the water, the laser beam is easily spread out in the underwater propagation, which hampers the imaging quality with low resolution. In this paper, we demonstrate a single-photon LiDAR with Bessel beam illumination, which central spot shows a stable diameter of about 0.73 mm after propagating 18 m in water. Together with a single-photon detector to sense the weak returning laser echoes, the transverse resolution reaches about a few millimeters at 17.5 m in water. In the experiment, an underwater optical image of 103.1 mm × 192.1 mm with 516 × 97 pixels is reconstructed. The result shows that our single-photon LiDAR with Bessel beam illumination greatly improves the imaging resolution in the long distance underwater sensing.

Femtosecond Bessel-beam-assisted high-aspect-ratio microgroove fabrication in fused silica

Abstract: A simple and repeatable method to fabricate high-aspect-ratio (HAR) and high-quality microgrooves in silica is reported. The method consists of two steps: (1) formation of laser-modified regions by femtosecond Bessel beam irradiation, and (2) removing laser-modified regions through HF etching. Uniform, straight microgrooves can be fabricated and the highest aspect ratio that can be reached is ～52. The phenomenon is attributed to the uniform energy distribution in the long propagation distance, which leads to the long and uniform laser-modified regions and subsequent HF acid etching of laser-modified regions with high selectivity. This method will have potential applications in fabrication of HAR microgrooves in transparent materials.

WGM resonators for studying orbital angular momentum of a photon, and methods

Abstract: An optical system, device, and method that are capable of generating high-order Bessel beams and determining the orbital angular momentum of at least one of the photons of a Bessel beam are provided The optical system and device include a tapered waveguide having an outer surface defined by a diameter that varies along a longitudinal axis of the waveguide from a first end to an opposing second end The optical system and device include a resonator that is arranged in optical communication with the first end of the tapered waveguide such that an evanescent field emitted from (i) the waveguide can be coupled with the resonator, or (ii) the resonator can be coupled with the waveguide

Generation of vortices in azimuthally and radially polarized Bessel beams using one-dimensional photonic crystal

Abstract: A new method of formation and spatial separation of radially and azimuthally polarized Bessel beams containing phase dislocation (Bessel vortex) is proposed. This method is based on using one-dimensional photonic crystal. It has been shown that on the bases of these structures effective and compact generators for radially and azimuthally polarized Bessel beams can be elaborated.