scispace - formally typeset
Search or ask a question
Topic

Bessel beam

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


Papers
More filters
Proceedings ArticleDOI
TL;DR: In this paper, a nonlinear approach based on the Grueneisen relaxation effect was proposed to suppress the side-lobe artifacts in photoacoustic imaging, which extends the focal depth of OR-PAM and speeds up volumetric imaging.
Abstract: The short focal depth of a Gaussian beam limits the volumetric imaging speed of optical resolution photoacoustic microscopy (OR-PAM). A Bessel beam, which is diffraction-free, provides a long focal depth, but its side-lobes may deteriorate image quality when the Bessel beam is directly employed to excite photoacoustic signals in ORPAM. Here, we present a nonlinear approach based on the Grueneisen relaxation effect to suppress the side-lobe artifacts in photoacoustic imaging. This method extends the focal depth of OR-PAM and speeds up volumetric imaging. We experimentally demonstrated a 1-mm focal depth with a 7-μm lateral resolution and volumetrically imaged a carbon fiber and red blood cell samples.

1 citations

Journal ArticleDOI
TL;DR: In this paper, a ring-shaped Gauss-Bessel beam is generated by imprinting a vortex with high topological charge in a Gaussian beam and the phase singularities are subsequently removed and the ringshaped beam focused/fourier-transformed by a thin lens.

1 citations

Journal ArticleDOI
TL;DR: This work deals with the wave equation in paraxial approximation together with the diffraction Fresnel integral and applies the analytical method proposed by Zamboni-Rached et al.
Abstract: In this work, we describe analytically the diffraction of some important beams due to a circular obstacle. In order to obtain the desired results, we deal with the wave equation in paraxial approximation together with the diffraction Fresnel integral and apply the analytical method proposed by Zamboni-Rached et al. [Appl. Opt.51, 3370–3379 (2012)APOPAI0003-693510.1364/AO.51.003370]. As a byproduct of our method, we notice the formation of the Poisson–Arago spot for ordinary beams (plane wave and Gaussian beam) and a reconstruction of the beam for nondiffracting beams (Bessel beam). Then, we pass to a vectorial analysis for better describing the electromagnetic beams.

1 citations

Proceedings ArticleDOI
02 Mar 2020
TL;DR: In this paper, an all-laser based fabrication process for optical elements made of glass is reported, focusing on the influence of the pulse distance as well as the laser fluence on the ablation depth, ablation efficiency and surface roughness.
Abstract: We report on an all-laser based fabrication process for optical elements made of glass. Two laser systems, namely a 1030 nm ultrashort pulsed and a CO2 laser are applied. Firstly, a femtosecond laser is used to precisely ablate the glass substrate layer-wise, forming the designed geometry. This ablation process is investigated in detail, focusing on the influence of the pulse distance as well as the laser fluence on the ablation depth, ablation efficiency and the surface roughness. It is found that the ablation depth decrease with increasing pulse distance while the ablation efficiency shows a maximum in the middle of the pulse distance regime for all investigated fluences. Contrary to these results, no significant influence on the surface roughness is observed. The well developed ultrashort pulsed laser ablation process is demonstrated for the fabrication of optical preforms such as cone-shaped (axicon), spherical and cylindrical lenses. In order to meet high surface quality requirements, inevitable stipulated for optical use, the surface roughness of the generated elements has to be reduced by CO2 laser polishing. To demonstrate the subsequent surface finishing process, a complex optic geometry i.e. an axicon array consisting of 37 individual axicons is fabricated within 23 minutes while the polishing shows a reduction of the surface roughness from 0.36 μm to 48 nm. For a detailed investigation of the fabricated optic, the axicon array is mounted into the ultrashort pulsed laser machine. Several sub-Bessel beams exhibiting the typical zeroth-order Bessel beam intensity distribution are observed, in turn confirming the applied manufacturing process to be well applicable for the fabrication of complex optic geometries. Cross-sections of the quasi-Bessel beam at the axicon in the middle of the array in both, x- and y-direction, show an almost identical intensity profile, indicating the high contour accuracy of the axicon. The diameter of the sub-beam is measured to be 9.5 μm (FWHM) and the Bessel range in propagation direction amounts to 8.0 mm (FWHM).

1 citations

Proceedings ArticleDOI
TL;DR: In this paper, a very simple fringes projection set-up based on holistic printing method using a axicon to generate the self-interferogramm of a Bessel beam was presented.
Abstract: Fabrication of circular gratings formed of radially periodic circular lines is presented. It is a very simple fringes projection set-up based on holistic printing method using a axicon to generate the self-interferogramm of a Bessel beam using a transmissive cone. The new holographic optical interference scheme has been designed to produce circular lines based interferogram from a azimuthally polarized beam. The angle of the cone is adapted to cover a restricted periods range. The principle of the method is described and applied to the fabrication of a radial polarizer of sub-micron period.

1 citations


Network Information
Related Topics (5)
Resonator
76.5K papers, 1M citations
87% related
Laser
353.1K papers, 4.3M citations
84% related
Optical fiber
167K papers, 1.8M citations
84% related
Polarization (waves)
65.3K papers, 984.7K citations
79% related
Diffraction
63.7K papers, 1M citations
79% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202373
2022149
2021113
2020126
2019134
2018140