The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Chunqing Gao - One of the best experts on this subject based on the ideXlab platform.
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influences of atmospheric turbulence effects on the orbital angular momentum spectra of vortex beams
Photonics Research, 2016Co-Authors: Chunqing GaoAbstract:We investigate the atmospheric turbulence effects on orbital angular momentum (OAM) spectra of different kinds of vortex beams, including Laguerre–Gaussian (LG) beams and Bessel beams, numerically. We generate the holograms of atmospheric turbulence with different structure constants of the refractive index. The OAM spectra of distorted single-mode or multiplexed LG beams and Bessel beams are analyzed. Compared with the OAM spectra of the two kinds of vortex beams, the spectrum of the Bessel beams is more dispersive. The results illustrate that Bessel beams suffer more from turbulent atmosphere than LG beams.
Kuan Fang Ren - One of the best experts on this subject based on the ideXlab platform.
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analysis of radiation pressure force exerted on a biological cell induced by high order bessel beams using debye series
Journal of Quantitative Spectroscopy & Radiative Transfer, 2013Co-Authors: Kuan Fang Ren, Xiange Han, Lixin Guo, Shuxi GongAbstract:Debye series expansion (DSE) is employed to the analysis of radiation pressure force (RPF) exerted on biological cells induced by high-order Bessel beams (BB). The beam shape coefficients (BSCs) for high-order Bessel beams are calculated using analytical expressions obtained by the integral localized approximation (ILA). Different types of cells, including a real Chinese Hamster Ovary (CHO) cell and a lymphocyte which are respectively modeled by a coated and five-layered sphere, are considered. The RPF induced by high-order Bessel beams is compared with that by Gaussian beams and zeroth-order Bessel beams, and the effect of different scattering processes on RPF is studied. Numerical calculations show that high-order Bessel beams with zero central intensity can also transversely trap particle in the beam center, and some scattering processes can provide longitudinal pulling force.
Qiwen Zhan - One of the best experts on this subject based on the ideXlab platform.
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evanescent bessel beam generation via surface plasmon resonance excitation by a radially polarized beam
Optics Letters, 2006Co-Authors: Qiwen ZhanAbstract:A simple setup for generating evanescent Bessel beams is proposed. When a radially polarized beam is strongly focused onto a dielectric-metal interface, the entire beam is p-polarized with respect to the dielectric-metal interface, enabling excitation of surface plasmons from all directions. The angular selectivity of surface plasmon excitation mimics the function of an axicon, leading to an evanescent nondiffracting Bessel beam. The created evanescent Bessel beam may be used as a virtual probe for near-field optical imaging and sensing applications.
Xiaojun Xu - One of the best experts on this subject based on the ideXlab platform.
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generating a bessel gaussian beam for the application in optical engineering
Scientific Reports, 2016Co-Authors: Jing Wang, Pin Lu, Xiaojun XuAbstract:Bessel beam is the important member of the family of non-diffracting beams and has many novel properties which can be used in many areas. However, the source of Bessel beam generated by the existing methods can be used only in a short distance due to its low power. In this paper, based on the coherent combining technology, we have proposed a method which can be used to generate a high-power Bessel beam. Even more, we give an innovative idea to form vortex phase by using discontinuous piston phase. To confirm the validity of this method, the intensity evolution of the combined beam and the Bessel-Gaussian beam at different propagation distance have been studied and compared. Meanwhile, the experimental realization has been discussed from the existing experimental result related to the coherent combining technology.
Francisco Camarena - One of the best experts on this subject based on the ideXlab platform.
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Generating Bessel beams with broad depth-of-field by using phase-only acoustic holograms
Scientific Reports, 2019Co-Authors: Sergio Jiménez-gambín, Noé Jiménez, José M. Benlloch, Francisco CamarenaAbstract:We report zero-th and high-order acoustic Bessel beams with broad depth-of-field generated using acoustic holograms. While the transverse field distribution of Bessel beams generated using traditional passive methods is correctly described by a Bessel function, these methods present a common drawback: the axial distribution of the field is not constant, as required for ideal Bessel beams. In this work, we experimentally, numerically and theoretically report acoustic truncated Bessel beams of flat-intensity along their axis in the ultrasound regime using phase-only holograms. In particular, the beams present a uniform field distribution showing an elongated focal length of about 40 wavelengths, while the transverse width of the beam remains smaller than 0.7 wavelengths. The proposed acoustic holograms were compared with 3D-printed fraxicons, a blazed version of axicons. The performance of both phase-only holograms and fraxicons is studied and we found that both lenses produce Bessel beams in a wide range of frequencies. In addition, high-order Bessel beam were generated. We report first order Bessel beams that show a clear phase dislocation along their axis and a vortex with single topological charge. The proposed method may have potential applications in ultrasonic imaging, biomedical ultrasound and particle manipulation applications using passive lenses.