scholarly journals Nonparaxial Propagation Properties of Specially Correlated Radially Polarized Beams in Free Space

2019 ◽  
Vol 9 (5) ◽  
pp. 997
Author(s):  
Lina Guo ◽  
Li Chen ◽  
Rong Lin ◽  
Minghui Zhang ◽  
Yiming Dong ◽  
...  
Keyword(s):  
Free Space ◽  
Degree Of Polarization ◽  
Average Intensity ◽  
Polarized Beams ◽  
Diffraction Integral ◽  
Spectral Density Matrix ◽  
Potential Applications ◽  
Spectral Degree ◽  
Propagation Properties ◽  
Radially Polarized

A specially correlated radially polarized (SCRP) beam with unusual physical properties on propagation in the paraxial regime was introduced and generated recently. In this paper, we extend the paraxial propagation of an SCRP beam to the nonparaxial regime. The closed-form 3 × 3 cross-spectral density matrix of a nonparaxial SCRP beam propagating in free space is derived with the aid of the generalized Rayleigh–Sommerfeld diffraction integral. The statistical properties, such as average intensity, degree of polarization, and spectral degree of coherence, are studied comparatively for the nonparaxial SCRP beam and the partially coherent radially polarized (PCRP) beam with a conventional Gaussian–Schell-model correlation function. It is found that the nonparaxial properties of an SCRP beam are strikingly different from those of a PCRP beam. These nonparaxial properties are closely related to the correlation functions and the beam waist width. Our results may find potential applications in beam shaping and optical trapping in nonparaxial systems.

Paraxial Propagation Properties of Radially Polarized Odd‐Pearcey Gaussian Beams in Free Space

2021 ◽  
pp. 2100055
Author(s):  
Mingyue Fang ◽  
Xiang Liao ◽  
Jiajia Zhao ◽  
Chuangjie Xu ◽  
Yixiao Zhang ◽  
...  
Keyword(s):  
Free Space ◽  
Gaussian Beams ◽  
Propagation Properties ◽  
Radially Polarized

scholarly journals Propagation of Rectangular Multi-Gaussian Schell-Model Array Beams through Free Space and Non-Kolmogorov Turbulence

2020 ◽  
Vol 10 (2) ◽  
pp. 450 ◽  
Author(s):  
Xiaolu Ma ◽  
Dajun Liu ◽  
Yaochuan Wang ◽  
Hongming Yin ◽  
Haiyang Zhong ◽  
...  
Keyword(s):  
Free Space ◽  
Coherence Length ◽  
Gaussian Beams ◽  
Average Intensity ◽  
Beam Size ◽  
Kolmogorov Turbulence ◽  
Propagation Properties ◽  
Analytical Expressions ◽  
Effective Beam

In this paper, rectangular multi-Gaussian Schell-model (MGSM) array beams, which consists N×D beams in rectangular symmetry, are first introduced. The analytical expressions of MGSM array beams propagating through free space and non-Kolmogorov turbulence are derived. The propagation properties, such as normalized average intensity and effective beam sizes of MGSM array beams are investigated and analyzed. It is found that the propagation properties of MGSM array beams depend on the parameters of the MGSM source and turbulence. It can also be seen that the beam size of Gaussian beams translated by MGSM array beams will become larger as the total number of terms, M, increases or coherence length, σ , decreases, and the beam in stronger non-Kolmogorov turbulence (larger α and l 0 , or smaller L 0 ) will also have a larger beam size.

scholarly journals Plasmonic nanocavity enhanced vibration of graphene by a radially polarized optical field

Nanophotonics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 2017-2023
Author(s):  
Xuwei Li ◽  
Tingting Zhang ◽  
Zhengkun Fu ◽  
Bowen Kang ◽  
Xiaohu Mi ◽  
...  
Keyword(s):  
2D Materials ◽  
Near Field ◽  
Interlayer Coupling ◽  
Optical Field ◽  
Vibrational Signal ◽  
Polarized Beams ◽  
Plane Vibration ◽  
Out Of Plane ◽  
Potential Applications ◽  
Radially Polarized

AbstractThe combination of 2D materials and surface plasmon can produce some novel optical phenomena that have attracted much attention. Illuminated by light with different polarization states, the field distribution around the plasmonic structure can control the light-matter interaction. The interaction between graphene and light can be strongly enhanced by employing radially polarized beams in a nanocavity. Here, we study the selectively enhanced vibration of graphene in a coupled plasmonic gold nanocavity with a radially polarized optical field, and the coupling and enhancing mechanisms are investigated both experimentally and numerically. By focusing a radially polarized beam, a high z component of a localized near field in the nanocavity is provided to strongly enhance the interaction between graphene and light, which can be used to enhance the vibrational signal of the interlayer. For the in-plane vibration of graphene, a similar enhancement is obtained with a linearly and radially polarized optical field. A plasmonic nanocavity is used to enhance the vibration of graphene, which provides potential applications in studying the out-of-plane vibration mode and exploring the mechanism of the interlayer coupling of 2D materials.

Polarization Changes of Elliptically Polarized Laser Beams Propagating in Slant Path through Turbulent Atmosphere

2012 ◽  
Vol 605-607 ◽  
pp. 1994-1998
Author(s):  
Ming Gao ◽  
Wei Na Nan ◽  
Hong Lv
Keyword(s):  
Density Matrix ◽  
Laser Beam ◽  
Turbulent Atmosphere ◽  
Laser Beams ◽  
Degree Of Polarization ◽  
Spectral Density Matrix ◽  
Cross Spectral Density ◽  
Spectral Degree ◽  
Slant Path ◽  
Elliptically Polarized

The spectral degree of polarization is studied based on the cross-spectral density matrix of an elliptically polarized laser beam propagating in the slant path through turbulent atmosphere. In addition, the effects of the turbulence on the spectral degree of polarization of an elliptically polarized Gaussian Schell-model beam and a partially polarized laser beam are contrasted and analyzed. And the different elliptically polarized laser beams are investigated.

scholarly journals Propagation Properties of Vortex Cosine-Hyperbolic-Gaussian Beams Through Oceanic Turbulence

2021 ◽  
Author(s):  
Mohamed Lazrek ◽  
Zoubir Hricha ◽  
Abdelmajid Belafhal
Keyword(s):  
Dissipation Rate ◽  
Sea Water ◽  
Turbulent Medium ◽  
Average Intensity ◽  
Underwater Communication ◽  
Salinity Fluctuation ◽  
Oceanic Turbulence ◽  
Diffraction Integral ◽  
Beam Parameters ◽  
Propagation Properties

Abstract Based on the extended Huygens–Fresnel diffraction integral, the analytical expression of the average intensity for a vortex cosine hyperbolic-Gaussian beam (vChGB) propagating in oceanic turbulence is derived in detail. From the derived formula, the propagation properties of a vChGB in oceanic turbulence, including the average intensity distribution and the beam spreading are discussed with numerical examples. It is shown that oceanic turbulence influences strongly the propagation properties of the beam in the turbulent medium. The vChGB may propagate within shorter distance in weak oceanic turbulence by increasing the dissipation rate of mean-square temperature and the ratio of temperature to salinity fluctuation or by increasing the dissipation rate of turbulent kinetic energy per unit mass of sea water. Meanwhile, the evolution properties of the vChGB in the oceanic turbulence are affected by the initial beam parameters, namely the decentered parameter b, the topological charge M, the beam waist width ω0 and the wavelength λ. The obtained results can be beneficial for applications in optical underwater communication and remote sensing domain, imaging, and so on.

scholarly journals Effects of Turbulent Atmosphere on the Propagation Properties of Vortex Hermite-cosine-hyperbolic-Gaussian Beams

2021 ◽  
Author(s):  
Zoubir Hricha ◽  
Mohammed Lazrek ◽  
Mohammed Yaalou ◽  
Abdelmajid Belafhal
Keyword(s):  
Turbulent Atmosphere ◽  
Analytical Formula ◽  
Propagation Distance ◽  
Central Peak ◽  
Average Intensity ◽  
Practical Applications ◽  
Diffraction Integral ◽  
Peak Intensity ◽  
Beam Parameters ◽  
Propagation Properties

Abstract The propagation properties of a vortex Hermite-cosh-Gaussian beam (vHChGB) in atmospheric turbulence are investigated based on the extended Huygens–Fresnel diffraction integral and Rytov method. The analytical formula for the average intensity of a vHChGB propagating in turbulent atmosphere is derived in detail. The influence of the turbulence strength on the intensity distribution under the change of beam parameters conditions is illustrated numerically and discussed. Results show the profile of the initial vHChGB remains unchanged within small propagation distance range, and at certain propagation distance a central peak intensity appears, and finally the beam evolves into Gaussian profile–like in far-field. The rising speed of the central peak intensity is faster when the turbulence strength is larger or the beam parameters such as the beam order, the vortex charge and the Gaussian waist width are smaller. With a small decentered parameter b, the beam profile changes faster as the wavelength is larger, whereas the reverse behavior occurs when b is large. The obtained results may be useful for the practical applications of vHChGB in optical communications and remote sensing.

Propagation properties of radially polarized Pearcey-Gauss vortex beams in free space

2020 ◽  
Vol 29 (6) ◽  
pp. 064202
Author(s):  
Xinpeng Chen ◽  
Chuangjie Xu ◽  
Qian Yang ◽  
Zhiming Luo ◽  
Xixian Li ◽  
...  
Keyword(s):  
Free Space ◽  
Vortex Beams ◽  
Propagation Properties ◽  
Radially Polarized

scholarly journals Characteristics of Partially Coherent Circular Flattened Gaussian Vortex Beams in Turbulent Biological Tissues

2019 ◽  
Vol 9 (5) ◽  
pp. 969 ◽  
Author(s):  
Yongzhou Ni ◽  
Yimin Zhou ◽  
Guoquan Zhou ◽  
Ruipin Chen
Keyword(s):  
Spectral Density ◽  
Analytical Formula ◽  
Biological Tissues ◽  
Degree Of Polarization ◽  
Average Intensity ◽  
Partially Coherent ◽  
Spectral Density Matrix ◽  
Cross Spectral Density ◽  
Vortex Beams ◽  
The Cross

The characteristics of partially coherent circular flattened Gaussian vortex beams in turbulent biological tissues are investigated, and the analytical formula for the cross-spectral density of this beam is derived. According to the cross-spectral density matrix, the average intensity and degree of polarization can be obtained. By numerical simulation, the distributions of the normalized average intensity and degree of polarization of partially coherent circular flattened Gaussian vortex beams are demonstrated on the research plane of turbulent biological tissues. The effects of the two beam parameters, the topological charge, the two transverse coherent lengths, and the structural constant of biological turbulence on the normalized average intensity and degree of polarization are analyzed. This study is of great significance for the potential application of partially coherent circular flattened Gaussian vortex beams in medical imaging and medical diagnosis.

scholarly journals Propagation of Vortex Cosine-hyperbolic-gaussian Beams in Atmospheric Turbulence

2021 ◽  
Author(s):  
Zoubir Hricha ◽  
Mohammed Lazrek ◽  
Mohammed Yaalou ◽  
Abdelmajid Belafhal
Keyword(s):  
Atmospheric Turbulence ◽  
Propagation Distance ◽  
Central Peak ◽  
Average Intensity ◽  
Gaussian Width ◽  
Diffraction Integral ◽  
Constant Strength ◽  
Beam Parameters ◽  
Propagation Properties ◽  
Rytov Method

Abstract In this paper, the propagation properties of a vortex cosh-Gaussian beam (vChGB) in turbulent atmosphere are investigated. Based on the extended Huygens–Fresnel diffraction integral and the Rytov method, the analytical expression for the average intensity of the vChGB propagating in the atmospheric turbulence is derived. The effects of the turbulent strength and the beam parameters on the intensity distribution and the beam spreading are illustrated numerically and analyzed in detail. It is shown that upon propagating, the incident vChGB keeps its initial hollow dark profile within a certain propagation distance, then the field loses gradually its central hole-intensity and transformed into a Gaussian–like beam for large propagation distance. The rising speed of the central peak is demonstrated to be faster when the constant strength turbulence or the wavelength are larger and the Gaussian width is smaller. The obtained results can be beneficial for applications in optical communications and remote sensing.

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