Optical Vortices: 3D Optical Vortex Lattices (Ann. Phys. 7/2021)

Optical vortex arrays have been generated using simple, novel, and stable reversed-wavefront folding interferometer. Two new interferometric configurations were used for generating a variety of optical vortex lattices. In the first interferometric configuration one cube beam splitter (CBS) was used in one arm of Mach-Zehnder interferometer for splitting and combining the collimated beam, and one mirror of another arm is replaced by second CBS. At the output of interferometer, three-beam interference gives rise to optical vortex arrays. In second interferometric configuration, a divergent wavefront was made incident on a single CBS which splits and combines wavefronts leading to the generation of vortex arrays due to four-beam interference. It was found that the orientation and structure of the optical vortices can be stably controlled by means of changing the rotation angle of CBS.

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Influence of attenuation on the generation of optical vortices in multihelicoidal optical fibers

Journal of Physics Conference Series ◽

10.1088/1742-6596/2103/1/012149 ◽

2021 ◽

Vol 2103 (1) ◽

pp. 012149

Author(s):

C N Alexeyev ◽

S S Alieva ◽

E V Barshak ◽

B P Lapin ◽

M A Yavorsky

Keyword(s):

Optical Fibers ◽

Fundamental Mode ◽

Optical Vortex ◽

Conversion Process ◽

Exceptional Point ◽

Optical Vortices ◽

Attenuation Coefficients ◽

Enhanced Sensitivity ◽

Scalar Approximation ◽

The Difference

Abstract In this paper we have studied influence of attenuation on conversion processes of the fundamental mode (FM) in multihelicoidal optical fibers (MHF) in the vicinity of the point of accidental spectrum degeneracy within the framework of the scalar approximation. To this end, we have obtained expressions for modes of the MHF, which consist of the FM and an optical vortex (OV), and shown that conversion of the FM into the OV takes place. The difference in the attenuation coefficients for the partial fields of MHF’s modes leads to deterioration in the conversion process even with an ideal system’s tuning. At sufficiently large values of attenuation coefficients the conversion of the incoming FM into the vortex vanishes. Also we have shown the presence of exceptional point (EP) in the spectra of modes of the MHF and demonstrated enhanced sensitivity of the fiber in the vicinity of the EP to perturbations.

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Strongly Focused Circularly Polarized Optical Vortices Regulated by a Fractal Conical Lens

Applied Sciences ◽

10.3390/app10010028 ◽

2019 ◽

Vol 10 (1) ◽

pp. 28

Author(s):

Zhirong Liu ◽

Kelin Huang ◽

Anlian Yang ◽

Xun Wang ◽

Philip H. Jones

Keyword(s):

Angular Momentum ◽

Optical Tweezers ◽

Numerical Aperture ◽

Optical Element ◽

Optical Vortex ◽

Optical Vortices ◽

Circularly Polarized ◽

Strong Focusing ◽

New Type ◽

Vortex Beams

In this paper, a recently-proposed pure-phase optical element, the fractal conical lens (FCL), is introduced for the regulation of strongly-focused circularly-polarized optical vortices in a high numerical aperture (NA) optical system. Strong focusing characteristics of circularly polarized optical vortices through a high NA system in cases with and without a FCL are investigated comparatively. Moreover, the conversion between spin angular momentum (SAM) and orbital angular momentum (OAM) of the focused optical vortex in the focal vicinity is also analyzed. Results revealed that a FCL of different stage S could significantly regulate the distributions of tight focusing intensity and angular momentum of the circularly polarized optical vortex. The interesting results obtained here may be advantageous when using a FCL to shape vortex beams or utilizing circularly polarized vortex beams to exploit new-type optical tweezers.

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Close-packed optical vortex lattices with controllable structures

Optics Express ◽

10.1364/oe.26.022965 ◽

2018 ◽

Vol 26 (18) ◽

pp. 22965 ◽

Cited By ~ 8

Author(s):

Xinzhong Li ◽

Haixiang Ma ◽

Hao Zhang ◽

Yuping Tai ◽

Hehe Li ◽

...

Keyword(s):

Optical Vortex ◽

Vortex Lattices

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Laser Beam Positioning by Using a Broken-Down Optical Vortex Marker

Applied Sciences ◽

10.3390/app11167677 ◽

2021 ◽

Vol 11 (16) ◽

pp. 7677

Author(s):

Ewa Frączek ◽

Wojciech Frączek ◽

Agnieszka Popiołek-Masajada

Keyword(s):

Laser Beam ◽

Open Space ◽

Optical Vortex ◽

Center Of Gravity ◽

High Order ◽

Optical Vortices

We propose the use of high-order optical vortices as markers in the positioning of a laser beam. The broken optical vortices are arranged in constellations. The center of gravity of these constellations makes it possible to position the beam carrying information encoded in the optical vortices. This paper describes three positioning methods using both intensity and phase maps. The methods described were tested in experiments performed in a laboratory and an open space.

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Phyllotaxis-inspired nanosieves with multiplexed orbital angular momentum

eLight ◽

10.1186/s43593-021-00005-9 ◽

2021 ◽

Vol 1 (1) ◽

Author(s):

Zhongwei Jin ◽

David Janoschka ◽

Junhong Deng ◽

Lin Ge ◽

Pascal Dreher ◽

...

Keyword(s):

Free Space ◽

High Capacity ◽

Vortex Generator ◽

Optical Vortex ◽

Optical Vortices ◽

Time Resolved ◽

Optical Applications ◽

On Chip ◽

Pine Cones ◽

Meta Atom

AbstractNanophotonic platforms such as metasurfaces, achieving arbitrary phase profiles within ultrathin thickness, emerge as miniaturized, ultracompact and kaleidoscopic optical vortex generators. However, it is often required to segment or interleave independent sub-array metasurfaces to multiplex optical vortices in a single nano-device, which in turn affects the device’s compactness and channel capacity. Here, inspired by phyllotaxis patterns in pine cones and sunflowers, we theoretically prove and experimentally report that multiple optical vortices can be produced in a single compact phyllotaxis nanosieve, both in free space and on a chip, where one meta-atom may contribute to many vortices simultaneously. The time-resolved dynamics of on-chip interference wavefronts between multiple plasmonic vortices was revealed by ultrafast time-resolved photoemission electron microscopy. Our nature-inspired optical vortex generator would facilitate various vortex-related optical applications, including structured wavefront shaping, free-space and plasmonic vortices, and high-capacity information metaphotonics.

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Focal beam structuring by triple mixing of optical vortex lattices

Optical and Quantum Electronics ◽

10.1007/s11082-021-03399-5 ◽

2021 ◽

Vol 54 (1) ◽

Author(s):

Lyubomir Stoyanov ◽

Georgi Maleshkov ◽

Ivan Stefanov ◽

Gerhard G. Paulus ◽

Alexander Dreischuh

Keyword(s):

Spatial Light Modulator ◽

Optical Vortex ◽

Spatial Light Modulators ◽

Reliable Control ◽

Control Parameters ◽

Light Modulator ◽

Vortex Lattices ◽

On Demand ◽

Ordered Arrays ◽

Light Modulators

AbstractOn-demand generation and reshaping of arrays of focused laser beams is highly desired in many areas of science and technology. In this work, we present a versatile approach for laser beam structuring in the focal plane of a lens by triple mixing of square and/or hexagonal optical vortex lattices (OVLs). In the artificial far field the input Gaussian beam is reshaped into ordered arrays of bright beams with flat phase profiles. This is remarkable, since the bright focal peaks are surrounded by hundreds of OVs with their dark cores and two-dimensional phase dislocations. Numerical simulations and experimental evidences for this are shown, including a broad discussion of some of the possible scenarios for such mixing: triple mixing of square-shaped OVLs, triple mixing of hexagonal OVLs, as well as the two combined cases of mixing square-hexagonal-hexagonal and square-square-hexagonal OVLs. The particular ordering of the input phase distributions of the OV lattices on the used spatial light modulators is found to affect the orientation of the structures ruled by the hexagonal OVL. Reliable control parameters for the creation of the desired focal beam structures are the respective lattice node spacings. The presented approach is flexible, easily realizable by using a single spatial light modulator, and thus accessible in many laboratories.

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Generation of optical vortex lattices by a coherent beam combining system

Optics Letters ◽

10.1364/ol.425186 ◽

2021 ◽

Author(s):

Jinhu LONG ◽

Tianyue Hou ◽

Qi Chang ◽

Rongtao Su ◽

Yu Tao ◽

...

Keyword(s):

Optical Vortex ◽

Coherent Beam ◽

Coherent Beam Combining ◽

Vortex Lattices ◽

Beam Combining

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Quantifying the quality of optical vortices by evaluating their intensity distributions

10.21203/rs.3.rs-1156292/v1 ◽

2021 ◽

Author(s):

Mateusz Szatkowski ◽

Brandon Norton ◽

Jan Masajada ◽

Rosario Porras-Aguilar

Keyword(s):

Intensity Distribution ◽

Vortex Core ◽

Ring Width ◽

Optical Vortex ◽

Optical Vortices ◽

Cross Sectional ◽

Core Diameter ◽

Intensity Parameters

Abstract Optical vortices are widely used in optics and photonics, ranging from microscopy and communications to astronomy. However, little work has been done to quantify the quality of scalar optical vortices. Since the quality of an optical vortex affects measurements and conclusions derived from their use, development of tools to evaluate the vortex quality is crucial. Moreover, the quality of a vortex strongly depends on the application. Therefore, this work aims to establish metrics for the evaluation of optical vortex quality. We propose to evaluate vortex quality using the following intensity parameters: eccentricity of the intensity distribution, cross-sectional peak-to-valley measurements, cross-sectional peak difference, and the ratio of the ring width to the vortex core diameter (doughnut-ratio). These parameters can be used as a guide for the quality of optical vortices depending on their implementation for specific optical technologies.

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