1
|
Petrov NI. Sharp focusing of partially coherent Bessel-correlated beams by a graded-index lens. OPTICS LETTERS 2023; 48:6048-6051. [PMID: 37966786 DOI: 10.1364/ol.506779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 10/29/2023] [Indexed: 11/16/2023]
Abstract
The nonparaxial focusing of partially coherent Bessel-correlated beams carrying vortices by a graded-index lens is investigated using the decomposition of the incident field into coherent modes and the quantum mechanical operator method. The influence of the coherence state and the incident beam aperture on tight focusing is analyzed. Our results show that a partially coherent Bessel-correlated beam can be focused into a spot of smaller size than coherent light.
Collapse
|
2
|
Petrov NI. Nonparaxial Propagation of Bessel Correlated Vortex Beams in Free Space. MICROMACHINES 2022; 14:38. [PMID: 36677099 PMCID: PMC9865740 DOI: 10.3390/mi14010038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 12/18/2022] [Accepted: 12/20/2022] [Indexed: 06/17/2023]
Abstract
The nonparaxial propagation of partially coherent beams carrying vortices in free space is investigated using the method of decomposition of the incident field into coherent diffraction-free modes. Modified Bessel correlated vortex beams with the wavefront curvature are introduced. Analytical expressions are presented to describe the intensity distribution and the degree of coherence at different distances. The evolution of the intensity distribution during beam propagation for various source parameters is analyzed. The effects of nonparaxiality in the propagation of tightly focused coherent vortex beams are analyzed.
Collapse
Affiliation(s)
- Nikolai I Petrov
- Scientific and Technological Centre of Unique Instrumentation of the Russian Academy of Sciences, 117342 Moscow, Russia
| |
Collapse
|
3
|
Niu K, Zhai Y, Wang F. Self-healing property of the self-rotating beam. OPTICS EXPRESS 2022; 30:30293-30302. [PMID: 36242136 DOI: 10.1364/oe.467586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Accepted: 07/17/2022] [Indexed: 06/16/2023]
Abstract
In this study, we demonstrate the self-healing of self-rotating beams with asymmetric intensity profiles. The proposed self-rotating beam exhibits an asymmetric intensity profile and self-healing properties in free-space propagation. In addition, the rotation direction and beam intensity profile of the self-rotating beam can be adjusted using the parameters a and b in the phase function. The effects of the position and size of the obstruction on the self-healing property of a self-rotating beam were studied both experimentally and numerically. The simulation and experimental results demonstrate that a self-rotating beam can overcome a block of obstacles and regenerate itself after a characteristic distance. Transverse energy flows were used to explain the self-healing properties. Moreover, the beam rotates during propagation, which can be used to capture and manipulate microscopic particles in a three-dimensional space. It is expected that these rotating beams with self-healing properties will be useful in penetrating obstacles for optical trapping, transportation, and optical therapy.
Collapse
|
4
|
Abstract
Nonparaxial propagation of the vector vortex light beams in free space was investigated theoretically. Propagation-induced polarization changes in vector light beams with different spatial intensity distributions were analyzed. It is shown that the hybrid vector Bessel modes with polarization-OAM (orbital angular momentum) entanglement are the exact solutions of the vector Helmholtz equation. Decomposition of arbitrary vector beams in the initial plane z = 0 into these polarization-invariant beams with phase and polarization singularities was used to analyze the evolution of the polarization of light within the framework of the 2 × 2 coherency matrix formalism. It is shown that the 2D degree of polarization decreases with distance if the incident vector beam is not the modal solution. The close relationship of the degree of polarization with the quantum-mechanical purity parameter is emphasized.
Collapse
|
5
|
Piquero G, Martínez-Herrero R, de Sande JCG, Santarsiero M. Synthesis and characterization of non-uniformly totally polarized light beams: tutorial. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2020; 37:591-605. [PMID: 32400535 DOI: 10.1364/josaa.379439] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/10/2020] [Indexed: 06/11/2023]
Abstract
Polarization of a light beam is traditionally studied under the hypothesis that the state of polarization is uniform across the transverse section of the beam. In such a case, if the paraxial approximation is also assumed, the propagation of the beam reduces to a scalar problem. Over the last few decades, light beams with spatially variant states of polarization have attracted great attention, due mainly to their potential use in applications such as optical trapping, laser machining, nanoscale imaging, polarimetry, etc. In this tutorial, an introductory treatment of non-uniformly totally polarized beams is given. Besides a brief review of some useful parameters for characterizing the polarization distribution of such beams across transverse planes, from both local and global points of view, several methods for generating them are described. It is expected that this tutorial will serve newcomers as a starting point for further studies on the subject.
Collapse
|
6
|
Razueva E, Abramochkin E. Multiple-twisted spiral beams. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2019; 36:1089-1097. [PMID: 31158141 DOI: 10.1364/josaa.36.001089] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 04/29/2019] [Indexed: 06/09/2023]
Abstract
We propose a method to construct paraxial light fields whose transverse intensity rotates as a whole during the field propagation (spiral beams), and the total rotation angle is an integer multiple of π/2 (multiple-twisted beams). We derive analytical expressions for the field complex amplitude by utilizing an integral description of Laguerre-Gaussian beams. This method provides a straightforward way to obtain multiple-twisted spiral beams of various intensity shapes and rotation rates.
Collapse
|
7
|
Piquero G, Santarsiero M, Martínez-Herrero R, de Sande JCG, Alonzo M, Gori F. Partially coherent sources with radial coherence. OPTICS LETTERS 2018; 43:2376-2379. [PMID: 29762596 DOI: 10.1364/ol.43.002376] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 04/08/2018] [Indexed: 05/28/2023]
Abstract
Partially coherent sources with radial coherence are proposed. They present a circularly symmetric intensity profile and a degree of coherence whose absolute value only depends on the angular difference between the two considered points. In particular, the source is completely coherent at pairs of points belonging to the same radius. The modal structure of such sources is determined in the general case, and conditions are derived under which the field propagated in paraxial approximation remains radially coherent at any transverse plane. In such cases, the angular dependence of the correlation function is preserved upon propagation, although the intensity profile generally changes. An example of this kind of source has been experimentally synthesized by means of a simple setup, and its coherence characteristics have been tested by means of a Young interferometer.
Collapse
|
8
|
Ostrovsky AS, García-García J, Rickenstorff-Parrao C, Olvera-Santamaría MA. Partially coherent diffraction-free vortex beams with a Bessel-mode structure. OPTICS LETTERS 2017; 42:5182-5185. [PMID: 29240168 DOI: 10.1364/ol.42.005182] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 11/13/2017] [Indexed: 06/07/2023]
Abstract
A new family of partially coherent beams carrying optical vortices is introduced. Any member of this family represents an incoherent superposition of fully coherent orthogonal Bessel modes with the same helical wavefront and is notable for its diffraction-free propagation. It is shown analytically and experimentally that such beams can be approximately generated in the Fourier-transforming optical system with a computer-controlled liquid-crystal spatial light modulator.
Collapse
|
9
|
Abramochkin E, Alieva T. Closed-form expression for mutual intensity evolution of Hermite-Laguerre-Gaussian Schell-model beams. OPTICS LETTERS 2017; 42:4032-4035. [PMID: 28957190 DOI: 10.1364/ol.42.004032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
We derive a comprehensive closed-form expression for the evolution of the mutual intensity (MI) of Hermite-Laguerre-Gaussian Schell-model beams (HLG-SMBs) during propagation through rotationally symmetric optical systems. We demonstrate that the MI of the beam associated with a given HLG mode at any transverse plane can be presented as a linear superposition of the MIs of the SMBs associated with the equal and lower index modes of the same type, but of complex argument. The obtained expression allows easy analysis of the evolution of the intensity distribution and the CCF of such beams and, in particular, an understanding of the coherence singularity formation and modification during the beam propagation.
Collapse
|
10
|
Giordano A, Verba R, Zivieri R, Laudani A, Puliafito V, Gubbiotti G, Tomasello R, Siracusano G, Azzerboni B, Carpentieri M, Slavin A, Finocchio G. Spin-Hall nano-oscillator with oblique magnetization and Dzyaloshinskii-Moriya interaction as generator of skyrmions and nonreciprocal spin-waves. Sci Rep 2016; 6:36020. [PMID: 27786261 PMCID: PMC5081538 DOI: 10.1038/srep36020] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/06/2016] [Indexed: 11/18/2022] Open
Abstract
Spin-Hall oscillators (SHO) are promising sources of spin-wave signals for magnonics applications, and can serve as building blocks for magnonic logic in ultralow power computation devices. Thin magnetic layers used as “free” layers in SHO are in contact with heavy metals having large spin-orbital interaction, and, therefore, could be subject to the spin-Hall effect (SHE) and the interfacial Dzyaloshinskii-Moriya interaction (i-DMI), which may lead to the nonreciprocity of the excited spin waves and other unusual effects. Here, we analytically and micromagnetically study magnetization dynamics excited in an SHO with oblique magnetization when the SHE and i-DMI act simultaneously. Our key results are: (i) excitation of nonreciprocal spin-waves propagating perpendicularly to the in-plane projection of the static magnetization; (ii) skyrmions generation by pure spin-current; (iii) excitation of a new spin-wave mode with a spiral spatial profile originating from a gyrotropic rotation of a dynamical skyrmion. These results demonstrate that SHOs can be used as generators of magnetic skyrmions and different types of propagating spin-waves for magnetic data storage and signal processing applications.
Collapse
Affiliation(s)
- A Giordano
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina, Italy
| | - R Verba
- Institute of Magnetism, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - R Zivieri
- Department of Physics and Earth Sciences and CNISM Unit of Ferrara, University of Ferrara, Ferrara, Italy
| | - A Laudani
- Department of Engineering, University of Roma Tre, Roma, Italy
| | - V Puliafito
- Department of Engineering, University of Messina, Messina, Italy
| | - G Gubbiotti
- Istituto Officina dei Materiali del CNR (CNR-IOM), Sede Secondaria di Perugia, c/o Dipartimento di Fisica e Geologia, University of Perugia, Perugia, Italy
| | - R Tomasello
- Department of Engineering, Polo Scientifico Didattico di Terni, University of Perugia, Terni, Italy
| | - G Siracusano
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina, Italy
| | - B Azzerboni
- Department of Engineering, University of Messina, Messina, Italy
| | - M Carpentieri
- Department of Electrical and Information Engineering, Politecnico di Bari, I-70125 Bari, Italy
| | - A Slavin
- Department of Physics, Oakland University, Rochester, MI 48309, USA
| | - G Finocchio
- Department of Mathematical and Computer Sciences, Physical Sciences and Earth Sciences, University of Messina, Messina, Italy
| |
Collapse
|
11
|
Rodrigo JA, Alieva T. Evolution of coherence singularities of Schell-model beams. OPTICS LETTERS 2015; 40:3635-3638. [PMID: 26258376 DOI: 10.1364/ol.40.003635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We show that the propagation of the widely used Schell-model partially coherent light can be easily understood using the ambiguity function. This approach is especially beneficial for the analysis of the mutual intensity of Schell-model beams (SMBs), which are associated with stable coherent beams such as Laguerre-, Hermite-, and Ince-Gaussian. We study the evolution of the coherence singularities during the SMB propagation. It is demonstrated that the distance of singularity formation depends on the coherence degree of the input beam. Moreover, it is proved that the shape, position, and number of singularity curves in far field are defined by the associated coherent beam.
Collapse
|
12
|
Borghi R, Gori F, Guattari G, Santarsiero M. Shape-invariant difference between two Gaussian Schell-model beams. JOURNAL OF THE OPTICAL SOCIETY OF AMERICA. A, OPTICS, IMAGE SCIENCE, AND VISION 2015; 32:790-796. [PMID: 26366902 DOI: 10.1364/josaa.32.000790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The difference between two Gaussian Schell-model cross-spectral densities can give a new genuine correlation function if suitable conditions are met. Generally speaking, the structure of such cross-spectral density changes in a complicated way upon propagation. We consider here the notable exception of shape-invariant beams, and we investigate their intensity and coherence properties. The modal analysis of this class of cross-spectral densities is exploited to devise a synthesis scheme for this type of beam.
Collapse
|
13
|
Gori F, Santarsiero M. Twisted Gaussian Schell-model beams as series of partially coherent modified Bessel-Gauss beams. OPTICS LETTERS 2015; 40:1587-1590. [PMID: 25831391 DOI: 10.1364/ol.40.001587] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We show that twisted Gaussian Schell-model (TGSM) beams can be represented through an incoherent superposition of partially coherent beams carrying optical vortices and whose cross-spectral densities are expressed in terms of modified Bessel functions. Moreover, starting from this result, we show that the modal expansion of the cross-spectral density of a TGSM source can be directly obtained through simple mathematics.
Collapse
|
14
|
Rodrigo JA, Alieva T. Recovery of Schell-model partially coherent beams. OPTICS LETTERS 2014; 39:1030-3. [PMID: 24562270 DOI: 10.1364/ol.39.001030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Partially coherent light is often preferable to its completely coherent counterpart in applications such as imaging, sensing, and free-space optical communications. To fully exploit its advantages, techniques able to retrieve information carried by the beam are required. Here, we develop and experimentally demonstrate a phase-space optics technique for complete spatial analysis of widely used Schell-model beams. It allows for fast information recovery and can be applied for quantitative phase imaging of objects under partially coherent illumination.
Collapse
|