Review
Engineering, Multidisciplinary
D. G. Pires, N. M. Litchinitser
Summary: This paper investigates the nonlinear light-matter interactions of complex light beams with rotational degrees of freedom in engineered nonlinear colloidal media. By utilizing both variational and perturbative approaches, the dynamics and stability of non-cylindrical optical vortices, elliptical optical vortices, and higher-order Bessel beams integrated in time are predicted.
Article
Engineering, Electrical & Electronic
Wenpu Geng, Yuxi Fang, Yingning Wang, Changjing Bao, Hao Zhang, Yongxiong Ren, Zhongqi Pan, Yang Yue
Summary: This paper summarizes the characteristics of optical fibers with concentric ring cores for highly dispersive OAM modes and briefly introduces the applications of double-ring core fibers, photonic crystal fibers, and triple-ring core fibers.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
R. Matthias Geilhufe, Wolfram Hergert
Summary: High-intensity THz lasers can coherently excite individual phonon modes, enabling ultrafast control of emergent magnetism in functional materials. Recent experiments suggest significant magnetization in various materials, challenging the theoretical prediction of tiny phonon magnetic moments. We explain this phenomenon by deriving a coupling mechanism between phonon angular momentum and electron spin, causing transient level splitting and resulting magnetization.
Article
Optics
Mikko Partanen, Jukka Tulkki
Summary: The relativistic theory of time- and position-dependent energy and momentum densities of light in low-loss dispersive media has been a largely unsolved challenge until now. This work presents the stress-energy-momentum tensors of the field and dispersive medium using the mass-polariton theory of light, demonstrating symmetry and invariant properties for all inertial observers. The consistent theory provides further insight into the classical limit of the quantum mechanical spin of light in a medium and predicts experimentally accessible phenomena such as the atomic mass density wave associated with light.
Article
Nanoscience & Nanotechnology
Jian Chen, Chenhao Wan, Andy Chong, Qiwen Zhan
Summary: This study experimentally generated cylindrically polarized wavepackets with transverse orbital angular momentum, demonstrating the coexistence of spatiotemporal optical vortex with spatial polarization singularity. The results extend the scope of spatiotemporal wavepacket research and pave the way for applications in various fields such as light-matter interaction, optical tweezers, spatiotemporal spin-orbit angular momentum coupling, etc.
Article
Optics
Xiaojin Yin, Ziyue Zhao, Pengqi Hao, Jinhong Li
Summary: The spin-orbit interactions of circularly polarized beams and circularly polarized vortex beams in radial gradient-index (GRIN) fibers are analyzed using the generalized Huygens-Fresnel principle and the GRIN fiber's ABCD matrix. The spin angular momentum (SAM) is only related to the polarization helicity, while the orbital angular momentum (OAM) is only related to the topological charge m. These two quantities do not crosstalk or convert between each other. No spin-orbit interactions occur at the focal plane of the GRIN fiber. The same characteristics are observed for partially coherent circularly polarized beams and partially coherent circularly polarized vortex beams in the GRIN fiber.
Article
Engineering, Electrical & Electronic
Wenpu Geng, Yuxi Fang, Yingning Wang, Changjing Bao, Zhi Wang, Yan-ge Liu, Hao Huang, Yongxiong Ren, Zhongqi Pan, Yang Yue
Summary: In this research, a germanium-doped highly dispersive coupled ring-core fiber (HD-CRF) is proposed and designed, which can achieve flexible control over its dispersion properties by optimizing fiber geometrical parameters. The OAM(1,1) mode in the designed CRF exhibits extremely negative chromatic dispersion, making it promising for various CD-related applications of complex vortex modes in optical fiber. Furthermore, by adjusting the mole fraction of GeO2 and fiber structure parameters, the most dispersive wavelength of the OAM(1,1) mode can be flexibly controlled over a wide spectral range with minimal CD variation.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Manman Li, Shaohui Yan, Yanan Zhang, Yuan Zhou, Baoli Yao
Summary: This article provides an overview of recent advances in optical manipulation with orbital angular momentum (OAM), including basic theories, computational approaches, and applications. By utilizing the distinct characteristics of OAM beams, such as helical wave fronts and doughnut intensity profiles, innovative particle manipulation and optical spin-orbit interaction can be achieved.
Article
Optics
Li Ma, Zijun Zhan, Chao Chen, Chunxiang Liu, Chuanfu Cheng
Summary: Control of orbital angular momentum is crucial for ultrashort pulses. We propose an approach for mode selection using an optical mask with a spiral array, which allows flexible generation of structured orbital angular momentum modes.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Guo Liang, Bingli Yuan, Yuan Li, Xiangwei Kong, Wenjing Cheng, Hongzhen Qiao, Xubo Hu
Summary: The evolutionary properties of optical vortices overlaid with Gaussian backgrounds in optical tweezers were analyzed. A Tornado-like pattern, with superior trapping ability for microparticles, is obtained when the Gaussian background is wide enough compared to the optical vortices. The Tornado-like pattern shows similar structures in intensity and phase, with the latter being a clockwise rotation of the former.
RESULTS IN PHYSICS
(2021)
Article
Optics
Jinfu Zeng, Shubo Cheng, Shuo Liu, Geng Zhang, Shaohua Tao, Wenxing Yang
Summary: This study investigates the dynamic evolution and self-healing properties of bored helico-conical beams with different filter parameter S. The self-healing effect of the beams is perfect when D approaches 0. The effective self-healing distance decreases exponentially with increasing filter parameter S, and the corresponding transverse energy flows are analyzed. The experimental results agree well with the simulation results.
Article
Optics
Victor V. Kotlyar, Alexey A. Kovalev, Pouria Amiri, Peyman Soltani, Saifollah Rasouli
Summary: The study investigates the topological charge of the sum of two axisymmetric off-axis Laguerre-Gaussian beams, finding that when the indices are the same, the combined beam has the topological charge of one of the individual beams. Different indices result in the sum taking on specific values for the topological charge. Additionally, rules for selecting a feasible topological charge value are established, along with exploring the effects of exchanging and shifting between beams on the topological charge.
Review
Optics
Jian Chen, Chenhao Wan, Qiwen Zhan
Summary: The combination of photonic OAM and SAM provides additional information for new sensing mechanisms and light-matter interactions. Diverse photonic SAM and OAM states can be generated through careful engineering of optical fields. Specifically engineered photonic AM states have potential applications in optical tweezers, directional coupling, and optical information transmission and processing.
ADVANCED PHOTONICS
(2021)
Article
Multidisciplinary Sciences
Hongliang Zhang, Yeyang Sun, Junyi Huang, Bingjun Wu, Zhaoju Yang, Konstantin Y. Bliokh, Zhichao Ruan
Summary: This article reports the topologically robust generation of acoustic spatiotemporal vortex pulses using mirror-symmetry breaking meta-gratings, paving the way for exploring spatiotemporal structured waves in acoustics and beyond.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Yichen Ma, Haoqi Zhao, Na Liu, Zihe Gao, Seyed Sepehr Mohajerani, Licheng Xiao, James Hone, Liang Feng, Stefan Strauf
Summary: Researchers demonstrate a method to control the spin angular momentum and orbital angular momentum of light by coupling a quantum emitter with a ring resonator. They achieve spin-orbit locking and chiral single-photon emission and create optical vortices carrying orbital angular momentum states.
Article
Astronomy & Astrophysics
Mike Lockwood, Sarah N. Bentley, Mathew J. Owens, Luke A. Barnard, Chris J. Scott, Clare E. Watt, Oliver Allanson
SPACE WEATHER-THE INTERNATIONAL JOURNAL OF RESEARCH AND APPLICATIONS
(2019)
Editorial Material
Astronomy & Astrophysics
Oliver Allanson, Liz Tindale, Tom Bradley
ASTRONOMY & GEOPHYSICS
(2019)
Article
Physics, Fluids & Plasmas
T. Neukirch, F. Wilson, O. Allanson
JOURNAL OF PLASMA PHYSICS
(2020)
Article
Astronomy & Astrophysics
O. Allanson, C. E. J. Watt, H. Ratcliffe, H. J. Allison, N. P. Meredith, S. N. Bentley, J. P. J. Ross, S. A. Glauert
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2020)
Article
Astronomy & Astrophysics
O. Allanson, C. E. J. Watt, H. J. Allison, H. Ratcliffe
Summary: Radiation belt codes are evolving to incorporate electron dynamics influenced by resonant wave-particle interactions, especially when dealing with wave power spectra that change rapidly on a timescale shorter than the computational time-step. Specific attention is given to the rapid growth of thermal instabilities and the challenges in accurately describing electron dynamics during this phase. The study utilizes a kinetic code to model electron interactions with whistler-mode waves in a thermally anisotropic background, revealing differences in behavior based on the level of anisotropy and the impact on diffusion and advection processes.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Mathew Owens, Oliver Allanson, Megan Maunder
ASTRONOMY & GEOPHYSICS
(2021)
Article
Astronomy & Astrophysics
R. T. Desai, J. P. Eastwood, R. B. Horne, H. J. Allison, O. Allanson, C. E. J. Watt, J. W. B. Eggington, S. A. Glauert, N. P. Meredith, M. O. Archer, F. A. Staples, L. Mejnertsen, J. K. Tong, J. P. Chittenden
Summary: This study demonstrates the ability to propagate high-energy particles through global magnetohydrodynamic simulations with precision, mapping the cross-field radial transport of relativistic electrons undergoing drift orbit bifurcations. The simulations predict that these bifurcations primarily occur within an Earth radius of the magnetopause loss cone, with noticeable differences between southward and northward interplanetary magnetic field orientations. Additionally, the study highlights the significant effect of the convective electric field on long-term transport and suggests that losses to the magnetopause and atmosphere may be a way to incorporate these drift orbit bifurcations in Fokker-Planck transport models.
JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
(2021)
Article
Astronomy & Astrophysics
Elias Roussos, Oliver Allanson, Nicolas Andre, Bruna Bertucci, Graziella Branduardi-Raymont, George Clark, Konstantinos Dialynas, Iannis Dandouras, Ravindra T. Desai, Yoshifumi Futaana, Matina Gkioulidou, Geraint H. Jones, Peter Kollmann, Anna Kotova, Elena A. Kronberg, Norbert Krupp, Go Murakami, Quentin Nenon, Tom Nordheim, Benjamin Palmaerts, Christina Plainaki, Jonathan Rae, Daniel Santos-Costa, Theodore Sarris, Yuri Shprits, Ali Sulaiman, Emma Woodfield, Xin Wu, Zonghua Yao
Summary: Jupiter's radiation belts are one of the most complex and energetic in the Solar System, posing unique challenges for exploration. Study of these belts provides opportunities for interdisciplinary research into high energy plasma physics processes and astrobiological implications. A dedicated multi-spacecraft mission to Jupiter is essential for advancing our understanding of radiation belt systems and exploring Jupiter's extended magnetosphere, moons, and rings.
EXPERIMENTAL ASTRONOMY
(2022)
Article
Astronomy & Astrophysics
Oliver Allanson, Thomas Elsden, Clare Watt, Thomas Neukirch
Summary: We derive weak turbulence and quasilinear models for relativistic charged particle dynamics in pitch-angle and energy space, due to interactions with electromagnetic waves. The Markovian approach used in this study has several advantages, including the self-consistent relationship between weak turbulence theory and resonant diffusion quasilinear theory, as well as the general nature of the Fokker-Planck equation and its dependence on specific timescales.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Astronomy & Astrophysics
Clare E. J. Watt, Hayley J. Allison, Sarah N. Bentley, Rhys L. Thompson, I. Jonathan Rae, Oliver Allanson, Nigel P. Meredith, Johnathan P. J. Ross, Sarah A. Glauert, Richard B. Horne, Shuai Zhang, Kyle R. Murphy, Dovile Rasinskaite, Shannon Killey
Summary: This study investigates the temporal variation of the Fokker-Planck equation in response to the diffusion coefficient changes due to pitch-angle diffusion caused by plasmaspheric hiss. By conducting ensemble numerical experiments informed by in-situ observations, the authors show that the distribution of diffusion coefficients plays a significant role in determining the ensemble solutions. The results also suggest the presence of rare but large diffusion coefficient values in certain locations, highlighting the importance of accurate cold plasma density models in radiation belt studies.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Astronomy & Astrophysics
Maria-Theresia Walach, Omakshi Agiwal, Oliver Allanson, Mathew J. Owens, I. Jonathan Rae, Jasmine K. Sandhu, Andy Smith
Summary: This perspective article explores a pragmatic approach to addressing chronic underrepresentation in space science awards nominations, highlighting the fallacy of pretending that simple hard work will guarantee success for everyone and emphasizing the influential role of awards in shaping community image and facilitating career advancement.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Physics, Fluids & Plasmas
Viktor A. Frantsuzov, Anton V. Artemyev, Xiao-Jia Zhang, Oliver Allanson, Pavel I. Shustov, Anatoli A. Petrukovich
Summary: This study investigates the mechanism of electron resonant interactions with incoherent but intense waves. The diffusion rates of electrons in this regime are found to be linearly proportional to the wave amplitude, contrary to the quadratic scaling in the quasi-linear diffusion model. Using observed wave amplitude distributions, it is shown that the quasi-linear diffusion model significantly overestimates electron scattering by incoherent, but intense whistler-mode waves. The implications of these findings for long-term electron flux dynamics simulations in space plasma systems are also discussed.
JOURNAL OF PLASMA PHYSICS
(2023)
Article
Physics, Fluids & Plasmas
Daniel J. Ratliff, Oliver Allanson
Summary: This study discusses the modulation stability and wave-particle interactions of parallel-propagating/field-aligned whistler-mode chorus waves in a warm plasma. Results show that accounting for the motion of ions and higher-order effects is necessary to capture the spatiotemporal evolution of the envelope and packet formation, providing insights into the origin of power band gaps.
JOURNAL OF PLASMA PHYSICS
(2023)
Article
Astronomy & Astrophysics
Adnane Osmane, Emilia Kilpua, Harriet George, Oliver Allanson, Milla Kalliokoski
Summary: This research report presents a drift-kinetic description of radial transport for the Earth's radiation belts, distinguishing between fast and diffusive radial transport and verifying it through in situ testing. The study shows that the acceleration by Alfvenic waves cannot be fully explained by diffusive models.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
T. Neukirch, I. Y. Vasko, A. V. Artemyev, O. Allanson
ASTROPHYSICAL JOURNAL
(2020)
