Article
Mathematics, Interdisciplinary Applications
Junbo Chen, Jianhua Zeng
Summary: Investigated the existence, properties, and stability of one-dimensional matter-wave gap solitons and soliton clusters in optical lattices with competitive cubic-quintic nonlinearity, identifying stable and unstable regions for dark gap solitons and clusters.
CHAOS SOLITONS & FRACTALS
(2021)
Article
Optics
F. Kh. Abdullaev, J. S. Yuldashev, M. Ogren
Summary: The management of solitons in media with competing quadratic and cubic nonlinearities has been investigated. Two schemes involving rapid modulations of a mismatch parameter and the Kerr nonlinearity parameter have been studied. The averaged wave equations in time have been derived for both cases. The regions of parameters where stabilization is possible have been found in the case of mismatch management. It has been shown that the effective chi(2) nonlinearity depends on the intensity imbalance between the fundamental and second harmonics in the case of Kerr nonlinearity management. The predictions obtained from the averaged equations have been confirmed through numerical simulations of the full PDEs.
Article
Mathematics, Applied
Xiaoxi Xu, Feiyan Zhao, Yangui Zhou, Bin Liu, Xunda Jiang, Boris A. Malomed, Yongyao Li
Summary: The formation and dynamics of full vortex gap solitons (FVGSs) are investigated in two-component Bose-Einstein condensates with spin-orbit coupling, Zeeman splitting, and competing cubic and quintic nonlinear terms. Stable FVGS states are found to exist, with the vorticity present in both components. The system's linear spectrum is filled with these solitons, which can have positive or negative effective mass depending on the specific nonlinear terms.
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION
(2023)
Article
Engineering, Mechanical
Xing Zhu, Zhen Cai, Jinglin Liu, Shangwen Liao, Yingji He
Summary: This work demonstrates that non-parity-time-symmetric complex potentials can support continuous soliton families in competing cubic-quintic nonlinearities. The quintic nonlinearity coefficient influences the soliton existence and stability areas significantly.
NONLINEAR DYNAMICS
(2022)
Article
Astronomy & Astrophysics
Michele Grasso, Eleonora Villa, Mikolaj Korzynski, Sabino Matarrese
Summary: A new formulation for light propagation in geometric optics using bilocal geodesic operators is proposed and implemented through the BIGONLIGHT Mathematica package. The focus is on analyzing cosmological observables in a wall universe model within the post-Newtonian approximation, with nonlinear corrections found to be below 1%, consistent with prior literature.
Article
Mathematics
R. Alsaedi, A. Dhifli, A. Ghanmi
Summary: In this paper, the existence of two non-trivial solutions for a class of p-biharmonic problems is obtained by using a variational approach combined with the Nehari manifold method and fibreing maps.
COMPLEX VARIABLES AND ELLIPTIC EQUATIONS
(2021)
Article
Chemistry, Physical
Oksana Patsahan, Marek Litniewski, Alina Ciach
Summary: The study investigates the interaction between particles in a binary mixture under spherically-symmetrical potentials, leading to microsegregation. Both theory and MD simulations demonstrate coexistence of different phases with varying densities and degrees of order, with the phase diagram showing significant differences from mean-field predictions. The ordered phases exhibit crystalline structures in the solid form, while lacking in the liquid crystals, with a prolate shape noted in monocrystals that deviates from a spherical shape with increasing periodic order.
Article
Materials Science, Multidisciplinary
Lei Yan, Jianguo Zhang, Mingkai Wang, Zhongquan Nie
Summary: In this work, we studied the boosted optical nonlinearities of graphene oxide (GO) films by laser direct writing. The films were prepared by vacuum filtration method and partly reduced using a commercial carbon dioxide laser machine. The morphology, structure, and luminescence traits of the films were characterized, and their third-order optical nonlinearities were measured. The results show that the reduced GO films exhibit stronger optical nonlinearities, and the degree of enhancement depends on the spot size of laser processing.
Article
Engineering, Electrical & Electronic
Pawel M. Kaminski, Francesco Da Ros, Metodi P. Yankov, Henrik E. Hansen, Johan B. T. Ulvenberg, Christian K. Schou, Edson Porto da Silva, Tiago Sutili, Jose H. da Cruz Junior, Glauco C. C. P. Simoes, Anders T. Clausen, Soren Forchhammer, Rafael C. Figueiredo, Leif K. Oxenlowe, Michael Galili
Summary: The study focuses on providing lumped optical nonlinearity suppression using optical phase conjugation, allowing for increased transmission rate and reach. The design method can move beyond standard techniques and improve performance by carefully matching compensation structures to much longer transmission links, as demonstrated through numerical investigations and experimental demonstrations.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Thomas E. Maybour, Devin H. Smith, Peter Horak
Summary: A theoretical model for a dynamic Moire grating capable of producing improved slow and stopped light performance was investigated. By varying coupling strength in time, the Moire grating can significantly reduce group velocity in the slow light resonance while maintaining a wide bandwidth. This dynamic Moire grating could potentially realize bandwidth modulation and be implemented using an electro-optic grating with a quasistatic electric field in a poled chi((2)) nonlinear medium.
Article
Physics, Multidisciplinary
J. Mornhinweg, M. Halbhuber, C. Ciuti, D. Bougeard, R. Huber, C. Lange
Summary: We investigate the nonlinear response of tailor-cut light-matter hybrid states in a novel regime where the Rabi frequency induced by a coherent driving field and the vacuum Rabi frequency set by a cavity field are comparable to the carrier frequency of light. In this previously unexplored strong-field limit of ultrastrong coupling, subcycle pump-probe and multiwave mixing nonlinearities between different polariton states violate the normal-mode approximation while ultrastrong coupling remains intact. We anticipate that such custom-cut nonlinearities of hybridized elementary excitations will facilitate nonclassical light sources, quantum phase transitions, or cavity chemistry with virtual photons.
PHYSICAL REVIEW LETTERS
(2021)
Article
Construction & Building Technology
Shing Mei Chiew, Izni Syahrizal Ibrahim, Mohd Azreen Mohd Ariffin, Han-Seung Lee, Jitendra Kumar Singh
Summary: This study investigates the impact of light incidence angle, fibre spacing, and fibre diameter on the light transmittance of Light-transmitting Concrete (LTC). The results show that increasing fibre diameter increases light transmittance, while increasing fibre spacing and light incidence angle decrease light transmittance. A fibre diameter of 2 mm has the most significant effect on light transmittance.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Biochemistry & Molecular Biology
Marek Litniewski, Alina Ciach
Summary: The study using molecular dynamics simulations reveals that a binary mixture of oppositely charged particles with short-range attraction and repulsion near a substrate forms alternating layers or bilayers. The number, orientation, and structure of these layers can vary with different substrates and gas densities. The thickness of the adsorbed film can be significant for strong attraction, and an equal amount of particles from both components are adsorbed in all cases due to long-range attraction.
Article
Mathematics
Riccardo Adami, Filippo Boni, Simone Dovetta
Summary: This paper investigates the existence of ground states for the nonlinear Schrodinger equation on star graphs with two subcritical focusing nonlinear terms. The results show that if the standard nonlinearity is stronger than the pointwise nonlinearity, ground states exist only for small mass. Conversely, if the pointwise nonlinearity prevails, ground states exist only for large mass. All ground states are radial and have the same restriction to each half-line, coinciding with a soliton tail. Moreover, when the two nonlinearities are of the same size, the existence of ground states is independent of the mass value and is only valid in graphs with a small number of half-lines.
JOURNAL OF FUNCTIONAL ANALYSIS
(2022)
Article
Optics
Tao Li, Jing Hu, Xiaoling Ji
Summary: This study focuses on the imaging and focusing characteristics of partially coherent light pulses (PCLPs) propagating through a thin lens in nonlinear self-focusing media. Analytical formulas for image distance, image size, and focal length are derived. The results indicate that the time delay of the image distance is dependent on the spatial coherence of the light, while the time delay of the image size is not. Additionally, it is found that PCLPs have advantages in avoiding optical damage as the incident distance or thin lens focal length increases or the initial pulse width decreases when the pulse peak power is fixed.
OPTICS COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Ihar Babushkin, Alvaro Jimenez Galan, Jose Ricardo Cardoso de Andrade, Anton Husakou, Felipe Morales, Martin Kretschmar, Tamas Nagy, Virgilijus Vaicaitis, Liping Shi, David Zuber, Luc Berge, Stefan Skupin, Irina A. Nikolaeva, Nikolay A. Panov, Daniil E. Shipilo, Olga G. Kosareva, Adrian N. Pfeiffer, Ayhan Demircan, Mark J. J. Vrakking, Uwe Morgner, Misha Ivanov
Summary: This paper discusses the possible time delay of electron tunnelling from an atom and presents an all-optical method to study this phenomenon. The research shows that the tunnelling wavepacket undergoes reshaping as it emerges from the tunnelling barrier and moves away from the core, and this can be complemented by measuring the Brunel radiation emitted by the tunnelling electrons.
Article
Instruments & Instrumentation
E. Prost, V. Loriot, E. Constant, I. Compagnon, L. Berge, F. Lepine, S. Skupin
Summary: This study presents a THz platform using air plasma as a broadband source and air biased coherent detection for THz field. The setup is characterized by numerical simulations and measurements, confirming the effectiveness of the technique and demonstrating its application in THz spectroscopy of water vapor and a polystyrene sample.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Multidisciplinary Sciences
O. Finke, J. Vabek, M. Nevrkla, N. Bobrova, O. Hort, M. Jurkovic, M. Albrecht, A. Jancarek, F. Catoire, S. Skupin, J. Nejdl
Summary: One of the main challenges in efficiently generating high-order harmonics in long neutral-gas targets is achieving phase-matching conditions. The issue lies in the fact that the driving laser is unable to sufficiently ionize the medium due to plasma defocusing. In order to improve phase-matching, we propose a method of pre-ionizing the gas using a weak capillary discharge. Through experimental demonstrations in argon and krypton with an 800 nm femtosecond laser, we have successfully shown this mechanism for the first time. The ability to control phase-mismatch has been validated through an analytical model and numerical simulations of the entire generation process. Our method significantly increases the efficiency of harmonic generation and opens up possibilities for photon-hungry applications of these compact short-wavelength sources.
SCIENTIFIC REPORTS
(2022)
Article
Physics, Multidisciplinary
David Sohr, Jens Ulrich Thomas, Stefan Skupin
Summary: This paper explores the method of using curved line foci for cutting and edge shaping of glass sheets. By modifying the beam profile to avoid asymmetric laser modification of the glass sheet, a symmetric convex edge is successfully created on a 920 μm thick glass sheet.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Optics
A. Bartolo, N. Vigne, M. Marconi, G. Beaudoin, K. Pantzas, I Sagnes, G. Huyet, F. Maucher, S. V. Gurevich, J. Javaloyes, A. Garnache, M. Giudici
Summary: This study demonstrates that large-aspect-ratio VECSELs can operate in the spatiotemporal mode-locking regime. The emitted pulses have specific spatial profiles and temporal localization, which are important for studying spatiotemporal dynamics and multidimensional control of light.
Article
Mathematics, Applied
A. B. Steinberg, F. Maucher, S. V. Gurevich, U. Thiele
Summary: To analyze pattern formation and phase transitions in Bose-Einstein condensates, an approximate mapping from the nonlocal Gross-Pitaevskii equation to a phase field crystal model is presented. The simplified model allows for exploration of bifurcations and phase transitions through numerical path continuation. The existence of localized states in the PFC approximation is demonstrated, and the impact of higher-order nonlinearities on the bifurcation diagram is discussed.
Article
Physics, Multidisciplinary
Alexandre Stathopulos, Stefan Skupin, Luc Berge
Summary: This paper addresses the role of delayed Kerr nonlinearity associated with stimulated rotational Raman scattering on intense ultrashort two-color filaments with elliptical polarization in gases, and examines its impact on the generation of optical frequencies and terahertz frequencies. The study finds that the nonlinearity associated with stimulated Raman scattering strongly affects the dynamics of laser filaments and modifies the overall pulse spectral content, particularly altering the THz spectra during filamentation propagation. Differences between linearly and circularly polarized two-color pump pulses are discussed.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Physics, Multidisciplinary
Emilien Prost, Vincent Loriot, Eric Constant, Isabelle Compagnon, Luc Berge, Franck Lepine, Stefan Skupin
Summary: This paper presents a two-color air plasma-based broadband THz generation and subsequent air-biased coherent detection (ABCD) of the THz field. Both the source and detection systems are characterized experimentally and numerically, showing excellent agreement between measured and simulated signals. It is found that accurately interpreting the experimental measurements requires modeling the entire optical setup, including various pump distortions, and considering geometrical effects in the ABCD scheme.
EUROPEAN PHYSICAL JOURNAL-SPECIAL TOPICS
(2023)
Article
Multidisciplinary Sciences
J. Sanchez-Baena, C. Politi, F. Maucher, F. Ferlaino, T. Pohl
Summary: Usually, increasing the temperature of a system leads to disorder but supersolids can show the opposite trend. Here, the authors discuss the observation of a supersolid phase in a dilute gas of dysprosium atoms by increasing their temperature. They find surprising deviations from the general phenomenology in the finite-temperature physics of dipolar quantum fluids and describe how heating a dipolar superfluid can induce a phase transition to a supersolid state with a broken translational symmetry. The observation of this effect in experiments on ultracold dysprosium atoms opens the door for exploring the unusual thermodynamics of dipolar quantum fluids.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Atomic, Molecular & Chemical
Yong-Chang Zhang, Fabian Maucher
Summary: This paper discusses the effects of quantum fluctuations on dipolar Bose-Einstein condensates (BECs) and introduces variational approaches to approximately determine the phase diagrams for trapped dipolar BECs. Two-dimensional symmetry breaking occurs in the plane perpendicular to the polarisation axis, and approximate expressions for small modulation amplitudes are derived and compared to rigorous numerics.
Article
Optics
Mattias Rasmussen, Oliver Nagy, Stefan Skupin, Alexandre Stathopulos, Luc Berge, Peter Uhd Jepsen, Binbin Zhou
Summary: The frequency-resolved terahertz beam profile characteristics of a two-color air-plasma THz source were investigated in the broadband frequency range (1-15 THz). The THz focal spot size was found to be strongly frequency-dependent, which is important for accurate measurement in nonlinear THz spectroscopy. The transition between the solid and hollow beam profile was identified, and the conical emission patterns were observed across the 1-15 THz range.
Proceedings Paper
Engineering, Electrical & Electronic
David Sohr, Jens Ulrich Thomas, Stefan Skupin
Summary: The use of Airy-Gauss beam for cutting and shaping glass sheets is studied, with research on plasma ignition in the side lobes of the beam and surface damage issues, providing numerical results on creating symmetric convex edge on a 920 μm thick glass sheet with simple optical adjustments.
LASER-BASED MICRO- AND NANOPROCESSING XVI
(2022)
Article
Physics, Multidisciplinary
Ole A. Iversen, Thomas Pohl
Summary: The propagation of light through an optical waveguide chirally coupled to three-level quantum emitters is studied, and it is shown that additional laser coupling can control the properties of bound states and even eliminate them, thus transforming a focusing nonlinearity into a repulsive photon-photon interaction. The quantum dynamics of multiple photons reveal a fragmentation of incident uncorrelated light fields into regular trains of single photons.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Materials Science, Multidisciplinary
Valentin Walther, Lida Zhang, Susanne F. Yelin, Thomas Pohl
Summary: Excitons in a semiconductor monolayer can reflect resonant light with high efficiency, and this study investigates the nonlinear optical properties of these excitonic mirrors. The research shows that interactions between excitons can generate highly nonclassical light, with two different scenarios described. The findings suggest promising applications in quantum photonics at the individual photon level.
Article
Optics
M. Gaudesius, Y-C Zhang, T. Pohl, R. Kaiser, G. Labeyrie
Summary: This paper describes the three-dimensional simulation of spatiotemporal instabilities in a magneto-optical trap using a kinetic model. The model shows qualitative agreement with experimentally observed instability thresholds and regimes, providing important insights into the complex mechanism at work.
