Article
Physics, Particles & Fields
Wei-Liang Qian, Kai Lin, Xiao-Mei Kuang, Bin Wang, Rui-Hong Yue
Summary: In this work, the authors study the black hole light echoes and their connection with the quasinormal modes. They find that the time-domain correlator naturally acquires the echo feature through the analysis of quasinormal modes and characteristic parameters of null geodesics. The dominant contributions to the light echoes come from those in the eikonal limit. Numerical demonstrations are provided for Schwarzschild black holes, and a potential difference between results obtained using geometric-optics approach and black hole perturbation theory is pointed out for Kerr spacetimes. The study has important implications for astrophysics.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Optics
Mansi Baliyan, Naveen K. Nishchal
Summary: This paper introduces an efficient method for generating scalar and vector modes of Bessel-Gaussian (BG) beams using a spatial light modulator (SLM) encoded with a computer-generated phase-only mask. The combination of a phase-only hologram corresponding to the transmission function of an axicon with a spatial phase plate (SPP) is used to convert a Gaussian field into a phase singular beam with an azimuthally varying spiral wavefront structure, achieving non-diffracting BG beams. A compact experimental setup is proposed for generating BG fields with homogeneous and spatially varying polarization distributions across the transverse plane. Scalar BG beams are generated by modulating the combined phase patterns of the axicon and SPP using the SLM. Vector BG beams are generated through dual-passes from the SLM in two special cases: azimuthally and radially polarized inhomogeneous distributions. A non-interferometric technique using a single SLM divided into two halves is utilized to encode scalar BG beams with orthogonal phase structures into orthogonal components of incoming light for vector BG beam generation.
Article
Physics, Multidisciplinary
Eduardo Zubizarreta Casalengua, Elena del Valle, Fabrice P. Laussy
Summary: In this paper, we discuss the two-photon correlations from side peaks formed when a two-level system emitter is coherently driven with a detuning between the driving source and the emitter. We combine the theories of frequency-resolved photon correlations and homodyning to provide a neat picture compatible with perturbative two-photon scattering. This has implications for controlling, enhancing, and exploring new regimes of multiphoton emission. We also propose a way to demonstrate the quantum coherent nature of the process solely through photoluminescence observations.
Article
Engineering, Manufacturing
Mingman Sun, He Cheng, Pooria Golvari, Stephen M. Kuebler, Xiaoming Yu, Meng Zhang
Summary: This study simulated two-photon polymerization process and validated the model reliability. The research showed that using fewer but higher energy pulses is more energy-efficient under lower pulse energy, while energy waste occurs under higher pulse energy.
ADDITIVE MANUFACTURING
(2022)
Article
Engineering, Mechanical
Xingpei Wu, Jiankang Huang, Jing He, Shien Liu, Guangyin Liu, Ding Fan
Summary: Researchers have utilized a three-dimensional laser vision method to monitor the oscillation mode of a weld pool, and employed the Bessel equation for analysis. Experimental results have shown that laser dot matrix images are crucial for identifying the oscillation mode of a weld pool.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2021)
Article
Optics
Will McCutcheon
Summary: Systems of coupled cavity modes have the potential to provide bright quantum optical states of light, but backscattering and geometrical defects in microring resonators can affect system performance. Through establishing a model and numerical simulations, we studied these issues and evaluated efficiency in various photon schemes.
Article
Optics
Gaurav Shukla, Dariya Salykina, Gaetano Frascella, Devendra Kumar Mishra, Maria Chekhova, Farit Ya Khalili
Summary: In this theoretical study, we investigate the possibility of broadening the phase range of sub-shot-noise sensitivity in a squeezing-enhanced linear interferometer by implementing detection in both output ports and optimizing the combination of detector outputs. This modification allows the interferometer to maintain phase sensitivity independent of the operation point and remain unaffected by laser technical noise, similar to the standard dark port regime. Additionally, by using phase-sensitive amplifiers before each detector, the sensitivity can also tolerate detection loss.
Article
Optics
Xiao-Bo Hu, Benjamin Perez-Garcia, Valeria Rodriguez-Fajardo, Raul Hernandez-Aranda, Andrew Forbes, Carmelo Rosales-Guzman
Summary: One of the key features of quantum entanglement is its invariance under local unitary transformations during free-space propagation, but we have identified an exception using a carefully engineered vectorial light field where the local nonseparability between spatial and polarization degrees dramatically decays to zero while preserving the global nonseparability. Our results reveal novel properties of classically entangled modes and indicate the need for new measures of nonseparability for such vectorial fields, opening the door for new applications in structured light.
PHOTONICS RESEARCH
(2021)
Article
Physics, Multidisciplinary
Ganael Roeland, Srinivasan Kaali, Victor Roman Rodriguez, Nicolas Treps, Valentina Parigi
Summary: In this study, a general framework for single-photon addition on multimode states of light via parametric down conversion (PDC) processes is developed. The analytical conditions for single-mode and mode-selective photon addition are identified. Numerical results for photon addition in PDC process at near-infrared and telecommunications wavelengths are presented.
NEW JOURNAL OF PHYSICS
(2022)
Article
Engineering, Mechanical
Jincheng Shi, Liangwei Zeng, Junbo Chen
Summary: Nonlinear lattices can stabilize multidimensional solitons in self-focusing systems, preventing critical and supercritical collapse, and have applications in many optical experiments.
NONLINEAR DYNAMICS
(2023)
Article
Optics
Ya Guo, Lu Bai, Yankun Wang, Penghui Gao, Lixin Guo
Summary: Rytov theory is used to analyze the spiral spectrum and orbital angular momentum crosstalk effects of partially coherent Bessel Gaussian localized wave in anisotropic atmospheric turbulence. The research shows that the propagation quality of OAM mode carried by BGLW is superior to traditional BG beam in turbulence, and suggests that increasing the input pulse width and wavelength can reduce the effects of atmospheric turbulence on OAM modal detection probability. This study provides a theoretical basis for performance evaluations and parameters optimization in practical OAM-based optical communication technology.
Article
Quantum Science & Technology
Arpad Kurko, Peter Domokos, Andras Vukics, Thomas Baekkegaard, Nikolaj Thomas Zinner, Jozsef Fortagh, David Petrosyan
Summary: In this study, we investigate the emission of photons from a coherently prepared atomic ensemble in an elongated harmonic trap with normal density distribution. By determining the parameters of paraxial optics, we match the mode geometry of the emitted radiation and collect it optimally into an optical waveguide.
EPJ QUANTUM TECHNOLOGY
(2021)
Article
Optics
Erse Jia, Chen Xie, Na Xiao, Francois Courvoisier, Minglie Hu
Summary: In the femtosecond two-photon polymerization (2PP) experimental system, a multichannel interferometric wavefront sensing technique is adopted to solve the issue of optical aberrations, resulting in the successful fabrication of high-quality microtube arrays.
CHINESE OPTICS LETTERS
(2023)
Article
Physics, Multidisciplinary
Stefano Longhi
Summary: A unique feature of non-Hermitian systems is the skin effect, which refers to the edge localization of a considerable number of bulk-band eigenstates in a lattice with specific boundaries. Unlike Bloch waves in Hermitian systems, the skin modes in non-Hermitian systems are normalizable eigenstates originating from the intrinsic non-Hermitian point-gap topology of the Bloch band energy spectra. Additionally, these skin modes exhibit a fascinating property known as self-healing, where they can reconstruct their shape after being scattered by a space-time potential.
PHYSICAL REVIEW LETTERS
(2022)
Article
Neurosciences
Cleophace Akitegetse, Thomas Charland, Mireille Quemener, Charles Gora, Veronique Rioux, Michel Piche, Yves De Koninck, Martin Levesque, Daniel C. Cote
Summary: This study presents a two-photon light sheet microscope that overcomes artifacts caused by the geometry of the light sheet. By using a specific beam, the microscope achieves high resolution and a large field of view, making it suitable for fast imaging of large specimens.
Article
Optics
Steven Johnson, Alex McMillan, Stefan Frick, John Rarity, Miles Padgett
Summary: A limitation of free-space optical communications is the ease of interception, which can be overcome by hiding information within background optical noise. We demonstrate image transfer over free-space using a photon-pair source emitting two correlated beams. One beam contains image information with added noise, while the other correlated beam serves as a heralding trigger to differentiate the image signal from background noise. The system utilizes spontaneous parametric down-conversion and a gated intensified camera to extract the image from the noise.
Article
Optics
Keshaan Singh, Angela Dudley, Andrew Forbes
Summary: Measuring and correcting wavefront aberrations is crucial in various fields, and our approach using a digital micro-mirror device allows for dynamic extraction of wavefronts with high resolution and tuneable sensitivity. We verified its capability by extracting common aberrations, phase screens, and lens phases under static and dynamic conditions. This setup also enables convenient real-time adaptive correction and is versatile, cheap, fast, accurate, broadband, and polarization invariant.
Article
Optics
Bereneice Sephton, Isaac Nape, Chane Moodley, Jason Francis, Andrew Forbes
Summary: Single-pixel quantum ghost imaging exploits non-local photon spatial correlations to image objects using light that has not interacted with them, reducing detection to a single pixel through intelligent spatial scanning with projective masks. Despite facing challenges in extending to complex amplitude objects, we discover that the necessary interference for phase retrieval is naturally embedded in correlation measurements formed from traditional projective masks in bi-photon quantum ghost imaging. With this, we develop a simple method to obtain the complete phase and amplitude information of complex objects and demonstrate unambiguous reconstruction of objects with spatially varying structures and complex amplitudes. This technique could be a significant step towards imaging the phase of light-sensitive structures in biological matter.
Article
Quantum Science & Technology
Markus Rambach, Akram Youssry, Marco Tomamichel, Jacquiline Romero
Summary: Quantum state tomography is an essential component in quantum computation and communication, but standard techniques often struggle with changing states and environmental noise. We propose a matrix-exponentiated gradient (MEG) tomography method that can dynamically track and update the estimated density matrix efficiently, even with noisy data. Experimental implementation on a qutrit system encoded in photons demonstrates fidelities of approximately 95% in different scenarios.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Andrew Forbes
Summary: This article reflects on the progress made in both fundamental science and applications in connecting light's orbital angular momentum (OAM) with its spatial structure over the past 30 years. A recent trend has been the direct creation of OAM from lasers, offering potential for tunable, compact, and high-power sources of OAM light. This tutorial-style review provides a summary of the basics of OAM, its creation at the source, significant advancements, the current state-of-the-art, and the remaining challenges.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Editorial Material
Nanoscience & Nanotechnology
Andrew Forbes, Leerin Perumal
NATURE NANOTECHNOLOGY
(2023)
Article
Optics
Justin Harrison, Andrew Forbes, Darryl Naidoo
Summary: In this study, we demonstrate the power amplification of low-power higher-order Laguerre-Gaussian modes using a novel in-line dual-pass master oscillator power amplifier. Our approach achieves a gain factor of up to 17x, corresponding to an overall enhancement of 300% in amplification compared to a single-pass output configuration, while preserving the beam quality of the input mode. Computational simulations confirm these findings and show excellent agreement with the experimental data.
Article
Optics
Justin Harrison, Wagner Tavares Buono, Andrew Forbes, Darryl Naidoo
Summary: In this study, higher-order (l = 2) orbital angular momentum (OAM) beams were generated and power amplified using a compact end-pumped Nd:YAG Master-Oscillator-Power-Amplifier (MOPA) design. We analyzed the thermally-induced wavefront aberrations of the Nd:YAG crystal and showed that natural astigmatism leads to the splitting of vortex phase singularities. By engineering the Gouy phase, we achieved an amplified vortex purity of 94% and an amplification enhancement of up to 1200% in the far field. Our comprehensive theoretical and experimental investigation is valuable for communities working on high-power applications of structured light, including communications and materials processing.
Article
Optics
Keshaan Singh, Pedro Ornelas, Angela Dudley, Andrew Forbes
Summary: Researchers demonstrate the dynamics of optical skyrmions within a magnetic field by engineering them using superpositions of Bessel-Gaussian beams. The skyrmionic form changes during propagation, exhibiting controllable periodic precession. Through a full Stokes analysis of the optical field, the local precession manifests as global beating between different skyrmion types while maintaining the invariance of the Skyrme number. Numerical simulation shows the potential for extending this approach to create time varying magnetic fields, providing a powerful analogue to solid state systems.
Article
Optics
Justin Harrison, Andrew Forbes, Darryl Naidoo
Summary: MOPA systems are widely used in laser development to increase the optical power of laser emissions. This study presents a novel approach for accurate modeling of the multimode fiber-coupled pump beam using a diffractive optical element. The theoretical model is experimentally validated and shows excellent agreement with predicted output powers.
Article
Optics
Leerin Perumal, Andrew Forbes
Summary: Laser beam shaping is a popular topic that has recently regained attention due to advancements in structured light and modern implementation tools. This tutorial focuses on using digital micro-mirror devices (DMDs) for fast, affordable, and dynamic laser beam shaping. It provides a theoretical overview, practical guidance, and showcases the effectiveness of the approach through various case studies, including monochromatic and broadband light.
Article
Optics
Isaac Nape, Bereneice Sephton, Pedro Ornelas, Chane Moodley, Andrew Forbes
Summary: Structured light has emerged as a hot topic, offering new states of light, enhanced functionality, and a modern toolbox for fundamental science. By structuring light as single photons and entangled states, high dimensional quantum states can be encoded using spatial modes, enabling tests of quantum mechanics and improved information processing. This tutorial outlines the basics of high dimensional quantum states expressed in spatial modes and explains how to create, control, and detect such states, focusing on transverse spatial modes like orbital angular momentum and pixel modes. Examples of applications, from communications to imaging, are also highlighted.
Article
Physics, Applied
Cade Peters, Mitchell Cox, Alice Drozdov, Andrew Forbes
Summary: In this study, we investigated the invariance and distortion of vectorial light through atmospheric turbulence. Although the amplitude and polarization structure were severely distorted, the non-separability between these two degrees of freedom remained invariant. This result provides conclusive evidence that invariance and distortion are not mutually exclusive and has implications for classical and quantum communication in free space.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Konstantin Y. Bliokh, Ebrahim Karimi, Miles J. Padgett, Miguel A. Alonso, Mark R. Dennis, Angela Dudley, Andrew Forbes, Sina Zahedpour, Scott W. Hancock, Howard M. Milchberg, Stefan Rotter, Franco Nori, Sahin K. Ozdemir, Nicholas Bender, Hui Cao, Paul B. Corkum, Carlos Hernandez-Garcia, Haoran Ren, Yuri Kivshar, Mario G. Silveirinha, Nader Engheta, Arno Rauschenbeutel, Philipp Schneeweiss, Juergen Volz, Daniel Leykam, Daria A. Smirnova, Kexiu Rong, Bo Wang, Erez Hasman, Michela F. Picardi, Anatoly Zayats, Francisco J. Rodriguez-Fortuno, Chenwen Yang, Jie Ren, Alexander B. Khanikaev, Andrea Alu, Etienne Brasselet, Michael Shats, Jo Verbeeck, Peter Schattschneider, Dusan Sarenac, David G. Cory, Dmitry A. Pushin, Michael Birk, Alexey Gorlach, Ido Kaminer, Filippo Cardano, Lorenzo Marrucci, Mario Krenn, Florian Marquardt
Summary: Structured waves are found in all areas of wave physics, both classical and quantum, where the wavefields are inhomogeneous and cannot be approximated by a single plane wave. These complex wavefields with inhomogeneities are crucial in various fields such as nanooptics, photonics, quantum matter waves, acoustics, water waves, etc. This Roadmap surveys the role of structured waves in wave physics, providing background, current research, and anticipating future developments.
Article
Optics
Cade Peters, Pedro Ornelas, Isaac Nape, Andrew Forbes
Summary: Nonseparability in classical and quantum states of light can be measured using concurrence and spatially resolved. The study explores local and nonlocal entanglement using vectorial structured light and its quantum analog. This research has significant implications for understanding coherence and polarization in vectorial light and quantum entangled states for imaging.
