Article
Optics
Shujing Li, Linguo Li
Summary: In this paper, a novel quantum key distribution protocol RRDQPS-QKD-OCS is proposed, which uses one decoy state and odd coherent states for outstanding performance in terms of higher key generation rate and longer transmission distance. The protocol only requires a single decoy state to approach the asymptotic limit performance achieved by using infinite decoy states in RRDQPS-QKDOCS.
Article
Telecommunications
Steven Kisseleff, Symeon Chatzinotas
Summary: This article describes a multi-user quantum key distribution (QKD) system based on free-space optics (FSO) in a terrestrial environment. FSO-QKD is heavily affected by obstacles in the signal path, leading to decoherence and other harmful effects. Trusted nodes (TNs) are introduced to the QKD network to avoid performance degradation. However, with no alternative signal routes, the same TN relays both the classical data and quantum key, making it a potential target for eavesdropping. To address this issue, the use of a trusted reconfigurable intelligent surface (RIS) is explored, which passively reflects classical signals and manipulates them to align with the distributed keys. Numerical simulations with multiple FSO-QKD users and an eavesdropper demonstrate that the proposed concept provides high levels of data protection even in the event of a successful attack on the trusted RIS and complete key acquisition by the eavesdropper.
IEEE COMMUNICATIONS LETTERS
(2023)
Article
Quantum Science & Technology
Li-Guo She, Chun-Mei Zhang
Summary: Reference-frame-independent quantum key distribution (RFI-QKD) enables the generation of secret keys even in the presence of unknown and slowly drifting reference frames. This paper introduces modified coherent states (MCS) to implement decoy-state RFI-QKD, which improves the secret key rate and transmission distance.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Engineering, Electrical & Electronic
Sha Zhu, Zhijie Chen, Yunxin Wang, Ya Jin, Kunpeng Zhai, Yunping Bai, Jun Tan, Peiyuan Wan, Xu Liu, Wei Li, Ning Hua Zhu
Summary: This paper proposes and demonstrates a photonic multi-format background-free binarily modulated microwave signal generator using a single dual-polarization dual-parallel Mach-Zehnder modulator. The generator features good reconfiguration and switchability, capable of generating microwave signals with multiple modulation methods.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Carlo Caputo, Mario Simoni, Giovanni Amedeo Cirillo, Giovanna Turvani, Maurizio Zamboni
Summary: This article presents the development of a QKD simulator based on low-computational-cost models. It focuses on polarization-based QKD setups with faint laser sources while considering realistic eavesdropping attacks and non-idealities. The simulator can output the Mean Photon Number (MPN) at the receiver, Quantum Bit Error Rate (QBER), and secure key rate.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Physics, Multidisciplinary
Robert Trenyi, Marcos Curty
Summary: Coherent-one-way quantum key distribution (QKD) promises to distribute secret keys over long distances with a simple setup, but recent studies show that its secret key rate only scales at most quadratically with the system's transmittance, making it unsuitable for long distance transmission.
NEW JOURNAL OF PHYSICS
(2021)
Article
Optics
Xu Hua Cao, Xiao Jie Fan, Ming Li, Ning Hua Zhu, Wei Li
Summary: In this study, we propose a novel photonic approach to generate reconfigurable multi-frequency multiple binary modulation formats microwave signals using a dual-polarization dual-drive Mach-Zehnder modulator. By setting the proper formats of coding signals, various modulation formats of microwave signals can be generated successfully without changing the system structure.
OPTICS COMMUNICATIONS
(2024)
Article
Engineering, Electrical & Electronic
Yunpeng Zhang, Yunbin Wu, Haiyun Xia
Summary: This article introduces a coherent Doppler wind lidar technology with high spatial and temporal resolution, using phase-shift keying and Mach-Zehnder modulator to improve measurement efficiency and system stability, and demonstrating its principle and practical application value through theoretical analysis and experiments.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Optics
Jing Dong, Tao Wang, Lang Li, Peng Huang, Guihua Zeng
Summary: This paper proposes a frame synchronization scheme based on weak coherent states in quantum key distribution (QKD). The synchronization performance is analyzed under different conditions and compared with other synchronization sequences. An optical experiment verifies the feasibility of the scheme under low signal-to-noise ratio (SNR). This efficient and noise-tolerant scheme can provide technical support for weak-coherent-state-based QKD and future quantum network construction.
Article
Quantum Science & Technology
Le Han, Yang Yu, Wenhao Lu, Ke Xue, Wenting Li, Shengmei Zhao
Summary: In this paper, a new protocol is proposed in the field of quantum key distribution to improve the secure key rate and practicality. Simulation results show significant performance improvement compared to existing protocols, and the proposed protocol also exhibits excellent performance when considering finite data size and statistical fluctuation.
QUANTUM INFORMATION PROCESSING
(2022)
Article
Mathematics
Milica Petkovic, Goran T. T. Dordevic, Jaroslaw Makal, Zvezdan Marjanovic, Gradimir V. V. Milovanovic
Summary: In this paper, an analytical framework is developed for the design and analysis of fronthaul/backhaul links in new generation mobile networks using free-space optical technology. The average symbol error probability of a coherent FSO system is analyzed considering receiver hardware imperfections and the influence of pointing errors and atmospheric turbulence. The results show that imperfect phase error compensation has a more critical impact on the SEP under weaker turbulence conditions and higher order modulation formats. The presented analytical tools can be used to estimate the tolerable value of phase noise standard deviation for a given SEP, which is an important parameter in designing the phase-locked loop filter in the receiver.
Article
Quantum Science & Technology
Shyam R. Sihare
Summary: The research paper presents a new approach to multi-party quantum key distribution using variational quantum eigensolvers. It aims to establish secure communication among multiple parties in a quantum network. The paper outlines a comprehensive framework and provides mathematical formulations and experimental designs.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Optics
Wagdy A. Alathwary, Essam S. Altubaishi
Summary: In this article, the performance of a heterodyne detection system with adaptive modulation is investigated in a strong turbulence channel modeled by the Gamma-Gamma distribution. The expressions for spectral efficiency (SE) and bit-error-rate (BER) are derived, and a new exact expression for BER is presented using bivariate Fox's H-function (BFHF). The results demonstrate the improvement in SE achieved by the adaptive system when the modulation level is selected based on the channel state. Additionally, the adaptive system is extended to a parallel-branches system with maximum ratio combining, showing further improvement in SE as the number of branches increases.
OPTICS AND LASER TECHNOLOGY
(2024)
Article
Quantum Science & Technology
Jasminder S. Sidhu, Shuro Izumi, Jonas S. Neergaard-Nielsen, Cosmo Lupo, Ulrik L. Andersen
Summary: In this work, a new decoding scheme for quadrature phase-shift encoded signals is proposed and experimentally demonstrated, surpassing the standard quantum limit and outperforming previously known nonadaptive detectors at low input powers. Unlike existing approaches, the receiver only utilizes linear optical elements and on-off photodetection, avoiding the challenging feed-forward operations that limit communication transmission rates and can be readily implemented with current technology.
Article
Chemistry, Multidisciplinary
Xinxin Gao, Ze Gu, Qian Ma, Wen Yi Cui, Tie Jun Cui, Chi Hou Chan
Summary: Driven by the demands for compact interconnects and fast information transfer, research on spoof plasmonic metamaterials has been focused on achieving individual modulation of amplitude or phase at single frequencies due to structural limitations. This study proposes and experimentally demonstrates an ultra-thin reprogrammable modulator consisting of a spoof surface plasmonic polariton (SSPP) waveguide and spoof localized surface plasmon (SLSP) resonators, allowing independent control of amplitude and phase of surface waves. By manipulating the SSPP waveguide and SLSP resonators in real-time, various programmable modulations such as amplitude-shift keying, phase-shift keying, quadrature amplitude modulation, and frequency-shift keying can be achieved. Measurement results confirm the potential applications of the reprogrammable plasmonic metamaterial in integrated circuits and communication systems.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Optics
Nikolay A. Kalinin, Elena A. Anashkina, Gerd Leuchs, Alexey Andrianov
Summary: An efficient optical scheme for coherent combining of radiation from a multicore fiber (MCF) output is proposed. The scheme is simple, using only basic optical elements, and can be applied to any number of MCF cores. It has achieved high efficiency and good beam quality in proof-of-concept experiments and numerical modeling.
Article
Optics
Aaron Z. Goldberg, Andrei B. Klimov, Hubert DeGuise, Gerd Leuchs, Girish S. Agarwal, Luis L. Sanchez-Soto
Summary: The study demonstrates that the multipoles associated with the density matrix can be unambiguously determined from intensity moments, and they have correct transformation properties, making them natural variables for dealing with various problems in the quantum domain.
Article
Chemistry, Physical
Dante Maria Aceti, Emil Filipov, Liliya Angelova, Lamborghini Sotelo, Tommaso Fontanot, Peyman Yousefi, Silke Christiansen, Gerd Leuchs, Stanislav Stanimirov, Anton Trifonov, Ivan Buchvarov, Albena Daskalova
Summary: Ultra-short laser combined with nanoparticles synthesis provides a novel approach for enhancing commercially pure titanium surfaces. This single-step process allows for surface structuring and oxidation, as well as the synthesis of silver nanoparticles. The presence of silver nanoparticles and micro/nano-structured surface topography enables the realization of antimicrobial surfaces on medical devices.
Article
Optics
Luis L. Sanchez-Soto, Juan J. Monzon, Gerd Leuchs
Summary: This study examines the response of a Fabry-Perot interferometer to a monochromatic point source and calculates the anti-caustics resulting from successive internal reflections. These anti-caustics are found to be a family of ellipsoids or hyperboloids of revolution, which allows for a geometric interpretation of the Fabry-Perot interferometer's operation and facilitates comparison with other seemingly unrelated setups such as Young's double slit experiment.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION
(2022)
Article
Mathematics
Arseny A. Sorokin, Gerd Leuchs, Joel F. Corney, Nikolay A. Kalinin, Elena A. Anashkina, Alexey Andrianov
Summary: Researchers propose a method to generate highly squeezed multiphoton states using chalcogenide and tellurite soft glass fibers with 2-micron continuous-wave light. Numerical simulations show that quantum noise squeezing stronger than -15 dB can be achieved with appropriate fiber lengths.
Article
Optics
A. Andrianov, N. A. Kalinin, A. A. Sorokin, E. A. Anashkina, L. L. Sanchez-Soto, J. F. Corney, G. Leuchs
Summary: Bright squeezed light can be generated in optical fibers using the Kerr effect, but nonconservative effects degrade the squeezing. This study analyzes two-mode polarization squeezing, which is robust against perturbations and can be generated in a polarization-maintaining fiber. Numerical optimization and comparison with experimental results are performed using an advanced model of quantum pulse evolution in the fiber.
Article
Chemistry, Multidisciplinary
Anna A. A. Vasileva, Daria V. V. Mamonova, Yuri V. V. Petrov, Ilya E. E. Kolesnikov, Gerd Leuchs, Alina A. A. Manshina
Summary: We propose an efficient method for creating stable electrocatalytically active nanocomposites by combining in situ synthesis of polyaniline (PANI) with laser-induced deposition of metal nanoparticles (NPs). The use of the substrate during the formation of multi-metallic nanoparticles (MNP) solves the problem of particle loss from the electrode surface. The PANI/AgPt nanocomposites show the best activity and stability in electrocatalysis.
Article
Chemistry, Multidisciplinary
Anna A. Vasileva, Daria V. Mamonova, Vladimir Mikhailovskii, Yuri V. Petrov, Yana G. Toropova, Ilya E. Kolesnikov, Gerd Leuchs, Alina A. Manshina
Summary: This paper presents a new methodology for creating 3D ordered porous nanocomposites using anodic aluminum oxide template with polyaniline (PANI) and silver NPs. The approach involves in situ synthesis of polyaniline on templates and laser-induced deposition of Ag NPs on the pore walls. The developed structures demonstrated effectiveness as non-enzymatic electrochemical sensors for glucose detection in a concentration range crucial for medical applications.
Article
Physics, Applied
M. A. T. Butt, P. Roth, G. K. L. Wong, M. H. Frosz, L. L. Sanchez-Soto, E. A. Anashkina, A. V. Andrianov, P. Banzer, P. St. J. Russell, G. Leuchs
Summary: Polarization-preserving fibers cannot preserve two nonorthogonal states required for quantum communication. We propose an alternative scheme using helically twisted photonic crystal fibers to enable polarization encoding in the continuous-variable regime. Experimental results show that appropriate nonorthogonal modes in the polarization-preserving fiber do not fully scramble over the full Poincare sphere, but remain on a great circle, forming a one-dimensional protected subspace that can be parametrized by a single variable. This allows for more efficient measurements of quantum excitations in nonorthogonal modes.
PHYSICAL REVIEW APPLIED
(2023)
Article
Physics, Multidisciplinary
Gerd Leuchs, Margaret Hawton, Luis L. Sanchez-Soto
Summary: This paper discusses the concept of emptiness in space and suggests changing the traditional view. It explores how vacuum fluctuations determine the values of permittivity and permeability by modeling their dynamic response using three-dimensional harmonic oscillators.
Article
Chemistry, Multidisciplinary
Gulia Bikbaeva, Anna Pilip, Anastasia Egorova, Ilya Kolesnikov, Dmitrii Pankin, Kirill Laptinskiy, Alexey Vervald, Tatiana Dolenko, Gerd Leuchs, Alina Manshina
Summary: Photopharmacology is an important and booming research area that requires new drugs with simultaneous photoswitching and pharmacophore functions. In this study, CQDs@phosphonate nanohybrids were introduced for the first time, which can inhibit butyrylcholinesterase and control inhibition degree through laser irradiation. This research has significant implications for the field of photopharmacology.
Article
Quantum Science & Technology
Nikolay Kalinin, Thomas Dirmeier, Arseny A. Sorokin, Elena A. Anashkina, Luis L. Sanchez-Soto, Joel F. Corney, Gerd Leuchs, Alexey V. Andrianov
Summary: This paper reports on a new all-fiber setup for generating polarization squeezed light. The setup is composed of passive elements only, making it simple, stable, and easy to set up. More than 5 dB of directly measured squeezing is achieved over long periods of time without any adjustments. Therefore, this new scheme provides a robust and easy-to-set-up method for obtaining squeezed light applicable to various applications.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Quantum Science & Technology
Nicolas Fabre, Andrei B. Klimov, Gerd Leuchs, Luis L. Sanchez-Soto
Summary: This study proposes a new method to calculate the Wigner function for systems with SU(1,1) symmetry by utilizing the properties of the parity operator. It also presents an optical experiment that enables point-by-point sampling of the Wigner function.
AVS QUANTUM SCIENCE
(2023)
Article
Physics, Fluids & Plasmas
E. S. Efimenko, A. Bashinov, A. A. Muraviev, V. D. Volokitin, I. B. Meyerov, G. Leuchs, A. M. Sergeev, A. Kim
Summary: This article studies the vacuum breakdown caused by 10-PW-class lasers in the optimal configuration of laser beams. By using 3D PIC simulations, the threshold of vacuum breakdown is calculated to be about 10 PW. The dynamics of particles and their trajectories contributing the most to vacuum breakdown in highly inhomogeneous fields are examined in detail. The analysis also reveals the concentric toroidal layers in the electron-positron plasma distribution during the avalanche stage, and proposes a way to experimentally identify the vacuum breakdown process based on the angular distribution of charged particles and gamma photons.
Article
Optics
Aaron Z. Goldberg, Markus Grassl, Gerd Leuchs, Luis L. Sanchez-Soto
Summary: It is now widely accepted that true quantum correlations can exist even without entanglement. The presence of quantumness can be verified by averaging a state's bipartite entanglement properties over all physically relevant modal decompositions. Extremal states for this measure have been investigated.
