Article
Physics, Multidisciplinary
Tony Jin, Tristan Gautie, Alexandre Krajenbrink, Paola Ruggiero, Takato Yoshimura
Summary: In the study of quench dynamics in free fermionic systems, it was found that the higher the correlation in the initial state, the slower the transport speed. This relationship was both qualitatively and quantitatively analyzed using proper measures of correlations and transport 'speed'. Additionally, an exact solution for fermions on a lattice and an explicit solution for a wider class of physically relevant initial states in the continuous case supported this finding.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Jung-Wan Ryu, Martina Hentschel
Summary: Classic quantum chaos originated from the idea of combining nonlinear physics and Hermitian quantum mechanics, while recent advancements in non-Hermitian models have enriched the field. Low-dimensional effective matrix models have proven to be a useful tool for studying the physical properties of systems in a semi-quantitative manner. This article focuses on two realizations of non-Hermitian physics in mesoscopic systems: spiral optical microcavities and parity-time symmetric ladder lattices.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2022)
Article
Engineering, Electrical & Electronic
Taher M. Bazan
Summary: This paper presents the first mathematical investigation of using a single inline optical amplifier in a 2-D time-spreading wavelength-hopping (TW) code division multiple access (OCDMA) system. The research focuses on the amplifier input power range, encoder/decoder loss levels, and power budget, finding that the single inline optical amplifier is effective for low-loss encoders but only supports a specific number of simultaneous users in higher capacity systems.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Benshan Wang, Thomas Ferreira de Lima, Bhavin J. Shastri, Paul R. Prucnal, Chaoran Huang
Summary: Digital signal processing (DSP) has played a crucial role in optical communication systems, but the limitations of DSP chips have hindered the deployment of computationally costly algorithms. Photonic neural networks offer a promising solution to these challenges, with better performance and lower power consumption. This study proposes a photonic recurrent neural network (RNN) capable of processing optical signals and effectively addressing fiber nonlinearities in the photonic domain, achieving reduced power consumption and latency compared to traditional DSP chips.
IEEE JOURNAL OF SELECTED TOPICS IN QUANTUM ELECTRONICS
(2023)
Article
Engineering, Electrical & Electronic
Ankita Jain, John. C. C. Cartledge
Summary: The impact of filtering impairments resulting from cascaded, wavelength selective switches is investigated for 32 Gbaud dual-polarization 64-ary quadrature amplitude modulation in the presence of transceiver noise. Training-sequence based adaptive equalization and pilot-aided carrier phase estimation are employed to cope with the combined effects of the transceiver-imposed limitation in achievable signal-to-noise ratio and the filtering-induced signal distortion. The implications of statistical variations in the overall filter frequency response are also assessed.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Shun Matsuo, Hiroyuki Uenohara
Summary: This study investigates all-optical wavelength conversion based on four-wave mixing in highly nonlinear fiber using pump lights generated from optical combs and SSB modulation. It achieves wide wavelength selectivity and highly precise frequency controllability. The experimental results show that the use of generated pump lights for FWM leads to clear constellations and low bit error rates.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Engineering, Electrical & Electronic
Weigang Hou, Pengxing Guo, Lei Guo, Xu Zhang, Hui Chen, Weichen Liu
Summary: This paper proposes O-Star, a scalable optical switching architecture for on-chip many-core systems. It utilizes hybrid mode and wavelength division multiplexing technology to enable non-blocking switching and parallel data transmission.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Diego Paiva Pires, Tommaso Macri
Summary: Understanding the connection between quantum coherence and non-Hermitian features is crucial for developing quantum technologies based on dissipative systems. Multiple quantum coherences (MQCs) are useful for probing equilibrium phase transitions in non-Hermitian systems and studying critical points for various paradigmatic non-Hermitian Hamiltonians. Experimental results demonstrate the unique phase transition characteristics revealed by MQCs in different models, with implications for non-Hermitian quantum sensing, quantum thermodynamics, and the non-Hermitian skin effect.
Article
Engineering, Electrical & Electronic
Xiuhua Yang, Dunzhu Xia, Jinhui Li, Qingbo Chu
Summary: This article proposes a novel micro-opto-electromechanical system (MOEMS) accelerometer sensor based on metal-insulator-metal (MIM) waveguide wavelength modulation. The device detects external acceleration vibration signals through a mechanical sensing system and utilizes the MIM waveguide in the optical sensing system to measure the displacement of the mechanical vibration component, causing a change in light wavelength. Simulation results demonstrate that this accelerometer sensor has high sensitivity and resolution, making it suitable for high-precision measurements.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Yuan Li, Chengcheng Wu, Peili He, Wei Li, Shaohua Yu, Ming Luo, Zhongshuai Feng, Muyang Mei, Qianggao Hu, Liyan Huang, Haitao Li
Summary: A detailed theoretical study is conducted on the nonlinear interference in same-wavelength bidirectional coherent optical fiber communication systems. It is found that in a bidirectional transmission system, the backward signal almost does not introduce additional nonlinear crosstalk to the forward signal due to the strong walk-off effect.
IEEE PHOTONICS JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Jochen Vanderspikken, Wouter Maes, Koen Vandewal
Summary: This article discusses the development of wavelength-selective organic photodetectors and their early applications and potential in optical imaging field. It compares key parameters of visible and near-infrared wavelength photodetectors and explores different organic detector approaches. Moreover, it emphasizes the importance of material development and device design.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Engineering, Electrical & Electronic
Matheus Sena, Pratim Hazarika, Caio Santos, Bruno Correia, Robert Emmerich, Behnam Shariati, Antonio Napoli, Vittorio Curri, Wladek Forysiak, Colja Schubert, Johannes K. K. Fischer, Ronald Freund
Summary: Efficient anomaly detection schemes are crucial for autonomous optical networks. Receiver-based digital signal processing can help locate defective devices and monitor network performance. This study explores the benefits of utilizing DSP-based longitudinal power estimation and wavelet-denoising tools for anomaly detection.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Physics, Multidisciplinary
Jayakrishnan M. P. Nair, Debsuvra Mukhopadhyay, G. S. Agarwal
Summary: In recent years, the importance of exceptional points in sensing linear perturbations has been recognized. Sensing anharmonicities is essential for controlling various semiclassical and quantum effects resulting from nonlinear interactions. A proposed sensing scheme utilizes coherence between two modes induced by a common vacuum to enhance the detection of very weak anharmonicities.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Electrical & Electronic
Yiran Ma, Luke Stewart, Julian Armstrong, Ian G. Clarke, Glenn Baxter
Summary: Wavelength Division Multiplexing (WDM) networks with reconfigurable optical add/drop multiplexers (ROADMs) play a crucial role in meeting increasing bandwidth and routing flexibility demands. The wavelength selective switch (WSS) is a key component in all commercial ROADM systems, with Liquid Crystal on Silicon (LCoS) technology dominating current installations. WSS designs are becoming more specialized for various applications.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Helene Wetter, Zlata Fedorova, Stefan Linden
Summary: Using evanescently coupled waveguides, we investigated the propagation of surface plasmon polaritons and observed plasmonic analogs of Bloch oscillations and the Wannier-Stark ladder.
Article
Physics, Multidisciplinary
Dong-Sheng Ding, Hannes Busche, Bao-Sen Shi, Guang-Can Guo, Charles S. Adams
Article
Optics
Yuechun Jiao, Nicholas L. R. Spong, Oliver D. W. Hughes, Chloe So, Teodora Ilieva, Kevin J. Weatherill, Charles S. Adams
Article
Physics, Multidisciplinary
Nicholas L. R. Spong, Yuechun Jiao, Oliver D. W. Hughes, Kevin J. Weatherill, Igor Lesanovsky, Charles S. Adams
Summary: This study demonstrates a collectively encoded quantum bit based on a single Rydberg excitation stored in an ensemble of N entangled atoms. Qubit rotations are performed by applying microwave fields, and coherent readout is achieved by mapping the excitation into a single photon. The results show that robust quantum information processing can be achieved via collective encoding using Rydberg polaritons.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Nourah F. Almuhawish, Shuying Chen, Lucy A. Downes, Matthew J. Jamieson, Andrew R. MacKellar, Kevin J. Weatherill
Summary: Polarization spectroscopy of excited state transition in room temperature rubidium vapor was investigated. Anisotropy in the atomic medium was induced by applying a circularly polarized coupling beam and probed by scanning a probe beam across the transition. Autler-Townes splitting observed at high coupling intensities is ideal for laser frequency stabilization.
Article
Education, Scientific Disciplines
James L. Maxwell, Ifan G. Hughes, Charles S. Adams
Summary: Researchers used two methods to measure the wavelength dependence of the Verdet constant of a terbium gallium garnet crystal, and found that although the white-light measurement method only requires one source, it is more prone to systematic errors than using multiple laser sources.
EUROPEAN JOURNAL OF PHYSICS
(2022)
Article
Physics, Multidisciplinary
Florian Christaller, Max Maeusezahl, Felix Moumtsilis, Annika Belz, Harald Kuebler, Hadiseh Alaeian, Charles S. Adams, Robert Loew, Tilman Pfau
Summary: We investigate the generation of high atomic densities using light-induced atomic desorption in a vapor cell. By pulsing an intense off-resonant laser on a sapphire-coated cell, we observe the desorption of atomic clouds from the internal surfaces. Time-resolved absorption spectroscopy reveals the evolution of atomic density, showing broadening and line shift of the atomic resonances, which are attributed to dipole-dipole interactions. These findings highlight the potential of fast switching of atomic density and dipolar interactions for future quantum devices based on excitation blockade.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Shuying Chen, Dominic J. Reed, Andrew R. MacKellar, Lucy A. Downes, Nourah F. A. Almuhawish, Matthew J. Jamieson, Charles S. Adams, Kevin J. Weatherill
Summary: This paper demonstrates a system of electrometry using laser spectroscopy to characterize THz signals, allowing for measurements of THz electric field amplitudes and providing a potential method for THz calibration. The system is relatively simple and cryogen-free, offering an alternative to calorimetric methods for calibration.
Article
Physics, Multidisciplinary
Dong-Sheng Ding, Zong-Kai Liu, Bao-Sen Shi, Guang-Can Guo, Klaus Molmer, Charles S. Adams
Summary: This research demonstrates the enhanced sensitivity of many-body critical systems to small variations in external parameters in a non-equilibrium Rydberg atomic gas. By quantifying the Fisher information, it is shown that many-body effects lead to a three orders of magnitude increase in sensitivity compared to single-particle systems.
Article
Optics
Lucy A. Downes, Daniel J. Whiting, C. Stuart Adams, Kevin J. Weatherill
Summary: We demonstrate a rapid readout technique for terahertz orbital angular momentum (OAM) beams using an atomic-vapor-based imaging method. The OAM modes are generated using phase-only transmission plates, and the beams are converted from terahertz to optical in an atomic vapor before being imaged using an optical CCD camera. By imaging through a tilted lens, we are able to observe the self-interferogram of the beams and directly read out the sign and magnitude of the azimuthal index. This technique allows for reliable and high-fidelity readout of OAM modes in low-intensity beams within 10 ms.
Article
Physics, Multidisciplinary
Alexander Guttridge, Daniel K. Ruttley, Archie C. Baldock, Rosario Gonzalez-Ferez, H. R. Sadeghpour, C. S. Adams, Simon L. Cornish
Summary: We demonstrate Rydberg blockade between a single Rb atom and a single RbCs molecule confined in optical tweezers due to charge-dipole interaction. The molecule is efficiently transferred to the rovibrational ground state and the separation between the atom and molecule is controlled using species-specific tweezers. Excitation dynamics are observed to be consistent with simulated interaction potentials, opening up possibilities for transferring quantum information between individually trapped molecules using Rydberg atoms.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Joshua P. Rogers, Liam A. P. Gallagher, Danielle Pizzey, Jon D. Pritchett, Charles S. Adams, Matthew P. A. Jones, Chris Hodges, Wolfgang Langbein, Stephen A. Lynch
Summary: In this study, even-parity Rydberg exciton states in cuprous oxide were investigated using second harmonic generation (SHG) spectroscopy. The coherently generated second harmonic was successfully isolated from lower-lying free and bound excitonic states, and the quantum defects of the S and D excitonic states associated with crystal symmetries were determined. Odd-parity P and F excitonic states were also observed. The SHG spectrum was found to be cut off at a lower principal quantum number compared to conventional one-photon spectroscopy measurements.
Article
Physics, Multidisciplinary
A. Skljarow, H. Kuebler, C. S. Adams, T. Pfau, R. Loew, H. Alaeian
Summary: Strong light-induced interactions between atoms are crucial for quantum information processing. In a dielectric environment, the scattering and light-induced dipolar interaction of atoms can be enhanced. By combining the high densities achievable in thermal atomic vapors with efficient coupling to a slot waveguide, researchers have achieved controlled and enhanced atom interactions. The experimental results are in agreement with simulations, paving the way for robust and scalable quantum nonlinear optics and all-optical quantum information processing at room temperature.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Physics, Multidisciplinary
Liam A. P. Gallagher, Joshua P. Rogers, Jon D. Pritchett, Rajan A. Mistry, Danielle Pizzey, Charles S. Adams, Matthew P. A. Jones, Peter Grunwald, Valentin Walther, Chris Hodges, Wolfgang Langbein, Stephen A. Lynch
Summary: Exciton-mediated coupling between microwave and optical fields has been observed in cuprous oxide at low temperatures. Rydberg excitonic states with different principal quantum numbers were observed using one-photon and two-photon spectroscopy. The absorption line shape and coherent second harmonic were found to be significantly affected by the addition of a microwave field near resonance with an excitonic state. The results are in agreement with a model based on intraband electric dipole transitions between Rydberg exciton states.
PHYSICAL REVIEW RESEARCH
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Shuying Chen, Dominic Reed, Lucy A. Downes, Andrew R. MacKellar, Nourah F. Almuhawish, Matthew J. Jamieson, Charles S. Adams, Kevin J. Weatherill
Summary: The Rydberg EIT and AT splitting in an atomic vapor cell can be used as novel methods for electric-magnetic field detection. By observing a linear trend between THz field amplitude and the frequency splitting of the absorption dips and EIT transmission peaks induced by the THz radiation, the Rydberg atomic measurement system can be a practical tool for THz field detection.
2021 46TH INTERNATIONAL CONFERENCE ON INFRARED, MILLIMETER AND TERAHERTZ WAVES (IRMMW-THZ)
(2021)
Article
Optics
Sofia Ribeiro, Thomas F. Cutler, Charles S. Adams, Simon A. Gardiner
Summary: The study investigates the collective scattering of coherent light from thermal alkali-metal vapor and develops a theoretical model to describe this phenomenon. The model, treating the atomic ensemble as radiating dipoles, shows good qualitative agreement with experimental results and suggests the possibility of exploring different photon statistics regimes through fine-tuning of experimental parameters.