Article
Optics
Yong Li, Fei Teng, Bo Yang, Zhihao Zhang, Yafei Zhao, Yufei Zhang
Summary: This study analyzes the noise characteristics of HC-PCF IFOG and establishes a model to determine the main noise sources as well as an optimization method for its parameters.
Article
Engineering, Electrical & Electronic
Wen Fan, Xuan She, Heliang Shen, Fei Huang, Ran Bi, Kan Chen, Xingfan Chen, Xiaowu Shu
Summary: In this article, a hollow-core photonic crystal fiber (HCPCF) ring resonator based on a spatial coupling method was proposed, with a small component size of 22 x 30 x 6 mm³. By using a 7-core photonic crystal fiber with a mode field diameter of 10μm, a ring resonator with a measured finesse of 18 and a low coupling loss of 0.41 dB was achieved. The practicality of the HCPCF gyro was enhanced by using a highly integrated free space silicon optical bench manufactured by deep silicon etching and tiny optical lens package technology. Moreover, the article investigates two important factors affecting the spatial optical coupling efficiency, lens type and fiber mode field size, providing instructive results for all spatial optical coupling systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Optics
Yan Li, Xuemei Yang, Xiangying Hao, Shun Wu
Summary: The unique design of hollow-core photonic crystal fibers (HC-PCFs) has attracted attention for its potential applications in gas sensing and spectroscopy. Understanding gas flow dynamics in fiber design is crucial for estimating evacuation or gas filling time, with experimental data supporting theoretical predictions in pressure decrease trends. Integration of a correction factor representing the fiber's hollow-core structure improved simulation results accuracy.
Article
Engineering, Electrical & Electronic
Jonas H. Osorio, Joao B. Rosolem, Fabio R. Bassan, Foued Amrani, Frederic Gerome, Fetah Benabid, Cristiano M. B. Cordeiro
Summary: Research achievements in hollow-core photonic crystal fibers technology have identified these fibers as excellent platforms for delivering high-power laser beams with minimal interaction with the fiber microstructure. Here, the utilization of a tubular-lattice hollow-core fiber as a promising platform for Power-over-Fiber systems is demonstrated, which expands the range of hollow-core fiber-based beam delivery applications. The experiments reported here identify hollow-core fibers as eligible candidates for next-generation Power-over-Fiber devices.
OPTICAL FIBER TECHNOLOGY
(2022)
Article
Crystallography
Md Nazmul Islam, Kusay Faisal Al-tabatabaie, Md Ahasan Habib, Sheikh Sharif Iqbal, Khurram Karim Qureshi, Eid M. Al-Mutairi
Summary: This study proposes a hexagonal-shaped hollow-core photonic crystal fiber-based edible oil sensor in the THz range and evaluates its performance through statistical analysis. The simulation results demonstrate that the sensor has high sensitivity and can effectively detect different types of edible oils under optimized geometric and operational conditions.
Article
Engineering, Electrical & Electronic
Di Chen, Shuhui Liu, Zhengqing Shen, Panting Niu, Wei Cheng, Feng Xu
Summary: This article introduces a respiration sensor based on the anti-resonant reflecting effect, which can accurately monitor breath patterns, peak expiratory flow, and temperature changes. The sensor is lightweight, cost effective, and suitable for monitoring patients during certain medical procedures.
IEEE SENSORS JOURNAL
(2023)
Article
Engineering, Electrical & Electronic
Yong You, Huiyi Guo, Mao Feng, Baiwei Mao, Huimin Shi, Jiangbing Du, Zhi Wang, Yan-Ge Liu
Summary: The characteristics of higher-order modes in a 7-cell HC-PBF were investigated, revealing the non-degenerate phenomenon of HE21. An optimized 7-cell HC-PBF supporting 6 modes was developed through theoretical analysis. Additionally, bending losses of all HOMs in the fiber were measured, with marked bending loss not observed even at a small bending radius of 0.5 cm, distinguishing it from a solid core four-mode fiber.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Optics
Foued Amrani, Jonas H. Osorio, Frederic Delahaye, Fabio Giovanardi, Luca Vincetti, Benoit Debord, Frederic Gerome, Fetah Benabid
Summary: The design of hollow-core photonic crystal fibres with hybrid-lattice cladding significantly reduces confinement loss and preserves single-mode operation, showing potential for next-generation optical fibres.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Crystallography
Wenxi Pei, Hao Li, Wei Huang, Meng Wang, Zefeng Wang
Summary: The rotational stimulated Raman scattering of hydrogen molecules in an all-fiber cavity based on hollow-core photonic crystal fibers was reported. By using a homemade 1064 nm pulsed fiber amplifier, rotational SRS was induced in the gas cavity, leading to the generation of a 1135 nm Stokes wave. The output characteristics were explored by adjusting the pulse width and repetition frequency of the pump source, while a theoretical model was established for comparison with experimental results, facilitating the application of gas Raman laser based on HC-PCFs.
Article
Chemistry, Analytical
Heliang Shen, Kan Chen, Kang Zou, Yijia Gong, Ran Bi, Xiaowu Shu
Summary: The novel system structure proposed for the resonant fiber optical gyroscope effectively solves the problem of length mismatch between rings and significantly reduces noise. Its sensitivity can approach the shot-noise-limited theoretical value with excellent noise suppression effects.
Article
Materials Science, Multidisciplinary
Revathi Senthil, Utkarsh Anand, Prabu Krishnan
Summary: A low confinement loss HC-PCF structure for liquid/gas-sensing applications is proposed and analyzed using COMSOL software. The structure offers high sensitivity and low confinement loss compared to existing PCFs, making it suitable for various sensing applications. The proposed PCF has a simple cladding structure that is easy to fabricate and offers improved relative sensitivity.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Computer Science, Information Systems
Yingning Wang, Yao Lu, Changjing Bao, Wenpu Geng, Yuxi Fang, Baiwei Mao, Zhi Wang, Yan-Ge Liu, Hao Huang, Yongxiong Ren, Zhongqi Pan, Yang Yue
Summary: The proposed hollow As2S3 ring-core photonic crystal fiber can support a wide range of OAM modes for stable transmission. Numerical analysis and simulation show that higher-order OAM modes have better tolerance to fiber bending, indicating potential for ultra-high capacity OAM mode division multiplexing in optical fiber communication systems.
Article
Crystallography
Jianhua Fu, Yifei Chen, Zhiyuan Huang, Fei Yu, Dakun Wu, Jinyu Pan, Cheng Zhang, Ding Wang, Meng Pang, Yuxin Leng
Summary: This study demonstrates how the spectral width of resonance-induced dispersive waves (DW) can be significantly broadened by plasma-driven blueshifting solitons, leading to the generation of broadband DW with multiple spectral peaks. The use of super-Gaussian windows to filter out the spectral peaks and the study of their time-domain characteristics using Fourier transform method reveals different time delays among the peaks. Furthermore, the broadband DW with multiple spectral peaks can be compressed to approximately 29 fs after proper dispersion compensation.
Article
Optics
Xiaobin Xu, Xin Yuan, Fuyu Gao, Xiaoyang Wang, Ningfang Song
Summary: This study proposed a low-noise Fabry-Perot interference-based method to measure the longitudinal uniformity of the core structure within a seven-cell hollow-core photonic bandgap fiber. Experimental results showed improved precision to subnanometer scale and a model was established to analyze the effect on fiber loss. Simulation results indicated a fiber loss of around 22.73 dB/km, consistent with practical values.
Article
Engineering, Electrical & Electronic
Eric Numkam Fokoua, Wenwu Zhu, Meng Ding, Zitong Feng, Yong Chen, Thomas D. Bradley, Gregory T. Jasion, David J. Richardson, Francesco Poletti, Radan Slavik
Summary: Hollow-core optical fibers convey light in air, showing remarkably low sensitivity of the propagation delay to temperature changes, especially in photonic bandgap type. The residual variation in propagation delay observed near the zero sensitivity wavelength has no apparent correlation to imposed temperature changes. Practical thermal stability of latency is limited by polarization mode dispersion, with strong polarization mode coupling observed in addition to birefringence.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Angelica Simbula, Riccardo Pau, Fang Liu, Luyan Wu, Stefano Lai, Alessandra Geddo-Lehmann, Alessio Filippetti, Maria A. Loi, Daniela Marongiu, Francesco Quochi, Michele Saba, Andrea Mura, Giovanni Bongiovanni
Summary: In this work, an ultrafast radiometric experiment is introduced to directly assess the radiative decay rate in perovskite thin films through a calibrated measurement of the instantaneous photoluminescence flux under pulsed laser excitation. The measured radiative decay rate is found to be significantly lower than expected and is attributed to the formation of a population of dark excitations, specifically large polarons. These results provide insights into the radiative and non-radiative carrier recombination processes in metal halide perovskites, as well as the photophysical basis to optimize device performances in this emerging class of semiconductors.
ENERGY & ENVIRONMENTAL SCIENCE
(2022)
Article
Biochemical Research Methods
Peter F. Stadler, Sebastian Will
Summary: This study introduces the concept of bi-alignments, which can be used to align sequence and structure similarity simultaneously. Using affine cost bi-alignments, efficient alignments of large proteins can be computed.
ALGORITHMS FOR MOLECULAR BIOLOGY
(2022)
Article
Education, Scientific Disciplines
Matteo Tuveri, Alessia Zurru, Daniela Fadda, Michele Saba
Summary: Active learning strategies and information technology-based pedagogies are increasingly used in academic courses, with peer-instruction and flipped classroom being prominent examples. These strategies have been shown to improve students' understanding and exam scores. The Covid-19 pandemic in 2020 and 2021 forced remote teaching, but also provided an opportunity to test online learning and flipped classroom concepts. Student feedback and achievement analyses confirm the effectiveness of flipped classroom in remote learning.
EUROPEAN JOURNAL OF PHYSICS
(2022)
Article
Chemistry, Physical
Noemi Landi, Elena Maurina, Daniela Marongiu, Angelica Simbula, Silvia Borsacchi, Lucia Calucci, Michele Saba, Elisa Carignani, Marco Geppi
Summary: Mixed-cation lead mixed-halide perovskites, especially TripleMix, show higher efficiency and stability in perovskite-based photovoltaics. The structure and dynamics of TripleMix were investigated using multinuclear solid-state nuclear magnetic resonance (SSNMR), revealing slower dynamics of both organic cations and halide anions, which may contribute to its high photovoltaic performances.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Instruments & Instrumentation
Minho Kwon, Aaron Holman, Quan Gan, Chun-Wei Liu, Matthew Molinelli, Ian Stevenson, Sebastian Will
Summary: We present a design and characterization of a cold atom source for strontium (Sr) using a two-dimensional magneto-optical trap (MOT) that is loaded directly from the atom jet of a dispenser. The atom flux of the source is characterized by measuring the loading rate of a three-dimensional MOT, which reaches loading rates of up to 10^8 atoms per second. This compact and low-power consumption setup addresses the challenge of reducing complexity in cold beam sources for Sr, making it important for applications in optical atomic clocks, quantum simulation, and computing devices based on ultracold Sr.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Astronomy & Astrophysics
Jiayi Sun, Adam K. Leroy, Eve C. Ostriker, Sharon Meidt, Erik Rosolowsky, Eva Schinnerer, Christine D. Wilson, Dyas Utomo, Francesco Belfiore, Guillermo A. Blanc, Eric Emsellem, Christopher Faesi, Brent Groves, Annie Hughes, Eric W. Koch, Kathryn Kreckel, Daizhong Liu, Hsi-An Pan, Jerome Pety, Miguel Querejeta, Alessandro Razza, Toshiki Saito, Amy Sardone, Antonio Usero, Thomas G. Williams, Frank Bigiel, Alberto D. Bolatto, Melanie Chevance, Daniel A. Dale, Jindra Gensior, Simon C. O. Glover, Kathryn Grasha, Jonathan D. Henshaw, Maria J. Jimenez-Donaire, Ralf S. Klessen, J. M. Diederik Kruijssen, Eric J. Murphy, Lukas Neumann, Yu-Hsuan Teng, David A. Thilker
Summary: We measured the empirical relationships between local star formation rate and properties of the star-forming molecular gas in 80 nearby galaxies. These relationships, known as star formation laws, aim to predict the local SFR surface density using different combinations of molecular gas surface density, galactic orbital time, molecular cloud free fall time, and interstellar medium dynamical equilibrium pressure. Our results show that these relationships have intrinsic scatter and the slope of the molecular Kennicutt-Schmidt relation remains roughly constant across different environments. The other relationships show variations in their slopes, suggesting systematic changes in star formation efficiency and pressure-to-SFR surface density ratio.
ASTROPHYSICAL JOURNAL LETTERS
(2023)
Article
Multidisciplinary Sciences
Angelica Simbula, Luyan Wu, Federico Pitzalis, Riccardo Pau, Stefano Lai, Fang Liu, Selene Matta, Daniela Marongiu, Francesco Quochi, Michele Saba, Andrea Mura, Giovanni Bongiovanni
Summary: This article discusses the photophysics of layered Ruddlesden-Popper perovskites and demonstrates their nature as free carrier semiconductors, with a unique and universal framework.
NATURE COMMUNICATIONS
(2023)
Article
Optics
Deokhwa Hong, Junghoon Lee, Jongmin Kim, Jong Heum Jung, Kyuhwan Lee, Seji Kang, Y. Shin
Summary: We have observed stationary turbulence in antiferromagnetic spin-1 Bose-Einstein condensates driven by a radio-frequency magnetic field. The injected energy from the magnetic driving causes the emergence of an irregular spin texture in the condensate. Under continuous driving, the condensate evolves into a nonequilibrium steady state with spin turbulence, while the low-energy scale of spin excitations minimally affects the sample's lifetime. When the driving strength is comparable to the system's spin interaction energy and quadratic Zeeman energy, the stationary turbulent state exhibits spin-isotropic features.
Article
Optics
Haneul Kwak, Jong Heum Jung, Y. Shin
Summary: When a superfluid flows past an obstacle at a certain critical velocity, quantized vortices can be formed in the wake. This study investigates the critical vortex shedding in a two-dimensional BEC and finds that the minimum critical velocity occurs when the obstacle's height is close to the condensate chemical potential. Numerical simulations reveal that the minimum critical velocity is a result of local density reduction and vortex pinning effect caused by the repulsive obstacle. The spatial distribution of superflow and the formation of vortex dipole at the critical strength are also examined.
Article
Optics
Jong Heum Jung, Y. Shin
Summary: We numerically investigate the dynamics of vortex generation in a two-dimensional, two-component Bose-Einstein condensate subjected to an oscillatory magnetic obstacle. We find that vortex generation exhibits two distinct critical dynamics with different spin circulations as the oscillating frequency increases. We also observe that vortex generation is suppressed for weak obstacles, in agreement with recent experimental results. The characteristic length scale of the vortex generation dynamics is determined by the spin healing length of the system.
Article
Chemistry, Multidisciplinary
Antonio Cappai, Claudio Melis, Daniela Marongiu, Francesco Quochi, Michele Saba, Francesco Congiu, Yihui He, Tyler J. Slade, Mercouri G. Kanatzidis, Luciano Colombo
Summary: This study reports anomalous thermal transport of Cs2NaYbCl6 double-halide perovskite above room temperature and provides a rational explanation. Calculations of phonon dispersion relations and scattering rates show that specific phonon group velocities and lifetimes increase at high temperatures. The combination of anharmonicity and other factors is responsible for the increase in lattice thermal conductivity, contrary to previous predictions. The proposed model accurately reproduces the experimental data.
Article
Optics
Tenzin Rabga, Yangheon Lee, Dalmin Bae, Myeonghyeon Kim, Y. Shin
Summary: We study the vortex nucleation dynamics in inhomogeneous atomic Bose gases quenched into a superfluid phase and investigate the dependence of the Kibble-Zurek (KZ) scaling exponent on the trap configuration. We observe the characteristic power-law scaling of the vortex number with the quench rate and enhanced vortex suppression in the outer regions, in agreement with the inhomogeneous Kibble-Zurek mechanism. However, the measured KZ scaling exponents deviate from the theoretical estimates and their trends as a function of the trap configuration are different from the prediction. Our study highlights the importance of a refined theoretical framework for understanding phase transition and defect formation in such inhomogeneous systems.
Article
Optics
Myeonghyeon Kim, Tenzin Rabga, Yangheon Lee, Junhong Goo, Dalmin Bae, Y. Shin
Summary: Investigated the defect suppression effect in an inhomogeneous trapped atomic Bose gas quenched into a superfluid phase. Found that spontaneous defect production is relatively more suppressed in the sample's outer region with higher atomic density gradient.
Article
Physics, Multidisciplinary
Aden Z. Lam, NiccolO Bigagli, Claire Warner, Weijun Yuan, Siwei Zhang, Eberhard Tiemann, Ian Stevenson, Sebastian Will
Summary: This article reports the creation of ultracold gases of bosonic Feshbach molecules of NaCs, which are formed from overlapping gases of Na and Cs using a Feshbach resonance. The crucial parameters such as molecule numbers and temperatures of the associated gases are obtained through experiments. This lays the foundation for the creation of degenerate gases of strongly dipolar NaCs molecules in their absolute ground state.
PHYSICAL REVIEW RESEARCH
(2022)
Article
Optics
Jeong Ho Han, Dalmin Bae, Y. Shin
Summary: This study describes a synthetic three-leg Hall ladder system with a tunable magnetic flux for neutral Yb-173 atoms in a one-dimensional optical lattice. The controllable magnetic flux is achieved through Raman couplings between spin states, and the quench dynamics of the system were investigated under various interleg link configurations, showing substantial damping in certain cases.
