Article
Chemistry, Analytical
Laurent Le Coq, Nicolas Mezieres, Paul Leroy, Benjamin Fuchs
Summary: This study focuses on the three-dimensional characterization of antenna far field patterns at terahertz frequencies, addressing the challenges of accurately measuring the phase of the electric field. Models and procedures to estimate errors caused by mechanical and electrical issues are proposed, with experimental validation demonstrating the effectiveness of the approach.
Article
Optics
Muhammad Anisuzzaman Talukder, Paul Dean, Edmund H. Linfield, A. Giles Davies
Summary: This study introduces a THz QCL heterostructure designed to emit two resonant photons from each electronic relaxation between two same-parity states, predicting a significant enhancement of light intensity compared to conventional THz QCL structures through simulations.
Editorial Material
Nanoscience & Nanotechnology
Miriam S. Vitiello, Luigi Consolino, Massimo Inguscio, Paolo De Natale
Summary: QCL is the most powerful chip-scale source of optical frequency combs, allowing mode proliferation with large quantum efficiencies. THz QCL FCs have promising applications in various fields due to their high quantum efficiency and ease of integration.
Article
Optics
Richa Gupta, Gaurav Varshney, R. S. Yaduvanshi
Summary: A circularly polarized dielectric resonator antenna has been implemented and numerically analyzed for terahertz applications, achieving CP response in the THz frequency range using a composite of different deformed geometries silicon based DRs. The proposed antenna provides high gain and radiation efficiency in THz frequencies, with an axial ratio of 4.67% and an impedance bandwidth of 3.72%.
Article
Physics, Applied
Li Wang, Tsung-Tse Lin, Mingxi Chen, Ke Wang, Hideki Hirayama
Summary: This study demonstrates the crucial role of compositional interdiffusion at interfaces in GaAs/AlGaAs alternating superlattices for developing high temperature terahertz quantum cascade lasers. By growing GaAs/Al0.3Ga0.7As superlattices using molecular beam epitaxy, an aluminum interdiffusion width of 0.95 nm is estimated. Incorporating this interdiffusion as a design parameter improves the maximum operating temperature of the laser by 20 K. The study also introduces an independent self-energy function based on axial correlation length to quantify the effects of interdiffusion scattering on electron dynamics.
APPLIED PHYSICS EXPRESS
(2023)
Article
Optics
Yuan-Yuan Li, Fang-Yuan Zhao, Yu Ma, Wei-Jiang Li, Jun-Qi Liu, Feng-Qi Liu, Jun-Wei Luo, Jin-Chuan Zhang, Shen-Qiang Zhai, Ning Zhuo, Li-Jun Wang, Shu-Man Liu
Summary: By integrating a suitable lens with a well-designed QCL array, multiple spatially-separated beams with controlled divergence angles and focusing efficiency are achieved. This method demonstrates excellent emission characteristics and multi-wavelength spectra at 77 K temperature.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Physics, Applied
M. Jaidl, N. Opacak, M. A. Kainz, D. Theiner, B. Limbacher, M. Beiser, M. Giparakis, A. M. Andrews, G. Strasser, B. Schwarz, J. Darmo, K. Unterrainer
Summary: This paper demonstrates terahertz quantum cascade lasers realized in ideal ring resonators without discontinuities, achieved by mounting the rings upside down on a silicon substrate using a die-bonding technique. The lasers emit light around 3.8 THz, show reduced threshold current densities, and exhibit frequency comb formation.
APPLIED PHYSICS LETTERS
(2022)
Article
Optics
M. Shalini, M. Ganesh Madhan
Summary: The proposed graphene-based patch antenna is suitable for THz applications, achieving circular polarization by modifying the linear polarized antenna design. It offers advantages of simple fabrication, high gain, and high efficiency.
Article
Physics, Multidisciplinary
Qiangqiang Guo, Jinchuan Zhang, Fengmin Cheng, Ning Zhuo, Shenqiang Zhai, Junqi Liu, Lijun Wang, Shuman Liu, Fengqi Liu
Summary: We demonstrate an anti-symmetric sampled grating (ASG) for mode selection in a quantum cascade laser (QCL). The -1st mode wavelength of the laser has been blue-shifted more than 75 nm compared to an ordinary sampled grating laser, while maintaining constant periodicities in the base grating and sample grating. This ASG structure is fabricated using holographic exposure and optical photolithography, providing flexibility, repeatability, and cost-effectiveness.
Article
Nanoscience & Nanotechnology
Tong Sun, Zhongyang Bai, Zhaoying Li, Yongshan Liu, Yaxuan Chen, Fan Xiong, Linliang Chen, Yong Xu, Fan Zhang, Dong Li, Junze Li, Weisheng Zhao, Tianxiao Nie, Lianggong Wen
Summary: Broadband spintronic terahertz radiation is efficiently generated by spin-to-charge current conversion in a ferromagnetic/nonmagnetic heterostructure. This study proposes a set of femtosecond laser-driven versatile spintronic terahertz devices by integrating meta-antenna structures with W/CoFeB/Pt nanolayer stacks. These monolithic integrated devices exhibit spintronic terahertz wave emission, spectral modulation, and polarization manipulation simultaneously.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Optics
Yunfei Xu, Yongqiang Sun, Weijiang LI, Yu Ma, Ning Zhuo, Junqi Liu, Jinchuan Zhang, Shenqiang Zhai, Shuman Liu, Lijun Wang, Fengqi Liu
Summary: This article reports on a phase-locked array scheme of terahertz quantum cascade laser (THz QCL) that utilizes Talbot effect. By adjusting the absorbing boundary width of each ridge in the array, stable operation and power amplification of THz QCL are achieved.
Review
Quantum Science & Technology
Miriam Serena Vitiello, Paolo De Natale
Summary: Quantum cascade lasers (QCLs) demonstrate the generation of artificial materials with tailor-made properties through quantum design, featuring intrinsic linewidths near the quantum limit and spontaneous phase-locking. Operating at terahertz frequencies, QCLs show important technological performances and have promising future prospects in the field of quantum technologies.
ADVANCED QUANTUM TECHNOLOGIES
(2022)
Article
Optics
W. E. I. J. I. A. N. G. LI, Y. U. Ma, Y. U. N. F. E. Xu, J. U. N. Q. Liu, L. I. J. U. N. Wang, N. I. N. G. Zhuo, Q. U. A. N. Y. O. N. G. Lu, J. I. N. C. H. U. A. N. Zhang, S. H. E. N. Q. I. A. N. G. Zhai, S. H. U. M. A. N. Liu, F. E. N. G. Q. Liu
Summary: This study reports on the terahertz (THz) quantum cascade lasers operating in continuous-wave (CW) mode with a frequency above 5 THz. The researchers achieved excellent performance by using a hybrid quantum design with a bridged bound-to-continuum structure at 5 THz, resulting in a smaller leakage current and higher population inversion efficiency. By designing and fabricating a graded metallic sampled distributed feedback grating in the waveguide, they successfully realized the first single-mode THz quantum cascade laser operating at 5.13 THz in CW mode. The laser achieved a maximum single-mode optical power of approximately 48 mW at 15 K with a side-mode suppression ratio above 24 dB. This research will attract great interest in spectroscopy applications above the 5 THz range for THz quantum cascade lasers.
PHOTONICS RESEARCH
(2022)
Article
Optics
J. Riepl, J. Raab, P. Abajyan, H. Nong, J. R. Freeman, L. H. Li, E. H. Linfield, A. G. Davies, A. Wacker, T. Albes, C. Jirauschek, C. Lange, S. S. Dhillon, R. Huber
Summary: The study investigates the ultrafast two-dimensional spectroscopy of a free-running THz QCL using high-field THz pulses, revealing strong nonlinear effects and the nonlinear polarization dynamics of QCL laser transitions. The data uncover extremely short gain recovery times and nonlinear effects, showing potential for future applications.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Andreas Ericsson, Daniel Sjoberg, Giampiero Gerini, Cecilia Cappellin, Frank Jensen, Peter Balling, Nelson J. G. Fonseca, Peter de Maagt
Summary: An antenna system using CPSS was proposed to achieve CP equivalent to LP reflectors. The CPSS characteristics were computed through full-wave simulations and reflector surface shapes were optimized in TICRA POS software. Experimental results highlighted challenges in producing electrically large multilayer curved surfaces.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2021)
Article
Physics, Applied
Attique Dawood, SaeJune Park, Rowan Parker-Jervis, Chris Wood, Lianhe H. Li, Edmund H. Linfield, Alexander Giles Davies, John Cunningham, Oleksiy Sydoruk
Summary: We demonstrate the engineering of low-terahertz range plasmonic spectra in two-dimensional electron systems by modifying their geometry. By comparing the results of two devices, one with a rectangular channel and the other with a trapezoidal channel, we show the different characteristics of each device. This research highlights the potential of modifying the channel geometry to obtain different spectra in experiments and has important implications for the design of novel terahertz-range devices.
JOURNAL OF PHYSICS D-APPLIED PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Suraj P. Khanna, Satish Singh, C. K. Suman, Nandan Kumar
Summary: The write-once-read-many (WORM) memory effect is reported in a polyethylene terephthalate (PET)-metal fiber spun electroconductive yarn with a tex of 19.68 and a ratio of 80:20. The yarn sample exhibits typical WORM memory behavior with a high OFF/ON resistance ratio and long retention period. The charge conduction mechanism changes from electronic to ionic as the polyester fibers undergo phase transition. Additionally, the sample can be reset to its initial high-resistive state through intentional mechanical perturbation.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Optics
Muhammad Anisuzzaman Talukder, Paul Dean, Edmund H. Linfield, A. Giles Davies
Summary: This study introduces a THz QCL heterostructure designed to emit two resonant photons from each electronic relaxation between two same-parity states, predicting a significant enhancement of light intensity compared to conventional THz QCL structures through simulations.
Article
Multidisciplinary Sciences
Renato Juliano Martins, Emil Marinov, M. Aziz Ben Youssef, Christina Kyrou, Mathilde Joubert, Constance Colmagro, Valentin Gate, Colette Turbil, Pierre-Marie Coulon, Daniel Turover, Samira Khadir, Massimo Giudici, Charalambos Klitis, Marc Sorel, Patrice Genevet
Summary: The article introduces an advanced LiDAR technology that achieves a large field of view and high frame rate by using ultrafast low FoV deflectors and large area metasurfaces, enabling simultaneous peripheral and central imaging zones. The use of this technology with advanced learning algorithms offers potential improvements in perception and decision-making processes of ADAS and robotic systems.
NATURE COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
Suraj P. Khanna, Satish Singh, C. K. Suman, Nandan Kumar, Alok Dabi
Summary: Multilevel non-volatile resistive switching behavior is observed in electronic textile, displaying write-once-read-many (WORM) memory behavior and allowing conduction modulation using a remote current-bias write/input stimulus. Anisotropic current spreading in the textile can be utilized for selective memory writing and emulating neuron-like behavior. The textile also exhibits the reset WORM or ReWORM effect.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Nanoscience & Nanotechnology
Laurent Boulley, Thomas Maroutian, Paul Goulain, Andrey Babichev, Anton Egorov, Lianhe Li, Edmund Linfield, Raffaele Colombelli, Adel Bousseksou
Summary: We demonstrate low temperature deposition conditions for VO2 phase change material that are compatible with III-V semiconductors used in optoelectronic applications. The VO2 coated thin films grown on GaAs exhibit a 50% change in optical reflectivity and a significant variation in electric conductivity between insulating and metallic states. We also study the functionalization of mid-infrared QCLs with VO2 layers to engineer their laser emission properties.
Article
Physics, Applied
C. Song, M. Salih, L. H. Li, J. Mangeney, J. Tignon, A. G. Davies, E. H. Linfield, S. Dhillon
Summary: By using thin metallic side-absorbers, researchers have successfully suppressed higher-order transverse modes in Terahertz quantum cascade lasers (THz QCLs), allowing the lasers to operate solely on the fundamental transverse mode without sacrificing high power outputs. This breakthrough opens up opportunities for investigating nonlinear THz physical phenomena using THz QCLs as pump sources.
APPLIED PHYSICS LETTERS
(2023)
Article
Optics
Elisa Riccardi, Valentino Pistore, Seonggil Kang, Lukas Seitner, Anna De Vetter, Christian Jirauschek, Juliette Mangeney, Lianhe Li, A. Giles Davies, Edmund H. Linfield, Andrea C. Ferrari, Sukhdeep S. Dhillon, Miriam S. Vitiello
Summary: By using multilayer graphene saturable absorbers, we have successfully demonstrated a self-starting miniaturized short pulse terahertz laser, which utilizes an original device architecture with surface patterning in the entire cavity of a double-metal semiconductor 2.30-3.55 THz wire laser. This compact, all-electronic, all-passive, and inexpensive configuration achieves self-starting pulsed emission with 4.0 ps-long pulses.
Article
Chemistry, Analytical
Khushboo Singh, Aparajita Bandyopadhyay, Karl Bertling, Yah Leng Lim, Tim Gillespie, Dragan Indjin, Lianhe Li, Edmund H. Linfield, A. Giles Davies, Paul Dean, Aleksandar D. Rakic, Amartya Sengupta
Summary: In order to reduce water consumption in agriculture, photonics-based hydration sensing technology has been widely used for non-contact, non-invasive mapping of liquid water in plants. In this study, terahertz (THz) range sensing techniques were employed to map liquid water in leaves of Bambusa vulgaris and Celtis sinensis. Two complementary techniques, THz time-domain spectroscopic imaging and THz quantum cascade laser-based imaging, were utilized. The results provide detailed spatial and temporal information about hydration dynamics and dehydration effects on leaf structure.
Article
Chemistry, Multidisciplinary
Jia Chen, Dapeng Wang, Guangyuan Si, Rongxin Zhang, Yongsop Hwang, Xinjian Wang, Jiaxin Zheng, Mengzhe Shen, Qian Wang, Jiao Lin
Summary: Metasurfaces consisting of planar subwavelength structures are used in emerging technologies for their small size and compatibility with nanofabrication techniques. However, the reduced dimensionality of metasurfaces poses challenges for adapting methods used in conventional optics. This work demonstrates the experimental realization of phase-coded multiplexing using a metasurface, and also achieves code-based all-optical routing. These findings have important implications for integrated optics and photonic data processing.
ADVANCED MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Craig S. Knox, Matthew T. Vaughan, Andrew D. Burnett, Mannan Ali, Satoshi Sasaki, Edmund H. Linfield, Alexander Giles Davies, Joshua R. Freeman
Summary: In this study, we investigated the properties of THz conductivity spectra in the ternary alloy Bi2(Te(1-x)Sex)3 as a function of selenium fraction, x, and temperature. Our findings suggest that preferential ordering in the x = 1/3 phase of Bi2(Te(1-x)Sex)3 leads to a red-shift in the Eu1 phonon on cooling, compared to binary Bi2Te3 and Bi2Se3 samples. We also observed coupling between the Eu1 phonon and an electronic continuum at low temperatures, regardless of the alloy's stoichiometry or the Hall mobility of the topological insulator crystal. These results highlight the importance of these optical modes in the transport properties of this ternary alloy.
Article
Materials Science, Multidisciplinary
A. Beckert, M. Grimm, R. Hermans, J. R. Freeman, E. H. Linfield, A. G. Davies, M. Muller, H. Sigg, S. Gerber, G. Matmon, G. Aeppli
Summary: The crystal field energy levels and magnetic moments of the insulating rare-earth magnet LiY1-xHoxF4 were investigated, including the hyperfine corrections, and the far-infrared, low-temperature refractive index of the material was determined.
Proceedings Paper
Engineering, Electrical & Electronic
M. Binois, R. Duvigneau, M. Elsawy, P. Genevet, S. Kadhir, S. Lanteri, N. Lebbe
Summary: The past decade has seen a significant amount of work on developing thin metamaterials for controlling the wavefront of light and achieving planar photonics, also known as flat optics or metaoptics. Metasurfaces, which are arrays of subwavelength-spaced and optically thin optical elements, are at the core of these discoveries and enable new physics and phenomena different from those observed in three-dimensional bulk metamaterials. This research presents recent activities and achievements in metasurface design, including numerical characterization approaches suited to the multiscale nature of metasurfaces and inverse design strategies for discovering non-classical metasurface configurations. The study involves collaboration between computational scientists and physicists and applies the proposed numerical methodologies to the design of phase gradient metasurfaces and light front shaping metalenses, with some fabricated metasurfaces experimentally characterized to confirm their predicted performances.
2022 3RD URSI ATLANTIC AND ASIA PACIFIC RADIO SCIENCE MEETING (AT-AP-RASC)
(2022)
Article
Materials Science, Multidisciplinary
N. Lebbe, S. Lanteri, S. Y. Golla, P. Genevet
Summary: This research addresses the theoretical problem of electromagnetic field transition conditions at conformal interfaces to achieve surface-topography-dependent transmitted and reflected fields. The analysis is supported by two-and three-dimensional finite-element simulations, providing a solid theoretical framework for designing metasurfaces for cloaking, wearable optics, and next-generation freeform imaging systems.
Review
Physics, Applied
Qinghua Song, Xingsi Liu, Cheng-Wei Qiu, Patrice Genevet
Summary: Metasurfaces made of optically thin and subwavelength structure arrays enable the tailoring of light properties, resulting in innovative optical components. Vectorial metasurface holography, which controls both the intensity and polarization distributions of light, has attracted significant attention due to its promising applications in photonics and optics.
APPLIED PHYSICS REVIEWS
(2022)
