Article
Optics
Kiran Ilyas, Qaisar Abbas Naqvi
Summary: The study focuses on utilizing multi-core silicon-rich nitride photonic integrated waveguides to fill the supercontinuum spectrum in the mid-IR region and generate tunable dispersive waves. By adjusting the gap spacing between cores, the dispersion profile of the waveguide can be engineered to achieve phase-matching within specific wavelength ranges.
Article
Engineering, Electrical & Electronic
Saleha Fatema, Md Borhan Mia, Sangsik Kim
Summary: In this study, a broadband near-zero dispersion was achieved in a thin silicon nitride waveguide array at near-infrared using multiple mode couplings, covering a spectral range of 1350-1900 nm. By engineering the dispersion of the waveguide array, an octave-spanning supercontinuum was numerically generated with a pump of 100 fs and 200 pJ. The concept of obtaining broadband near-zero dispersion through multiple mode couplings can be applied to other spectral regimes and material platforms by adjusting structural parameters to shift the positions of zero dispersion wavelengths.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Jing Jia, Zhe Kang, Qiangsheng Huang, Sailing He
Summary: We propose and numerically study a dual-coupled ridge waveguide structure in thin-film lithium-niobate-on-insulator (LNOI) for highly efficient, broadband, and flattened dispersive wave-enhanced supercontinuum generation in the mid-infrared region. By tailoring the dispersion profile using the proposed structure, the supercontinuum generation can be pumped by a mode-locked fiber laser in the telecommunication band. Numerical simulations show that a broadband dispersive wave covering the wavelength range of 1.92 to 3.55 μm with good spectral flatness can be achieved. This work provides a competitive candidate for efficient, broadband, and flattened mid-infrared spectrum generation with important applications in spectroscopy, metrology, and communication.
APPLIED SCIENCES-BASEL
(2022)
Article
Optics
Marek Vlk, Anurup Datta, Sebastian Alberti, Henock Demessie Yallew, Vinita Mittal, Ganapathy Senthil Murugan, Jana Jagerska
Summary: This study presents a mid-infrared integrated waveguide sensor that addresses some drawbacks of waveguide sensing in air, performing well in terms of optical interaction per unit length and achieving a detection limit of 7 ppm for acetylene.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Optics
Alberto Della Torre, Milan Sinobad, Remi Armand, Barry Luther-Davies, Pan Ma, Stephen Madden, Arnan Mitchell, David J. Moss, Jean-Michel Hartmann, Vincent Reboud, Jean-Marc Fedeli, Christelle Monat, Christian Grillet
Summary: Supercontinuum generation in a germanium-on-silicon waveguide was experimentally demonstrated, producing a mid-infrared supercontinuum covering nearly an octave. Numerical analysis attributed the current limit to free-carrier absorption, restricting further extension into the mid-IR region.
Article
Multidisciplinary Sciences
Yanmei Cao, Byoung-Uk Sohn, Hongwei Gao, Peng Xing, George F. R. Chen, Doris K. T. Ng, Dawn T. H. Tan
Summary: This study demonstrates the generation of supercontinuum in an ultra-silicon-rich nitride waveguide and reveals the high spectral coherence of the generated supercontinuum. The results indicate that pulses with high spectral coherence can be used for self-referencing applications, metrology, and imaging.
SCIENTIFIC REPORTS
(2022)
Article
Optics
Pierre Didier, Hedwig Knoetig, Olivier Spitz, Laurent Cerutti, Anna Lardschneider, Elie Awwad, Daniel Diaz-Thomas, A. N. Baranov, Robert Weih, Johannes Koeth, Enedikt Schwarz, Frederic Grillot
Summary: Space-to-ground high-speed transmission is crucial for global broadband network development. The use of mid-infrared wavelengths offers advantages like low atmospheric attenuation and resistance to inclement weather conditions. A proof-of-concept experiment demonstrates a full interband cascade system that achieves high-speed transmission around a wavelength of 4.18 μm.
PHOTONICS RESEARCH
(2023)
Article
Optics
Pan Wang, Jiapeng Huang, Shangran Xie, Johann Troles, Philip St J. Russell
Summary: This paper reports the generation of broadband mid-infrared supercontinuum lasers using As2S3-silica nanospike hybrid waveguides, as well as the fabrication and investigation of linearly tapered millimeter-scale waveguides for the first time. These waveguides exhibit broader spectra, improved spectral coherence, long-term stability, and water resistance, offering an alternative route for generating broadband mid-IR supercontinua with applications in frequency metrology and molecular spectroscopy, especially in humid and aqueous environments.
PHOTONICS RESEARCH
(2021)
Article
Computer Science, Information Systems
Jing Jia, Zhe Kang, Sailing He
Summary: A suspended thin-film lithium-niobate-on-insulator nano-waveguide was designed for tunable mid-infrared dispersive wave generation. By controlling the pump pulse energy and waveguide geometry, high-efficiency and broadband dispersive waves can be achieved on this platform.
News Item
Optics
Jeffrey Moses, Shu-Wei Huang
Summary: Coherent multi-octave mid-infrared waveforms can be generated and manipulated using cascaded intrapulse difference-frequency generation, providing absolute phase control and expanding the techniques available for arbitrary light-wave control.
Article
Optics
Geoffroy Granger, Myriam Bailly, Hugo Delahaye, Cristian Jimenez, Idris Tiliouine, Yann Leventoux, Jean-Christophe Orlianges, Vincent Couderc, Bruno Gerard, Rezki Becheker, Said Idlahcen, Thomas Godin, Ammar Hideur, Arnaud Grisard, Eric Lallier, Sebastien Fevrier
Summary: The mid-infrared spectral region offers new possibilities for molecular spectroscopy with high resolution. This study introduces orientation-patterned gallium arsenide waveguides as a versatile platform for mid-infrared supercontinuum generation and demonstrates its potential for high-brightness, high-resolution mid-infrared laser sources.
LIGHT-SCIENCE & APPLICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Ma Ziyang, Li Li, Ni Xiaowu
Summary: This paper theoretically investigates the supercontinuum generation using a novel photonic-crystal pillar waveguide (PCPW) spanning from near-infrared (NIR) to mid-infrared. By optimizing the PCPW design and dispersion properties, the study achieves ultra-broadband spectral broadening from 1 to 10 micrometers under relatively lower peak power pump pulses. The proposed PCPW offers an efficient waveguide structure for generating ultra-broadband supercontinuum with shorter wavelength laser sources.
OPTICAL AND QUANTUM ELECTRONICS
(2021)
Article
Physics, Multidisciplinary
Di Xia, Yufei Huang, Bin Zhang, Zelin Yang, Pingyang Zeng, Haiyan Shang, Huanjie Cheng, Linghao Liu, Mingjie Zhang, Ying Zhu, Zhaohui Li
Summary: This study numerically investigates on-chip ultrabroadband MIR SCG in a high numerical aperture chalcogenide waveguide. By optimizing the nonlinear coefficients and dispersion profile of the ChG waveguide with a Ge-As-Se-Te core and Ge-Se upper and lower cladding, broadband SCG ranging from 2 to 13 μm is achieved. A fabrication scheme is proposed for precise manipulation of dispersion design in such sources suitable for compact, chip-integrated molecular spectroscopy applications.
FRONTIERS IN PHYSICS
(2021)
Article
Optics
Luqi Zhang, Jinhui Yuan, Yujun Cheng, Chao Mei, Jintao Lai, Xian Zhou, Qiang Wu, Binbin Yan, Kuiru Wang, Chongxiu Yu, Xinzhu Sang
Summary: A polarization-insensitive reverse-ridge AlGaAs waveguide was designed for supercontinuum generation in this study. Simulation results showed that under specific conditions, the supercontinuum generated through this waveguide structure could overlap well.
OPTICS COMMUNICATIONS
(2022)
Article
Engineering, Electrical & Electronic
M. R. Karim, Nayem Al Kayed, Nusrat Jahan, M. Shah Alam, B. M. A. Rahman
Summary: A new type of suspended core tapered waveguide is proposed for supercontinuum generation in the midinfrared. By optimizing the waveguide dimensions and using different tapering methods, better spectral coverage and spectral flatness can be achieved.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Guorui Chen, Aaron L. Sharpe, Eli J. Fox, Shaoxin Wang, Bosai Lyu, Lili Jiang, Hongyuan Li, Kenji Watanabe, Takashi Taniguchi, Michael F. Crommie, Marc A. Kastner, Zhiwen Shi, David Goldhaber-Gordon, Yuanbo Zhang, Feng Wang
Summary: The study reports the experimental observation of ferromagnetism at noninteger filling of a flat Chern band in a ABC-TLG/hBN moire superlattice. The state exhibits prominent ferromagnetic hysteresis behavior with large anomalous Hall resistivity in a broad region of densities centered in the valence miniband at n = -2.3n(0). The magnitude and sign of the anomalous Hall signal can be modulated by tuning the carrier density and displacement field. The ferromagnetism is highly anisotropic and likely purely orbital in character.
Article
Optics
Atsushi Ishizawa, Kota Kawashima, Rai Kou, Xuejun Xu, Tai Tsuchizawa, Takuma Aihara, Koki Yoshida, Tadashi Nishikawa, Kenichi Hitachi, Guangwei Cong, Noritsugu Yamamoto, Koji Yamada, Katsuya Oguri
Summary: We achieved the simultaneous generation of a wide spectrum of supercontinuum and third-harmonic light using a dispersion-controlled silicon-nitride waveguide. By fabricating special waveguides and utilizing their properties, we were able to measure accurate carrier-envelope-offset signals and demonstrate the method's application at telecommunication wavelengths.
Article
Physics, Multidisciplinary
Yan Meng, Xiaoxiao Wu, Yaxi Shen, Dong Liu, Zixian Liang, Xiang Zhang, Jensen Li
Summary: This article introduces a new device based on non-Hermitian topological systems, which combines the advantages of topological robustness and non-Hermiticity to achieve continuous and quantitative control of energy distribution ratio of waves. The device can be used as a sensitive beam splitter or a coupler switch, with potential applications in elastic circuits or networks.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2022)
Article
Materials Science, Multidisciplinary
Nicholas Dale, Ryo Mori, M. Iqbal Bakti Utama, Jonathan D. Denlinger, Conrad Stansbury, Claudia G. Fatuzzo, Sihan Zhao, Kyunghoon Lee, Takashi Taniguchi, Kenji Watanabe, Chris Jozwiak, Aaron Bostwick, Eli Rotenberg, Roland J. Koch, Feng Wang, Alessandra Lanzara
Summary: This study reports an effective method to access electron-hole asymmetry in 2D materials by directly measuring the quasiparticle self-energy in graphene/Boron Nitride field-effect devices. The results suggest that electronic correlations intrinsically drive the electron-hole asymmetry in graphene.
NPJ QUANTUM MATERIALS
(2022)
Article
Multidisciplinary Sciences
Jixiang Yang, Guorui Chen, Tianyi Han, Qihang Zhang, Ya-Hui Zhang, Lili Jiang, Bosai Lyu, Hongyuan Li, Kenji Watanabe, Takashi Taniguchi, Zhiwen Shi, Todadri Senthil, Yuanbo Zhang, Feng Wang, Long Ju
Summary: We report spectroscopy measurements of dual-gated TLG/hBN using Fourier transform infrared photocurrent spectroscopy and observe optical transitions and bandgap opening, providing insights into the electron correlation in TLG/hBN.
Review
Nanoscience & Nanotechnology
Emma C. Regan, Danqing Wang, Eunice Y. Paik, Yongxin Zeng, Long Zhang, Jihang Zhu, Allan H. MacDonald, Hui Deng, Feng Wang
Summary: This Review discusses two approaches for realizing emergent excitonic physics in two-dimensional semiconductor heterostructures: the introduction of a moire superlattice and the formation of an optical cavity.
NATURE REVIEWS MATERIALS
(2022)
Article
Chemistry, Physical
Cong Su, Fang Zhang, Salman Kahn, Brian Shevitski, Jingwei Jiang, Chunhui Dai, Alex Ungar, Ji-Hoon Park, Kenji Watanabe, Takashi Taniguchi, Jing Kong, Zikang Tang, Wenqing Zhang, Feng Wang, Michael Crommie, Steven G. Louie, Shaul Aloni, Alex Zettl
Summary: Colour centre emission from hexagonal boron nitride (hBN) shows promise for quantum technologies, but activation and tuning are challenging. In this study, the authors demonstrate the tuning of emission brightness by adjusting the twist angle and modulation of brightness with external voltage at the twisted interface of hBN flakes.
Article
Chemistry, Physical
Tiancong Zhu, Wei Ruan, Yan-Qi Wang, Hsin-Zon Tsai, Shuopei Wang, Canxun Zhang, Tianye Wang, Franklin Liou, Kenji Watanabe, Takashi Taniguchi, Jeffrey B. Neaton, Alexander Weber-Bargioni, Alex Zettl, Z. Q. Qiu, Guangyu Zhang, Feng Wang, Joel E. Moore, Michael F. Crommie
Summary: The authors used scanning tunnelling microscopy and spectroscopy to study the mirror twin boundaries in single-layer 1H-MoSe2 devices. By adjusting the electron density, they successfully visualized the electronic structure of the mirror twin boundaries and confirmed the presence of density wave excitations and spin-charge separation effects, in agreement with the predictions of the Tomonaga-Luttinger liquid theory.
Article
Physics, Multidisciplinary
Zuocheng Zhang, Emma C. Regan, Danqing Wang, Wenyu Zhao, Shaoxin Wang, Mohammed Sayyad, Kentaro Yumigeta, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Michael Crommie, Alex Zettl, Michael P. Zaletel, Feng Wang
Summary: This study reports the observation of a correlated interlayer exciton insulator in a double-layer heterostructure composed of a WSe2 monolayer and a WS2/WSe2 moire bilayer. A new interlayer exciton insulator emerges when electrons are added to the WS2/WSe2 moire bilayer and an equal number of holes are injected into the WSe2 monolayer.
Article
Multidisciplinary Sciences
Mit H. Naik, Emma C. Regan, Zuocheng Zhang, Yang-Hao Chan, Zhenglu Li, Danqing Wang, Yoseob Yoon, Chin Shen Ong, Wenyu Zhao, Sihan Zhao, M. Iqbal Bakti Utama, Beini Gao, Xin Wei, Mohammed Sayyad, Kentaro Yumigeta, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Felipe H. da Jornada, Feng Wang, Steven G. Louie
Summary: The nature of exciton resonances in WSe2/WS2 moire superlattices is identified using large-scale first-principles GW and Bethe-Salpeter calculations, along with micro-reflection spectroscopy. A rich set of moire excitons, including modulated Wannier excitons and previously unidentified intralayer charge-transfer excitons, is discovered, indicating highly non-trivial exciton states that can emerge in transition metal dichalcogenide moire superlattices.
Article
Physics, Multidisciplinary
Yi Chen, Wen-Yu He, Wei Ruan, Jinwoong Hwang, Shujie Tang, Ryan L. Lee, Meng Wu, Tiancong Zhu, Canxun Zhang, Hyejin Ryu, Feng Wang, Steven G. Louie, Zhi-Xun Shen, Sung-Kwan Mo, Patrick A. Lee, Michael F. Crommie
Summary: Researchers deposited magnetic atoms onto a single-layer 1T-TaSe2 and observed the emergence of new resonance peaks. The experimental results are consistent with theoretical simulations, indicating that these peaks are caused by Kondo resonance induced by spinons and spin-charge binding effects.
Article
Chemistry, Multidisciplinary
Yoseob Yoon, Zuocheng Zhang, Ruishi Qi, Andrew Y. Joe, Renee Sailus, Kenji Watanabe, Takashi Taniguchi, Sefaattin Tongay, Feng Wang
Summary: Ultrafast charge transfer processes provide a simple way to create interlayer excitons in directly contacted transition metal dichalcogenide (TMD) layers. More sophisticated TMD/hBN/TMD heterostructures enable control over interlayer exciton properties and the emergence of novel exciton phenomena. The study investigates the charge transfer dynamics in a heterostructure composed of MoSe2 and WSe2 monolayers with a 1 nm thick hBN spacer, observing slower hole transfer compared to TMD layers without a spacer, as well as strong competition between interlayer charge transfer and intralayer exciton-exciton annihilation processes at high excitation densities.
Article
Nanoscience & Nanotechnology
Aditya Sood, Jonah B. Haber, Johan Carlstrom, Elizabeth A. Peterson, Elyse Barre, Johnathan D. Georgaras, Alexander H. M. Reid, Xiaozhe Shen, Marc E. Zajac, Emma C. Regan, Jie Yang, Takashi Taniguchi, Kenji Watanabe, Feng Wang, Xijie Wang, Jeffrey B. Neaton, Tony F. Heinz, Aaron M. Lindenberg, Felipe H. da Jornada, Archana Raja
Summary: In this study, lattice dynamics in photoexcited WSe2/WS2 heterostructures were directly visualized using femtosecond electron diffraction. It was found that both WSe2 and WS2 were heated simultaneously on a picosecond timescale, which cannot be explained by phonon transport across the interface. First-principles calculations revealed a fast channel involving layer-hybridized electronic states, enabling phonon-assisted interlayer transfer of photoexcited electrons. Phonons were emitted in both layers on the femtosecond timescale via this channel, consistent with the simultaneous lattice heating observed experimentally. Strong electron-phonon coupling via layer-hybridized electronic states was identified as a novel route for controlling energy transport across atomic junctions.
NATURE NANOTECHNOLOGY
(2023)
Article
Optics
Rai Kou, Atsushi Ishizawa, Koki Yoshida, Norisugu Yamamoto, Xuejun Xu, Yugo Kikkawa, Kota Kawashima, Takuma Ihara, Tai Suchizawa, Guangwei Cong, Kenichi Hitachi, Tadashi Nishikawa, Katsuya Oguri, Koji Yamada
Summary: We propose a method to enhance supercontinuum light generation in a precisely dispersion-engineered deuterated SiN waveguide through multimode excitation. By applying spatial position offsets to excite fundamental and higher-order modes, we achieved bandwidth broadening with flatness. The SNR improvement of up to 18 dB at a wavelength of 0.6 μm was attributed to the presence of dispersive waves due to the excitation of TE10 and TE01 modes.
Article
Chemistry, Multidisciplinary
Chunhui Dai, Yoonsoo Rho, Khanh Pham, Brady McCormick, Brian W. Blankenship, Wenyu Zhao, Zuocheng Zhang, Michael F. Crommie, Feng Wang, Costas P. Grigoropoulos, Alex Zettl
Summary: The low mass density and high mechanical strength of graphene make it an attractive material for suspended-membrane energy transducers. In this study, kirigami engineering was used to modify suspended pure-graphene membranes, resulting in a reduction in resonance frequency, an increase in displacement amplitude, and broadening of the transducer's effective bandwidth. This research presents a promising approach for miniaturized wide-band energy transducers with improved operational parameters and efficiency.
