Article
Optics
Mikhail Roiz, Jui-Yu Lai, Juho Karhu, Markku Vainio
Summary: Efficient generation of mid-infrared frequency combs is demonstrated based on continuous-wave-seeded femtosecond optical parametric generation in nonlinear waveguides. The conversion efficiency of the near-infrared pump to signal and idler light is high, with exceptionally low relative intensity noise in the mid-infrared comb. Additionally, the mid-infrared bandwidth can be increased by driving the process with a broadband pump obtained via supercontinuum generation.
Article
Optics
Yuxin Ma, Biqiang Jiang, Yasong Guo, Pengwei Zhang, Tonglei Cheng, Xuetao Gan, Jianlin Zhao
Summary: We present an all-fiber scheme for second harmonic generation (SHG) by incorporating gallium selenide (GaSe) nanosheets into a suspended-core fiber (SCF). The phase-matching modes and optimal SCF length are determined through mode analysis and theoretical calculations. The SHG signal, observed under milliwatt-level pump light, exhibits a quadratic growth with increasing pump power due to the long-distance interaction between the pumped fundamental mode and GaSe nanosheets. Additionally, the SHG process is achieved over a broad wavelength range by varying the pump wavelength.
Article
Optics
Gia Quyet Ngo, Emad Najafidehaghani, Ziyang Gan, Sara Khazaee, Malte Per Siems, Antony George, Erik P. Schartner, Stefan Nolte, Heike Ebendorff-Heidepriem, Thomas Pertsch, Alessandro Tuniz, Markus A. Schmidt, Ulf Peschel, Andrey Turchanin, Falk Eilenberger
Summary: This study demonstrates a method to achieve second-harmonic generation in functionalized optical fibers by directly growing highly nonlinear MoS2 monolayers on the fiber's core. The approach is scalable and can be generalized to other materials and waveguide systems.
Article
Optics
Rezki Becheker, Myriam Bailly, Sai Idlahcen, Thomas Godin, Bruno Gerard, Hugo Delahaye, Geoffroy Granger, Sebastien Fevrier, Arnaud Grisard, Eric Lallier, Ammar Hideur
Summary: We report on the mid-infrared optical parametric generation experiment in the 4-5 μm and 9-12 μm bands using custom-designed orientation-patterned gallium arsenide (OP-GaAs) rib waveguides. The pump source is driven by an ultrafast femtosecond fiber laser system seeded by a mode-locked fluoride fiber laser, and it can be tuned between 2.8 and 3.2 μm using a soliton self-frequency shifting stage. The OP-GaAs crystals with single TE and TM modes feature quasi-phase-matched grating periods of 85 and 90 μm and different transverse sizes, allowing for wide spectral tunability.
Article
Optics
Yang Xu, Sirui Tang, Nicholas Black, Robert w. Boyd
Summary: This study proposes a spatial domain extension of orthogonal optical coding scheme for image information transmission. By utilizing the phase conjugation property of stimulated parametric down-conversion, the encoded image is transferred and restored using encoding and corrective phase masks.
Article
Physics, Multidisciplinary
Zhen-Yang Peng, Ying-Dan Wang
Summary: We investigated the process of polariton conversion in a 3-mode nonlinear optomechanical system and found a higher conversion rate compared to the standard 2-mode system. By adiabatically eliminating the cavity in the large detuned case, we achieved a parametric down-conversion interaction between two phononic polariton modes. The nonlinear interaction can be enhanced by tuning the cavity detuning, which was confirmed through analytical treatment and numerical simulation. This system holds potential applications in nonlinear phononics.
COMMUNICATIONS IN THEORETICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Lisa Arndt, Fabian Hassler
Summary: This letter discusses the phenomenon of discrete time-translation symmetry breaking in periodically driven systems and proposes the use of quantum vacuum fluctuations to induce period multiplication. The authors demonstrate, using a circuit QED setup, that the system exhibits a nonequilibrium phase transition under weak dissipation or strong driving conditions.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Applied
N. Rubiano da Silva, A. G. de Oliveira, M. F. Z. Arruda, R. Medeiros de Araujo, W. C. Soares, S. P. Walborn, R. M. Gomes, P. H. Souto Ribeiro
Summary: The experimental results are in good agreement with theory, showing diverse polarization transverse distributions for different combinations of pump and seed vector vortex beams, which may find applications in both classical and quantum optics.
PHYSICAL REVIEW APPLIED
(2021)
Article
Optics
Yue Li, Jie Wu, Hao Zhou, Guoliang Deng, Shouhuan Zhou
Summary: We successfully fabricated depressed cladding waveguides in sapphire crystal using a femtosecond laser. Experimental studies and comparisons of supercontinuum generation (SCG) were conducted in waveguides and bulk sapphire. The results show that the SCG efficiency improves and the threshold decreases in the waveguide compared to bulk sapphire, indicating the great potential of femtosecond laser fabricated waveguides for SCG.
OPTICS AND LASER TECHNOLOGY
(2023)
Article
Optics
Mikhail Roiz, Markku Vainio
Summary: This study proposes and demonstrates a versatile method for near- and mid-infrared optical frequency comb generation using multi-seeded femtosecond optical parametric generation, showing flexibility and adjustability.
Review
Quantum Science & Technology
Chao Zhang, Yun-Feng Huang, Bi-Heng Liu, Chuan-Feng Li, Guang-Can Guo
Summary: Entangled photon sources, generated through the SPDC process, are essential for photonic quantum information processing. This review article examines different types of SPDC sources suitable for multiphoton experiments, comparing their performance in terms of indistinguishability, collection efficiency, and brightness. Recent advancements in multiplexed heralded single-photon sources are also discussed, which help mitigate the probabilistic nature of the SPDC process.
ADVANCED QUANTUM TECHNOLOGIES
(2021)
Article
Optics
Jiajin Zheng, Jun Jiang, Huanquan Chen, Ruilin Zheng, Xiao Shen, Kehan Yu, Wei Wei
Summary: Nonlinear optical glasses, specifically tellurite glasses, have shown great potential for generating supercontinuum spectra in optical fiber systems. High-refractive-index tellurite glasses exhibit strong nonlinear absorption and refractive index values, making them excellent candidates for broadband mid-IR supercontinuum generation.
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Optics
Honggeng Wang, Huangcheng Shangguan, Qiying Song, Yi Cai, Qinggang Lin, Xiaowei Lu, Zhanxin Wang, Shuiqin Zheng, Shixiang Xu
Summary: Investigation on the generation and evolution of different pulsed terahertz singular beams in long gas-plasma filaments induced by a shaped two-color laser field revealed three different types of THz singular beams, showcasing their generation mechanism.
Article
Optics
Ying-Qiu He, Dong Ding, Feng-Li Yan, Ting Gao
Summary: This article explores the differences between higher-order parametric down-conversion (PDC) photon states and states involving independent photon pairs, with a focus on third-order PDC photons. By utilizing symmetry detectors and cascading operations, the generation of third-order PDC photons from twin-beam six-photon symmetric states is achieved, showcasing their application in exploring six-mode-photon entangled states with linear optics.
JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS
(2021)
Article
Optics
Igor Kinyaevskiy, Valery Kovalev, Pavel Danilov, Nikita Smirnov, Sergey Kudryashov, Andrey Koribut, Andrey Ionin
Summary: The spectral broadening of a 0.3 ps 515 nm laser pulse in highly Raman-active BaWO4 crystal and fused silica shows significantly different behaviors with respect to incident pulse energy. The data obtained provide evidence of stimulated Raman scattering slowing down spectral broadening induced by self-phase modulation, and also suggest that the mechanism of Kerr nonlinearity in BaWO4 is of orientational nature. The nonlinear refractive coefficient and decay time were estimated to be n(2) approximately 6.4×10(-15) cm(2)/W and tau(NL) approximately 0.35 ps from experiments with BaWO4.
Article
Optics
Matthias Liebtrau, Murat Sivis, Armin Feist, Hugo Lourenco-Martins, Nicolas Pazos-Perez, Ramon A. Alvarez-Puebla, F. Javier Garcia de Abajo, Albert Polman, Claus Ropers
Summary: The study focuses on the nanoscale features of spontaneous and stimulated electron-photon interactions mediated by localized surface plasmon resonances, using various optical techniques to show different coupling mechanisms and the influence of incident electron velocity on interaction strength. The findings highlight the importance of understanding these interactions for research on coherent optical phenomena at the nanoscale.
LIGHT-SCIENCE & APPLICATIONS
(2021)
Article
Multidisciplinary Sciences
Ofer Kfir, Valerio Di Giulio, F. Javier Garcia de Abajo, Claus Ropers
Summary: This theoretical study investigates the quantum-coherence properties of cathodoluminescence emission generated by a temporally modulated electron beam, revealing the presence of phase correlations between the emitted CL field and the electron-modulating laser. The coherence of the CL field extends to harmonics of the laser frequency, suggesting the potential for ultra-precise manipulation and probing of nanoscale quantum systems through the optical coherence transferred by electron beams focused to below 1 A.
Article
Physics, Applied
G. Storeck, K. Rossnagel, C. Ropers
Summary: The researchers investigated the optically driven phase transition between two charge-density wave (CDW) states at the surface of tantalum disulfide (1T-TaS2) using an improved ultrafast low-energy electron diffraction setup. The experimental results showed that there was a substantial IC-peak broadening for very short time scales followed by a prolonged spot narrowing.
APPLIED PHYSICS LETTERS
(2021)
Article
Materials Science, Multidisciplinary
Tyler R. Harvey, Nara Rubiano da Silva, John H. Gaida, Marcel Moeller, Armin Feist, Sascha Schaefer, Claus Ropers
Summary: This article reviews the physical interactions that produce ultrafast magnetic contrast with electrons and highlights the recent emergence of ultrafast Lorentz transmission electron microscopy. It demonstrates that ultrafast electron imaging will be a vital tool in solving pressing problems in magnetism and magnetic materials.
Article
Chemistry, Physical
N. Bach, A. Feist, M. Moeller, C. Ropers, S. Schaefer
Summary: Optically excited nanostructures serve as a versatile platform for generating confined nanophononic fields with potential (non-)linear couplings. In this study, a semiconductor membrane patterned with a platinum stripe was utilized to generate high-frequency strain waves, and the ultrafast structural dynamics were monitored using ultrafast convergent beam electron diffraction. The experimental results were reproduced by numerical simulations, revealing the spatiotemporal evolution of lattice dynamics dominated by local rotations.
STRUCTURAL DYNAMICS-US
(2022)
Article
Multidisciplinary Sciences
Armin Feist, Guanhao Huang, Germaine Arend, Yujia Yang, Jan-Wilke Henke, Arslan Sajid Raja, F. Jasmin Kappert, Rui Ning Wang, Hugo Lourenco-Martins, Zheru Qiu, Junqiu Liu, Ofer Kfir, Tobias J. Kippenberg, Claus Ropers
Summary: In this work, we show the preparation of electron-photon pair states by exploiting the phase-matched interaction between free electrons and the optical microresonator on a photonics chip. This breakthrough provides a foundation for the future development of free-electron quantum optics.
Article
Chemistry, Physical
Hannes Boeckmann, Jan Gerrit Horstmann, Abdus Samad Razzaq, Stefan Wippermann, Claus Ropers
Summary: Exploiting vibrational excitation for dynamic control of material properties has wide-ranging technological potential. This study demonstrates mode-selective control over the metal-to-insulator phase transition in indium wires, enabling navigation of collective atomic motion within the potential energy surface. Exciton-phonon interactions allow for dynamic control of materials functionality.
STRUCTURAL DYNAMICS-US
(2022)
Article
Optics
Rudolf Haindl, Kerim Koester, John H. Gaida, Maximilian Franz, Armin Feist, Claus Ropers
Summary: We demonstrate photoassisted cold field emission (PFE) from a tungsten tip induced by tunable-wavelength low-power femtosecond laser excitation. The emission current from the apex of the (310)-oriented single-crystalline emitter is shown to linearly depend on the incident laser power, while the effective work function is reduced by the respective photon energy. Our results promote the implementation of the linear regime in laser-triggered cold field emission for ultrafast transmission electron microscopy.
APPLIED PHYSICS B-LASERS AND OPTICS
(2023)
Article
Physics, Multidisciplinary
F. Javier Garcia de Abajo, Claus Ropers
Summary: The modulation of free electrons with light has been found to be effective in producing attosecond electron wave packets. However, existing research mainly focuses on manipulating the longitudinal wave function component, with limited attention given to the transverse degrees of freedom for temporal shaping. In this study, by utilizing parallel light-electron interactions in separate zones, we demonstrate the simultaneous spatial and temporal compression of a convergent electron wave function, resulting in the formation of sub-angstrom focal spots of attosecond duration. This approach opens up new possibilities for exploring ultrafast atomic-scale phenomena, particularly in attosecond scanning transmission electron microscopy.
PHYSICAL REVIEW LETTERS
(2023)
Article
Multidisciplinary Sciences
John H. Gaida, Hugo Lourenco-Martins, Sergey V. Yalunin, Armin Feist, Murat Sivis, Thorsten Hohage, F. Javier Garcia de Abajo, Claus Ropers
Summary: The paper introduces Lorentz-PINEM for full-field, non-invasive imaging of complex optical near fields at high spatial resolution. The authors use energy-filtered defocus phase-contrast imaging and iterative phase retrieval to reconstruct the phase distribution of interfering surface-bound modes on a plasmonic nanotip. Their approach is applicable for retrieving the spatially varying phase of nanoscale fields and topological modes.
NATURE COMMUNICATIONS
(2023)
Article
Physics, Multidisciplinary
Marcel Moeller, John H. Gaida, Claus Ropers
Summary: The effect of grain size in polycrystalline permalloy films on the pinning and gyration orbits of vortex cores inside magnetic nanoislands is studied. Static pinning is found to be governed by grain boundaries, while samples with larger grains show characteristic changes to the vortex gyration.
PHYSICAL REVIEW RESEARCH
(2022)
Proceedings Paper
Engineering, Electrical & Electronic
Tobias Heinrich, Marco Taucer, Ofer Kfir, P. B. Corkum, Andre Staudte, Claus Ropers, Murat Sivis
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Armin Feist, Sergey Yalunin, Sascha Schaefer, Claus Ropers
2021 CONFERENCE ON LASERS AND ELECTRO-OPTICS EUROPE & EUROPEAN QUANTUM ELECTRONICS CONFERENCE (CLEO/EUROPE-EQEC)
(2021)
Proceedings Paper
Engineering, Electrical & Electronic
Rudolf Haindl, Kerim Koester, Armin Feist, Claus Ropers
Summary: In this study, the wavelength-dependent linear photoemission from W(310)-nanotips operated in a Schottky-type emitter assembly was investigated. Fowler-Nordheim plots of the electron current were recorded for both static field emission and photoemission with varying laser wavelengths. One-photon photoassisted field emission was observed for all wavelengths, as demonstrated by the perfect agreement of the experimental data with Fowler-Nordheim tunneling theory.
2021 34TH INTERNATIONAL VACUUM NANOELECTRONICS CONFERENCE (IVNC)
(2021)
Article
Physics, Multidisciplinary
Sergey Yalunin, Armin Feist, Claus Ropers
Summary: The study introduces an approach for generating background-free attosecond electron pulse trains by sequential inelastic electron-light scattering, effectively suppressing unwanted background density in electron compression using quantum interference, which will greatly enhance applications of coherent electron-light scattering techniques.
PHYSICAL REVIEW RESEARCH
(2021)
