bluuebunny/crossref_metadata_2025 huggingface dataset:
Real-time Voice Sensing and Speech Recognition System Based on One-way Ring Sagnac Fiber Interferometer
Authors: Hu Yuhan , Song Qiuheng , Jia Kun , Lai Xin , Peng Hekuo , Chen Yongchao , Xiao Qian , Fudan Bo Jia
Published: September 2022

We propose a novel one-way ring optical fiber Sagnac system for voice sensing. The system can realize real-time speech-to-text speech recognition using an open-source neural network model.
Quantum-limited absorption estimation with ring resonators
Authors: Belsley Alexandre , Allen Euan J. , Datta Animesh , Matthews Jonathan C. F.
Published: September 2022

Coherent-state probes in appropriately designed all-pass ring resonators outperform any quantum probe single-pass absorption estimation strategy, including those using Fock or bright squeezed states.
Exchange-Free Polarimetry of a Polarising Object
Authors: Hance Jonte R. , Rarity John
Published: September 2022

We extend exchange-free imaging to polarimetry of a polarising object. This allows imaging of these samples with far less absorbed energy - a key concern when imaging with high-frequency radiation.
A Monolithic Lab-on-a-Chip for Real Time Liquid Spectroscopy
Authors: Hinkov Borislav , Pilat Florian , Lux Laurin , Souza Patricia L. , David Mauro , Schwaighofer Andreas , Baumgartner Bettina , Ristanić Daniela , Schwarz Benedikt , Detz Hermann , Andrews Aaron M. , Lendl Bernhard , Strasser Gottfried
Published: September 2022

We present a monolithic mid-infrared lab-on-a-chip for sensitive and selective real-time liquid spectroscopy. Beyond state-of-the-art operation of our fingertip-sized devices is demonstrated by in-situ reaction-monitoring of thermally-induced protein-conformational changes and by dynamical residual-water analysis in solvents.
Fiber Ring Resonator based on Adhesive Bond for Ultrasonic Sensing
Authors: Kim Jee Myung , Peters Kara
Published: September 2022

We demonstrate sensing based on an acoustic fiber ring resonator using optical fiber adhesive coupling for temperature sensing based on in acoustic path length and water level based on acoustic loss per unit length.
Photopolymer Ring-Resonator Based Temperature Sensor Directly 3D Printed on a Dual-Core Optical Fiber Tip
Authors: Gill Parvinder Kaur , Marom Dan M.
Published: September 2022

We 3D-print a nanofin-supported waveguide bridging two cores at the fiber tip and further coupled to a printed ring resonator. The resonance wavelength shift is probed from the fiber’s distal end, shifting by 47 pm/°K.
Tapered Tip Optical Fiber Refractometer with Dramatically Enhanced Sensitivity
Authors: Lu Chunyu , Nikbakht Hamed , Erdolu Mert Yusuf , van Someren Bob , Akca B. Imran
Published: September 2022

Based on a simply-built setup, we demonstrated an inexpensive refractive index sensor. An unprecedented sensitivity value was obtained, which is the highest value reported so far among intensity modulated fiber refractometers.
Optimization of the output polarization state in multi-pass cell enhanced Faraday rotation spectrometers
Authors: Shashaty Kasey , Patrick Link , Wysocki Gerard
Published: September 2022

Multi-pass cell-enhanced Faraday rotation spectroscopy for paramagnetic gas species is affected by elliptical polarization introduced by interactions within the cell mirrors. We demonstrate a reduction in unwanted ellipticity using a quarter wave plate and quantify the improvement in SNR.
Multiple quantum well discrete-mode laser based dual frequency comb operating at 2 μm
Authors: Russell Eoin , Corbett Brian , Gunning Fatima Cristina Garcia
Published: September 2022

We demonstrate a dual frequency comb based on gain-switched multiple quantum well discrete-mode laser sources and mutual optical injection locking. The DFC generated spanned approximately 100 GHz around 2.002 μm with 2 GHz frequency spacing.
Direct Visualization of Polaron Formation in the Thermoelectric SnSe
Authors: de Cotret Laurent P. René , Otto Martin R. , Pöhls Jan-Hendrik , Luo Zhongzhen , Kanatzidis Mercouri G. , Siwick Bradley J.
Published: September 2022

Using ultrafast electron scattering we directly observe the bimodal and anisotropic lattice distortions that drive carrier localization in SnSe. Large (18.7 Å), quasi-1D polarons form in 300 fs and smaller (4.2 Å) 3D polarons form in 4 ps.
Momentum-resolved non-radiative energy flow in photoexcited black phosphorus
Authors: Seiler Hélène , Zahn Daniela , Zacharias Marios , Hildebrandt Patrick-Nigel , Vasileiadis Thomas , Windsor Yoav William , Qi Yingpeng , Carbogno Christian , Draxl Claudia , Ernstorfer Ralph , Caruso Fabio
Published: September 2022

We perform femtosecond electron diffuse scattering measurements on black phosphorus. We reproduce the non-equilibrium structural dynamics using ultrafast dynamics simulations based on the time-dependent Boltzmann formalism and calculations of the all-phonon structure factor.
Sub-Cycle Phonon Dynamics Induced by Ultrafast Electron-Phonon Relaxations in 2D Carbide Ti3C2Tx (MXene)
Authors: Neb S. , Shin D. , Schumacher Z. , Niedermayr A. , Kuznetsov D. A. , Müller C. R. , Fedorov A. , Sato S. A. , Rubio A. , Gallmann L. , Keller U.
Published: September 2022

Attosecond transient absorption spectroscopy in two-dimensional functionalized transition metal carbide unveils ultrafast element, site, and carrier-specific electron-phonon relaxations on the few-femtosecond timescale and provides new insights towards engineering of electronic heat dissipation at atomic scale.
Capturing ultrafast synergistic spin transition in a multifunctional hybrid spin crossover system by ultrafast optical spectroscopy and electron diffraction
Authors: Jiang Yifeng , Hayes Stuart , Bittmann Simon , Sarracini Antoine , Liu Lai Chung , Müller-Werkmeister Henrike M. , Wentzell Jordan S. , Takahashi Kazuyuki , Miyawaki Atsuhiro , Hada Masaki , Nakano Shinnosuke , Koshihara Shin-ya , Ishikawa Tadahiko , Dwayne Miller R. J.
Published: September 2022

Multifunctional spin crossover (SCO) complexes provide control over electronic properties of anions. Here, we study a prototypical complex to understand ultrafast reaction pathways and transitional structures and open a way for fast responsive multi-level photoswitches.
Ultrafast transient absorption spectroscopy of salicylideneaniline under jet-cooled and Ar cluster conditions
Authors: Silfies Myles C. , Mehmood Arshad , Kowzan Grzegorz , Levine Benjamin G. , Allison Thomas K.
Published: September 2022

We study ultrafast excited-state proton transfer and subsequent internal conversion in salicylideneaniline using broadband cavity-enhanced transient absorption spectroscopy. By comparing gas-phase optical spectra to solution-phase spectra and ab initio theory, competing relaxation pathways are elucidated.
Imaging rehybridization dynamics into pericyclic minimum of an electrocyclic reaction in real-time
Authors: Liu Yusong , Sanchez David M. , Ware Mathew R. , Champenois Elio G. , Yang Jie , Nunes J. Pedro F. , Attar Andrew , Centurion Martin , Forbes Ruaridh , Gühr Markus , Hegazy Kareem , Hoffmann Matthias C. , Ji Fuhao , Lin Ming-Fu , Luo Duan , Mayer Dennis , Saha Sajib K. , Shen Xiaozhe , Weathersby Stephen , Wang Xijie , Martínez Todd J. , Wolf Thomas J. A.
Published: September 2022

We observed structural evolution into the excited state pericyclic minimum during photochemical ring-opening of α-terpinene by ultrafast electron diffraction and ab-initio multiple spawning wavepacket simulation.
Conformer-specific photochemistry imaged in real space and time
Authors: Champenois E. G. , Sanchez D. M. , Yang J. , Figueira Nunes J. P. , Attar A. , Centurion M. , Forbes R. , Gühr M. , Hegazy K. , Ji F. , Liu Y. , Lin M.-F. , Luo D. , Moore B. , Saha S. K. , Shen X. , Ware M. R. , Wang X. J. , Martínez T. J. , Wolf T. J. A.
Published: September 2022

We imaged the conformer-specificity of an electrocyclic ring-opening reaction as predicted by the Woodward-Hoffmann rules in real space and time employing a combination of ultrafast electron diffraction and excited state dynamics simulations.
Unveiling Vibronic Coupling within the Q-bands of a Free-base Porphyrin
Authors: Petropoulos Vasilis , Russo Mattia , Rukin Pavel , Quintela Frank , Moretti Luca , Moore Ana , Moore Thomas , Gust Devens , Prezzi Deborah , Scholes Gregory , Molinari Elisa , Troiani Filippo , Cerullo Giulio , Rozzi Carlo , Maiuri Margherita
Published: September 2022

Multidimensional spectroscopies unveil the presence of vibronic coupling within the Q-states in a free-base porphyrin. High-frequency coupling and tuning modes drive the ultrafast internal conversion and track the excited state structural evolution.
Watching Molecules in Action: Cobalamins as a Case Study
Authors: Sension Roseanne J. , Chung Taewon , Deb Aniruddha , Lamb Ryan M. , McClain Taylor P. , Penner-Hahn James E.
Published: September 2022

Femtosecond X-ray spectroscopy is used to characterize the internal conversion and coherent excited state evolution of typical cobalamins. Cobalt Kα and Kβ emission probes electronic dynamics while Cobalt K-edge XANES probes structural evolution.
2D Impulsively Stimulated Resonant Raman Spectroscopy of Molecular Excited States
Authors: Fumero G. , Schnedermann C. , Batignani G. , Wende T. , Liebel M. , Bassolino G. , Ferrante C. , Mukamel S. , Kukura P. , Scopigno T.
Published: September 2022

We combine the advantages of vibrational and electronic multidimensional spectroscopies in a 2D impulsively stimulated Raman scheme to selectively study vibronic properties during excited-state dynamics in molecules, an open problem in ultrafast science which is not accessible by lower order techniques.
Ultrafast N K-Edge Spectroscopy of Strong Field Ionization and Fragmentation Dynamics of Molecular Nitrogen
Authors: Kleine Carlo , Winghart Marc-Oliver , Zhang Zhuang-Yan , Ekimova Maria , Eckert Sebastian , Vrakking Marc J. J. , Nibbering Erik T. J. , Rouzée Arnaud
Published: September 2022

We monitor the strong field ionization dynamics of gaseous molecular nitrogen with ultrafast nitrogen K-edge spectroscopy, and resolve initial

N
2
+

electronic state-dependent population distribution following ionization and subsequent fragmentation dynamics.
Roaming in Formaldehyde – and how to get there
Authors: Endo T. , Neville S.P. , Lassonde P. , Qu C. , Fujise H. , Fushitani M. , Hishikawa A. , Houston P.L. , Bowman J.M. , Légaré F. , Schuurman M.S. , Ibrahim H.
Published: September 2022

Roaming molecular fragments in the prototypical formaldehyde dissociation-reaction are directly observed in real-time, using Coulomb explosion imaging and state-of-the-art theoretical modeling. How does the preparation of population ready to roam depend on the pump wavelength?
Ultrafast dynamics of push-pull nitroanilines tracked with few-femtosecond XUV-NIR spectroscopy
Authors: Borrego-Varillas R. , Vismarra F. , Wu Y. , Mocci D. , Holzmeier F. , Reduzzi M. , Recio P. , Cachón J. , González-Vázquez J. , Palacios A. , Santos J. , Lucchini M. , Martín N. , Martín F. , Bañares L. , Nisoli M.
Published: September 2022

The dynamics triggered by photo-ionization in nitroanilines, the simplest donor/ acceptor systems, are investigated with unprecedented temporal resolution. We resolve the role of the donor charge density and the length of the aromatic chain.
Energy- and momentum-visualized ultrafast crossover of photoexcited electron-hole states in 2D semiconductors
Authors: Lin Yi , Chan Yang-hao , Lee Woojoo , Lu Li-Syuan , Li Zhenglu , Chang Wen-Hao , Shih Chih-Kang , Louie Steven G. , Lanzara Alessandra , Kaindl Robert A.
Published: September 2022

By using extreme-ultraviolet time- and angle-resolved photoemission spectroscopy (XUV-trARPES), we visualized the photoemission signature and ultrafast inter-state transitions for the electron-hole plasma and exciton states in monolayer MoS2 with full visions of energy and momentum.
Formation of interlayer excitons in space and time
Authors: Reutzel Marcel , Schmitt David , Bange Jan Philipp , Bennecke Wiebke , AlMutairi AbdulAziz , Meneghini Giuseppe , Watanabe Kenji , Taniguchi Takashi , Steil Daniel , Luke D. Russell , Brem Samuel , Weitz R. Thomas , Steil Sabine , Matthijs Jansen G. S. , Malic Ermin , Hofmann Stephan , Mathias Stefan
Published: September 2022

Excitons modulated by moiré superlattices are a unique model system to explore emergent quantum phases. Here, for the first time, we use time- and angle-resolved photoemission to present unprecedented insight onto the formation dynamics of interlayer excitons in TMD heterostructures with energy-, in-plane momentum, and femtosecond time-resolution.
Direct Observation of the Interlayer Exciton Formation Dynamics in Transition Metal Dichalcogenide Heterostructures
Authors: Policht Veronica R. , Dogadov Oleg , Villa Andrea , Li Qiuyang , Ross Aaron M. , Scotognella Francesco , Zhu Xiaoyang , Dal Conte Stefano , Cerullo Giulio
Published: September 2022

MoSe2/WSe2 transition metal dichalcogenide heterostructures host spatially-indirect interlayer excitons (ILX) following interlayer charge transfer (ICT). We perform ultrafast transient absorption spectroscopy directly probing the ILX formation time and find it to be significantly longer than ICT.
Element Specific Ultrafast Carrier Localization in a 2D Transition Metal Dichalcogenide
Authors: Schumacher Z. , Sato S. A. , Neb S. , Niedermayr A. , Rubio A. , Gallmann L. , Keller U.
Published: September 2022

Ultrafast carrier dynamics in transition metal dichalcogenides can lead to carrier localization in real and k-space. Here, we use attosecond transient absorption to investigate element specific carrier localization in few-layer MoSe2 and its ultrafast response.
Defocus Phase Contrast in Photon-Induced Near-field Electron Microscopy
Authors: Gaida John H. , Lourenco-Martins Hugo , Yalunin Sergey V. , Feist Armin , Sivis Murat , Hohage Thorsten , de Abajo F. Javier García , Ropers Claus
Published: September 2022

We demonstrate optical phase contrast in near-field imaging of metallic nanostructures using a new combination of inelastic electron-light scattering with Fresnel-mode Lorentz microscopy.
Quantum-Coherent Light-Electron Interaction in an SEM
Authors: Chlouba T. , Shiloh R. , Hommelhoff P.
Published: September 2022

Quantum-coherent light-free-electron interaction was shown more than a decade ago in a transmission electron microscope leading to a variety of applications. We now show the quantum-coherent interaction in a scanning electron microscope, offering substantial advantages over TEMs.
Time-Domain Electron Interferometry in an Ultrafast Transmission Electron Microscope
Authors: Tsarev M. , Ryabov A. , Baum P.
Published: September 2022

Bright electron beams have finite temporal coherence due to Pauli exclusion and space-charge effects. We report a time-domain electron interferometer that reveals free-electron coherences in a transmission electron microscope via symmetry-breaking shifts of laser-induced sidebands.
Laser-Controlled Free-Electron Qubits
Authors: Tsarev M. , Ryabov A. , Baum P.
Published: September 2022

We laser-modulate the electron beam of a transmission electron microscope into qubit states for potential use in free-electron quantum optics.
Fourier Transform Photothermal Spectroscopy Detected via AFM for Sub-Diffraction Limit White Light Spectroscopy
Authors: Kunz Miriam Bohlmann , Armstrong Zachary T. , Zanni Martin T.
Published: September 2022

We use an AOM pulse shaper and an AFM to measure absorption spectra with sub-diffraction limit spatial resolution. These experiments were done in the time-domain that utilize ultrafast white light pulses.
Single-Molecule Ultrafast Fluorescence-Detected Pump–Probe Microscopy
Authors: Fersch Daniel , Malý Pavel , Rühe Jessica , Lisinetskii Victor , Hensen Matthias , Würthner Frank , Brixner Tobias
Published: September 2022

We combine fluorescence-detected pump–probe spectroscopy with confocal scanning fluorescence microscopy to investigate the femtosecond dynamics of single terrylene bisimide molecules.
Multimodal vibrational and multi-photon nonlinear optical microscopy to assess chemotherapy-induced senescence in human cancer cells
Authors: Bresci Arianna , Manetti Francesco , Ghislanzoni Silvia , Talone Benedetta , Vernuccio Federico , De la Cadena Alejandro , Ceconello Chiara , Vanna Renzo , Cerullo Giulio , Bongarzone Italia , Polli Dario
Published: September 2022

We introduce label-free multimodal nonlinear optical microscopy, based on different coherent Raman and multi-photon ultrafast light-matter interactions, as a noninvasive, quantitative and chemically selective tool to assess chemotherapy-induced senescence in human cancer cells.
Multiexcitation Global Analysis of Two-dimensional Electronic Spectroscopy of the Bacterial Reaction Center
Authors: Sechrist Riley , Willow Rhiannon , Silori Yogita , Konar Arkaprabha , Ogilvie Jennifer P.
Published: September 2022

We report two-dimensional electronic spectroscopy (2DES) experiments on the bacterial reaction center from purple bacteria mutant W(M250)V, exciting the Qy region and probing multiple spectral regions spanning the visible–mid-IR to extract broadband signatures of charge separation.
Three additional polarizers enable transient absorption spectroscopy to resolve cross peak features like 2D spectroscopy
Authors: Farrell Kieran M. , Zanni Martin T.
Published: September 2022

We demonstrate a polarization scheme, <0°,0°,θ°,-θ°>, that eliminates diagonal peaks and isolates cross peaks. We use the scheme with transient absorption spectroscopy to measure the cross peaks that are often only resolved by 2D spectroscopy.
On-Chip Carrier-Envelope Phase Scanner of Few-Cycle Oscillator Beams
Authors: Hanus Václav , Fehér Beatrix , Pápa Zsuzsanna , Budai Judit , Wang Zilong , Paul Pallabi , Szeghalmi Adriana , Dombi Péter
Published: September 2022

We performed an on-air measurement of CEP spatial distribution of focused few-cycle laser oscillator beam. The on-chip probe exploits the CEP sensitivity of electric currents in dielectrics exposed to the strong field.
All-Solid-State Optical Field Detector using Metal-Insulator Hybrid Nanostructures
Authors: Arai Ko , Okazaki Daiki , Morichika Ikki , Ashihara Satoshi
Published: September 2022

We developed an optical field detector based on plasmon-enhanced field-induced tunneling at a metal-insulator interface. By completely encapsulating metal nanoantennas with dielectric materials, both high photoelectric conversion efficiency and high damage tolerance are achieved.
Tailoring the Impulse Response of Petahertz Optical Field-Sampling Devices
Authors: Ritzkowsky Felix , Bionta Mina R. , Turchetti Marco , Berggren Karl K. , Keathley Philip D. , Kärtner Franz X.
Published: September 2022

Nanoantenna-based petahertz-electronic devices allow tailoring of attosecond fast electron emission currents for optical-field sampling applications. We show how the devices’ symmetry properties can be engineered and electronically controlled to dramatically reconfigure the spectral sampling response.
Coherent control of molecular absorption line shape and optical gain in XUV
Authors: Peng Peng , Mi Yonghao , Lytova Marianna , Britton Mathew , Ding Xiaoyan , Naumov A. Yu. , Corkum P. B. , Villeneuve D. M.
Published: September 2022

We demonstrated coherent control of molecular absorption line shape and optical gain in XUV. The control is achieved by creating a quantum coherence in the ground electronic state of hydrogen molecules.
Driving Ultrafast Control of Photoinduced Anisotropy by Hot Electron Dynamics in Plasmonic Metasurfaces
Authors: Maiuri Margherita , Schirato Andrea , Toma Andrea , Zaccaria Remo Proietti , Nordlander Peter , Cerullo Giulio , Alabastri Alessandro , Valle Giuseppe Della
Published: September 2022

We theoretically predict and experimentally demonstrate by transient absorption spectroscopy that spatiotemporal dynamics of hot electrons can promote and control an ultrafast photoinduced anisotropy in plasmonic metasurfaces, enabling active reconfiguration of the nanostructure nonlinear response.
Coherent optical control of high harmonic generation in monolayer MoS2
Authors: Kozák Martin , Peterka Pavel , Bartoš Miroslav , Trojánek František , Malý Petr
Published: September 2022

We report on experimental study of ultrafast coherent control of high harmonic generation (HHG) in MoS2 monolayers using near-resonant light. We observe suppression of HHG yield caused by nonlinear electron dynamic in two-color fields.
Ultrafast Electron Phase-space Control in a Nanophotonic Structure
Authors: Chlouba T. , Shiloh R. , Illmer J. , Kraus S. , Yousefi P. , Schönenberger N. , Niedermayer U. , Mittelbach A. , Hommelhoff P.
Published: September 2022

We demonstrate ultrafast electron beam phase space control in a silicon-based nanostructure. With this we guide the electron beam through a 225 nm wide and 77 μm channel. This scheme can be applied in chip-based nanophotonic accelerators.
High harmonic lasing using attosecond electron pulses combs in photon-induced near-field electron microscopy
Authors: Pan Yiming , Kaminer Ido , Krueger Michael
Published: September 2022

We propose a new high harmonic lasing mechanism using attosecond electron pulses, which can serve as promising ultra-bright extreme ultraviolet/soft X-ray attosecond laser sources.
Ultrafast phonon dynamics in atomically thin MoS2 visualized in momentum and time
Authors: Britt Tristan L , Li Qiuyang , de Cotret Laurent René , Otto Martin , Hassan Ali Syed , Caruso Fabio , Zacharias Marios , Zhu Xiaoyang , Siwick Bradley J
Published: September 2022

The phonon dynamics and dielectrically screened electron-phonon coupling of atomically thin molybdenum disulfide are directly observed for the first time ever by UEDS diffuse intensity transients in excellent agreement with novel density functional theory calculations.
Phonon-induced valence-charge relocation in cubic BN observed by ultrafast x-ray diffraction
Authors: Woerner Michael , Priyadarshi Shekhar , Gonzalez-Vallejo Isabel , Hauf Christoph , Reimann Klaus , Elsaesser Thomas
Published: September 2022

Femtosecond x-ray powder diffraction reveals the impact of zone-edge TA-phonon excitations on the valence-charge distribution in cubic BN. Transient charge-density maps show a spatial transfer of valence charge from the interstitial region onto boron and nitrogen atoms.
An Ultrafast Source of Attosecond Electron Pulses Triggered by a Surface Plasmon
Authors: Eitan Avraham , Goldner Adi , Krüger Michael
Published: September 2022

We demonstrate a highly coherent ultrafast electron source based on plasmonic nanofocusing using a single groove at the shank of a nanotip. We find signatures of tunneling photoemission, indicating the emission of attosecond electron bursts.
Nonlinear Subcycle Dynamics of Ultrastrong Light-Matter Coupling
Authors: Mornhinweg Joshua , Halbhuber Maike , Ciuti Cristiano , Bougeard Dominique , Huber Rupert , Lange Christoph
Published: September 2022

We drive an ultrastrongly light-matter coupled system by strong, coherent terahertz (THz) waveforms which compete with the resonator vacuum electromagnetic field, leading to strong subcycle nonlinearities including eight-wave mixing and nonlinear polariton correlations.
Ultrafast Two-dimensional Electronic Spectroscopy reveals Phonon-driven Exciton Rabi oscillations in Halide Perovskites
Authors: Nguyen Xuan Trung , Winte Katrin , Timmer Daniel , Rakita Yevgeny , Cahen David , Lorke Michael , Jahnke Frank , Lienau Christoph , De Sio Antonietta
Published: September 2022

We report persistent 100-fs period Rabi oscillations between 1s and 2p excitons in halide perovskite single crystals driven by off-resonant low-frequency phonon modes. This contrasts with prevailing models for the electron-phonon coupling in these materials.
Femtosecond nanoscopy of charge carrier dynamics in van der Waals heterostructures
Authors: Sandner F. , Siday T. , Plankl M. , Faria Junior P. E. , Brem S. , Zizlsperger M. , Perea-Causin R. , Schiegl F. , Nerreter S. , Maier S. , Mooshammer F. , Huber M. A. , Gmitra M. , Fabian J. , Malic E. , Cocker T. L. , Huber R.
Published: September 2022

Ultrafast polarization nanoscopy traces the femtosecond interlayer tunneling and the density-dependent Mott transition of strongly bound excitons in custom-tailored van der Waals heterostructures with subcycle temporal and nanometer spatial resolution.
Multi-Quantum Optical Two-dimensional Coherent Spectroscopy of Many-Body Quantum Coherence
Authors: Li Hebin
Published: September 2022

We have implemented multi-quantum (up to eight-quantum) optical two-dimensional coherent spectroscopy in a collinear setup based on acousto-optic phase modulators. The technique has been demonstrated to detect multi-quantum coherence of up to eight atoms.
Direct Confirmation of the Woodward-Hoffmann Rule by Femtosecond Transient Soft X-ray Absorption
Authors: Sekikawa T. , Saito N. , Kurimoto Y. , Ishii N. , Mizuno T. , Kanai T. , Itatani J. , Saita K. , Taketsugu T.
Published: September 2022

The chemical shifts of the carbon K-edge during the ring-opening dynamics of 1,3-cyclohexadiene observed by femtosecond transient soft X-ray absorption confirm that the stereochemistry of the ring-opening reaction follows the Woodward-Hoffmann rule.
Ring Opening and Rigidity: A Comparison of Time Resolved Photoelectron Spectroscopy Measurements and Calculations for 1,3 -Cyclohexadiene and cis, cis-1,3 - Cyclooctadiene
Authors: McClung Samuel , Liu Yusong , Chakraborty Pratip , Matsika Spiridoula , Weinacht Thomas
Published: September 2022

We compare time resolved photoelectron spectroscopy measurements and trajectory surface hopping calculations for 1,3 - Cyclohexadiene (CHD) and cis,cis-1,3 - Cyclooctadiene (COD). We find qualitative agreement between experiment and theory for both but quantitative agreement only for CHD.
Anisotropic Carrier Dynamics in Graphene Probed with Time- and Angle-Resolved Photoemission Spectroscopy
Authors: Bakalis Jin , Chernov Sergey , Kunin Alice , Li Ziling , Cheng Shuyu , Kawakami Roland K. , Du Xu , White Michael G. , Schönhense Gerd , Allison Thomas K.
Published: September 2022

We report measurements of pump polarization-dependent anisotropy of excited electrons in graphene using time-resolved ARPES. Despite very fast relaxation in energy, the initial anisotropic distributions in momentum space persist through multiple electron-electron and electron-phonon scatterings.
Isolating nonlinear orders of transient grating spectra from a single 2D spectrum
Authors: Rose Peter A. , Lüttig Julian , Malý Pavel , Brixner Tobias , Krich Jacob J.
Published: September 2022

We derive a generic, quantitative relationship between the n-quantum signals observable in 2DES experiments. We use this relationship to isolate individual nonlinear orders free from higher-order contamination, with demonstration on squaraine copolymers.
Young’s type formula for p-s wave interference to determine bond length for hetero-diatomic molecules from PA-MFPADs measurements
Authors: Ota Fukiko , Yamazaki Kaoru , Sébilleau Didier , Ueda Kiyoshi , Hatada Keisuke
Published: September 2022

We have derived a new Young’s formula for the polarization-averaged molecular frame photoelectron angular distributions (PA-MFPADs), as a bond length ruler for dissociating hetero-diatomic molecules. The relative errors against numerical results were within 5%.
Strong-Field Enhanced Ionization of Water using 6-fs Pulse Pairs
Authors: Howard Andrew J. , Britton Mathew , Reynolds Joshua , Gabalski Ian , Forbes Ruaridh , Cheng Chuan , Weinacht Thomas , Bucksbaum Philip H.
Published: September 2022

We demonstrate an enhancement in the formation of D2O3+ as a consequence of field-free molecular dynamics following the strong-field multiple ionization of deuterated water via 6-fs 800-nm pulse pairs.
Holographic Imaging and Reconstruction of Laser-induced Modifications in Thin Films
Authors: Altenkirch Richard , Peltz Christian , Fennel Franziska , Lochbrunner Stefan , Fennel Thomas
Published: September 2022

We present a method for capturing ultrafast laser-induced excitation and relaxation dynamics in thin films via single-shot coherent diffractive imaging. Reference targets were successfully reconstructed from holographic diffraction patterns using a modified phase retrieval approach.
Continuously tunable UV-driven high-intensity HHG source for user applications
Authors: Jurkovič M. , Hort O. , Finke O. , Albrecht M. , Roos A. H. , Hoque Z. , Shaw K. , Klimešová E. , Ltaief L. B. , Andreasson J. , Krikunova M. , Mudrich M. , Antipenkov R. , Grenfell A. , Špaček A. , Szuba W. , Nejdl J.
Published: September 2022

We present experimental results of an intense wavelength-tunable and monochromatic HHG source, applicable for many user applications. We demonstrate this method using the broadband OPCPA and its conversion to UV pump.
Ultrafast XUV Technology Combined with Electrospray Ionization Source for Investigating Large Molecular Ions
Authors: Boyer Alexie , Hervé Marius , Brédy Richard , Compagnon Isabelle , Lépine Franck
Published: September 2022

We present a new experimental set-up combining ultrafast XUV technics with electrospray sources. First results of ultrafast dynamics in large molecular ions are shown demonstrating perspectives for applications in attochemistry.
Generation of High Harmonics and Isolated Attosecond Pulse from MgO
Authors: Chen Zhaopin , Krüger Michael
Published: September 2022

We theoretically investigate attosecond pulse generation from MgO and show that phase-stable two-color femtosecond laser pulses generate a continuous plateau of high harmonics and isolated attosecond pulses with duration as short as 400as.
Femtosecond Soft X-ray Absorption Spectroscopy of Photo-excited NO2
Authors: Zhang Zhuang-Yan , Kleine Carlo , Han Peng , Winghart Marc-Oliver , Vrakking Marc J. J. , Nibbering Erik T. J. , Rouzée Arnaud
Published: September 2022

The femtosecond excitation dynamics of NO2 at 400 nm is investigated by time-resolved soft X-ray absorption spectroscopy at the nitrogen K-edge.
Time-resolved Imaging of Transient Charge Transfer Dynamics
Authors: Allum Felix , Kumagai Yoshiaki , Nagaya Kiyonobu , Harries James , Iwayama Hiroshi , Niozu Akinobu , Ashfold Mike , Britton Mathew , Bucksbaum Philip , Brouard Mark , Burt Michael , Heathcote David , Hockett Paul , Howard Andrew , Kukk Edwin , Lee Jason , Liu Yusong , McManus Joseph , Milesevic Dennis , Minns Russell , Niskannen Johannes , Orr-Ewing Andrew , Rolles Daniel , Rudenko Artem , Ueda Kiyoshi , Unwin James , Vallance Claire , Walmsley Tiffanny , Forbes Ruaridh
Published: September 2022

We study ultrafast charge transfer processes as a function of interfragment separation in dissociating iodopropane molecules using time-resolved site-selective ionization with intense extreme-ultraviolet (XUV) light.
Underdamped longitudinal soft mode dynamics in KDP observed by ultrafast x-ray diffraction
Authors: Gonzalez-Vallejo Isabel , Koç Azize , Reimann Klaus , Woerner Michael , Elsaesser Thomas
Published: September 2022

Ultrafast x-ray powder diffraction reveals a longitudinal underdamped soft mode in paraelectric KDP. Electron density maps derived from the x-ray data demonstrate oscillatory charge relocations over interatomic distances, much larger than the underlying nuclear displacements.
Visualization of the Multi-Center Ultrafast Response in Photoexcited Spinel Co3O4
Authors: Cannelli O. , Restelli S. , Ohannessian N. , Galinetto Pietro , Pergolesi D. , Chergui M. , Mancini G. F.
Published: September 2022

Femtosecond optical and X-ray measurements show excitation-specific ultrafast relaxation processes in spinel Co3O4 thin films. Upon ligand-to-metal and metal-to-metal charge transfer, the system decays through different energy pathways characterized by different coherent and incoherent responses.
Quantum dynamics model of two-quantum two-dimensional electronic spectra of CdSe quantum dots
Authors: Brosseau Patrick , Ramirez Antonio Garzon , Simine Lena , Kambhampati Patanjali
Published: September 2022

We present the characterization of multiexciton interactions in semiconductor CdSe quantum dots through two-dimensional electronic spectroscopy (2DES) and quantum dynamics simulations. Our simulations reproduce the overall shape of the experimental 2DES allowing us to characterize the different species formed.
A Compact, Field-Enhanced RF Gun for Ultrafast Electron Diffraction
Authors: Bazrafshan R. , Fakhari M. , Flöttmann K. , Rohwer T. , Matlis N. H. , Kärtner F. X.
Published: September 2022

We present a novel, compact electron source for a high-temporal-resolution ultrafast electron diffraction (UED) instrument. The source, which employs field-enhancement at a pin-shaped photocathode to allow driving by a solid-state, rack-mountable 10W-average power, 10 kW peak power S-band RF amplifier, can produce 180 keV electron bunches of 100 fC charge that compress via velocity bunching down to 100 fs a distance of 8 cm from the photocathode. A solenoid, following the gun, focuses the electron beam, resulting in a low transverse emittance of 0.1 mm mrad. These specifications make the photogun an ideal source to build a high brightness UED setup with performance surpassing traditional DC-gun-based setups.
Soliton self-compression based HHG driver for water-window transient absorption experiments
Authors: Fazio G. , Balčiūnas T. , Yin Z. , Zimin D. , Brahms C. , Travers J. , Wörner H.J.
Published: September 2022

We present the generation of a supercontinuum soft-X-ray spectrum generated by high-harmonic generation driven by self-compressed 1450 nm pulses using the soliton effect. The compression of 2.8 mJ, 30 fs pulses down to sub 10-fs (supporting 7.2 fs duration) is achieved in a hollow-core fiber and delivered to the HHG target under vacuum using no additional dispersive optics.
Analytical Guidelines to Choose the Right Pressure Profile for High-harmonic Generation in Gas Targets
Authors: Major Balázs , Varjú Katalin
Published: September 2022

We extend the model proposed by Constant and co-workers [PRL 82, 1668 (1999)] to analyze phase matching of high-harmonic generation in gases; and introduce new guidelines to choose the right pressure profile for flux optimization.
Verifying the Frequency Resolved Optical Switching Technique to Accurately Characterize Multi-Octave IR Pulse
Authors: Longa Adrien , Kumar Mayank , Lassonde Philippe , Laramée Antoine , Ibrahim Heide , Legaré François , Leblanc Adrien
Published: September 2022

We present advanced features of the frequency resolved optical switching technique: (i) temporal characterization of an IR supercontinuum, (ii) a high precision on group delay dispersion, (iii) characterization of pulses independently of their polarization direction.
Unified FROG for characterizing 205 nm to 2000 nm, s or p polarization, from 2-cycle to 100 ps
Authors: Wilson Derrek J. , Raffray Antoine , Ramirez Alicia , Kumar Mayank , Longa Adrien , Laramée Antoine , Ibrahim Heide , Légaré François , Schmidt Bruno E.
Published: September 2022

A Frequency Resolved Optical Gating instrument accepting s or p polarized input pulses ranging from 205 nm to 2000 nm, durations from 2 cycles to 100 ps, and nano-Joule energies is presented.
Few-Femtosecond Dynamics of Free-Free Opacity in Optically Heated Metals
Authors: Niedermayr A. , Volkov M. , Sato S. A. , Hartmann N. , Schumacher Z. , Neb S. , Rubio A. , Gallmann L. , Keller U.
Published: September 2022

We investigate non-equilibrium electron dynamics in the free-free absorption window of the simple metal aluminum, heated by a strong near-infrared pump pulse on a few-femtosecond timescale. Experimental results are compared with ab-initio calculations.
Ultrafast Electronic Structural Dynamics of Water-Mediated Photoacid-Base Proton Transfer Reactions
Authors: Winghart Marc-Oliver , Han Peng , Zhang Zhuang-Yan , Mitzner Rolf , Fondell Mattis , Pines Ehud , Odelius Michael , Wernet Philippe , Nibbering Erik T.J.
Published: September 2022

We determine how the transient electronic structure changes of imidazole base upon proton transfer from a naphthol photoacid in aqueous solution can be locally monitored with ultrafast nitrogen K-edge spectroscopy.
Observation of interband Berry phase in laser-driven crystals
Authors: Uzan-Narovlansky Ayelet J. , Faeyrman Lior , Shames Sergei , Narovlansky Vladimir , Xaio Jiewen , Arusi-Parpar Talya , Kneller Omer , Bruner Barry D. , Smirnova Olga , Silva Rui E.F. , Yan Binghai , Jiménez-Galaán Álvaro , Ivanov Misha , Dudovich Nirit
Published: September 2022

We introduce and demonstrate a conceptually new manifestation of the Berry phase in light-driven crystals. We then experimentally demonstrate this phase by using a strong laser field to engineer an internal interferometer, induced during less than one cycle of the driving field, which maps the phase onto the emission of high-order harmonics.
Sub-10fs Photocurrent and Photoluminescence Action Spectroscopies of Organic Optoelectronic Devices Reveals Ultrafast Formation of Bound Excitonic States
Authors: Maimaris Marios , Pettipher Allan J. , Azzouzi Mohammed , Walke Daniel J. , Zheng Xijia , Gorodetsky Andrei , Dong Yifan , Tuladhar Pabitra Shakya , Crespo Helder , Nelson Jenny , Tisch John W. G. , Bakulin Artem A.
Published: September 2022

We apply ultrafast pump-push-photocurrent and pump-push-photoluminescence spectroscopies to polyfluorene organic diode to track in time the bound exciton formation. ‘Cold’-excitons become bound within 10-fs while ‘hot’-excitons can dissociate spontaneously within 50-fs before acquiring bound character.
Ultrafast Energy Transfer and Charge Separation Pathways in the Photosystem II Supercomplex
Authors: Yang Shiun-Jr , Arsenault Eric A. , Orcutt Kaydren , Leonardo Cristina , Iwai Masakazu , Yoneda Yusuke , Fleming Graham R.
Published: September 2022

Spectral congestion challenges spectroscopic studies of the Photosystem II (PSII) light harvesting antenna dynamics. The higher resolution of two-dimensional electronic-vibrational spectroscopy provides new insights into the PSII supercomplex dynamics.
Ultrafast Proton Transfer Pathways Mediated by Imidazole
Authors: Codescu Marius-Andrei , Weiß Moritz , Brehm Martin , Kornilov Oleg , Sebastiani Daniel , Nibbering Erik T. J.
Published: September 2022

We explore with ultrafast infrared spectroscopy and molecular dynamics simulations how imidazole, an amphoteric molecule that can act both as acid and as base, provides alternate proton transfer pathways in the tautomerization reaction of 7-hydroxyquinoline.
Ultrafast Vibrational Relaxation of Excited Free OD at the Air/Water Interface Revealed by Femtosecond Time-Resolved HD-VSFG spectroscopy
Authors: Ahmed Mohammed , Nihonyanagi Satoshi , Tahara Tahei
Published: September 2022

Femtosecond time-resolved HD-VSFG spectroscopy reveals ultrafast
vibrational dynamics of free OD at the air/water interface. The
absence of isotope dilution effect on the vibrational lifetime
suggests that the excited free OD relaxes predominantly through the
reorientation mechanism.
Polarized Phonons Carry Angular Momentum in Ultrafast Demagnetization
Authors: Tauchert S. R. , Volkov M. , Ehberger D. , Kazenwadel D. , Evers M. , Lange H. , Donges A. , Book A. , Kreuzpaintner W. , Nowak U. , Baum P.
Published: September 2022

Ultrafast electron diffraction from nickel reveals that ultrafast demagnetization and the associated Einstein-de Haas effect proceed via polarized phonons and atomic motions on circular trajectories.
Ultrafast magnetization driven by spiral current in Kitaev spin liquid α-RuCl3
Authors: Amano T. , Kawakami Y. , Itoh H. , Aoyama T. , Imai Y. , Ohgushi K. , Nakamura Y. , Kishida H. , Yonemitsu K. , Iwai S.
Published: September 2022

In a honeycomb-lattice Mott insulator α-RuCl3, an ultrafast magnetization is induced by circularly polarized excitation of spin-orbit excitons. An ultrafast 6-fs measurement clarifies that the orbital moment emerges from a coherent inter-orbital charge motion.
Magnetic Helicoidal Dichroism with XUV Light Carrying Orbital Angular Momentum
Authors: Fanciulli M. , Pancaldi M. , Pedersoli E. , Vimal M. , Bresteau D. , Luttmann M. , De Angelis D. , Ribic P. R. , Rösner B. , David C. , Spezzani C. , Manfredda M. , Sousa R. , Prejbeanu I.-L. , Vila L. , Dieny B. , De Ninno G. , Capotondi F. , Sacchi M. , Ruchon T.
Published: September 2022

We report magnetic helicoidal dichroism (MHD) in the interaction between XUV beams carrying orbital angular momentum and magnetic vortices. The results match theoretical predictions and confirm the potential of MHD for studying laser-triggered ultrafast dynamics in complex magnetic materials.
Mapping non-thermal regimes in pump-probe electron relaxation dynamics
Authors: Na Meng Xing , Boschini Fabio , Mills Arthur K. , Michiardi Matteo , Day Ryan P. , Zwartsenberg Berend , Levy Giorgio , Zhdanovich Sergey , Kemper Alexander F. , Jones David J. , Damascelli Andrea
Published: September 2022

Relaxation of photoexcited carriers in graphite is studied by TR-ARPES. Boltzmann rate-equations are used to model the observed non-thermal electron distributions, and several non-thermal phases in the fluence-delay phase space are identified with broad implications.
Disentangling many-body effects in the coherent optical response of a 2D Semiconductor
Authors: Trovatello Chiara , Katsch Florian , Knorr Andreas , Cerullo Giulio , Dal Conte Stefano
Published: September 2022

We fully disentangle Coulomb-induced band-gap renormalization, excitation-induced dephasing and Pauli blocking effects, from the transient optical response of monolayer WS2. A complete picture of the coherent optical response is quantitatively reproduced by microscopic calculations.
A novel ptychographic method for ultrafast exciton dynamics reconstruction
Authors: Dolso Gian Luca , Moio Bruno , Inzani Giacomo , Di Palo Nicola , Borrego-Varillas Rocío , Nisoli Mauro , Lucchini Matteo
Published: September 2022

Excitons determine the ultrafast response of several technologically-relevant materials. Attosecond spectroscopy provides suitable time-resolution, but the access to the exciton response remains non-trivial. We propose a novel, ptychography-based approach to solve this task.
Direct Generation of 4-GW Few-Cycle Visible Pulses in a Large-Core Capillary Fiber
Authors: Piccoli R. , Brown J. M. , Jeong Y.-G. , Rovere A. , Zanotto L. , Gaarde M. B. , Légaré F. , Couairon A. , Travers J. C. , Morandotti R. , Schmidt B. E. , Razzari L.
Published: September 2022

we directly generate 20 µJ, 4.6 fs visible pulses (~2 cycles) without any post-compression by coupling 175-fs-long infrared pulses into a 3-m-long Ar-filled hollow-core fiber and exploiting the nonlinear mixing between its spatial modes.
Self-Dispersion-Managed, Octave-Spanning, Single-Cycle Mid-Infrared Pulse Generator
Authors: Heberle Dylan , Flemens Noah , Lassonde Philippe , Leblanc Adrien , Légaré François , Moses Jeffrey
Published: September 2022

We experimentally demonstrate an octave-spanning mid-IR adiabatic difference-frequency generator that uses monolithic, intrinsic pulse shaping to impart near-zero group-delay dispersion. 13.5-fs 743-nm pulses become 16-fs 2.66-µm pulses with high efficiency and slight residual chirp.
Ultrafast X-Ray hyperspectral imaging of the photo-induced phase transition in VO2
Authors: Johnson A. S. , Pérez-Salinas D. , Siddiqui K. M. , Kim S. , Choi S. , Volckaert K. , Majchrzak P. E. , Ulstrup S. , Hallman K. , Haglund R. F. , Günther C. M. , Pfau B. , Eisebitt S. , Backes D. , Maccherozzi F. , Fitzpatrick A. , Dhesi S. , Gargiani P. , Valvidares M. , Choi H. , Jang D. , Katoch A. , Kwon S. , Park S. H. , Kim H. , Wall S. E.
Published: September 2022

We use the PAL FEL to obtain time and energy-resolved coherent diffractive images of the insulator-metal phase transition in VO2 with femtosecond time, and nanometer spatial resolution, enabling us to directly visualize the phase transition.
Ultrafast time-evolution and recovery of chiral Néel magnetic domain walls probed by x-ray resonant scattering.
Authors: Leveillé Cyril , Burgos-Parra Erick , Sassi Yanis , Ajejas Fernando , Cros Vincent , Chauleau Jean-Yves , Viret Michel , Reyren Nicolas , Jaouen Nicolas
Published: September 2022

Using x-ray resonant magnetic scattering, we report on an ultra-fast change of the magnetic chirality during the first few picoseconds and that at longer timescale magnetic chirality recover faster than the domains magnetization.
Broadband CARS in the fingerprint region at high speed through white-light generation in bulk media
Authors: Vernuccio Federico , Bresci Arianna , Talone Benedetta , De la Cadena Alejandro , Ceconello Chiara , Vanna Renzo , Cerullo Giulio , Polli Dario
Published: September 2022

We demonstrate high-speed broadband CARS microscopy in the fingerprint region generating supercontinuum in a YAG crystal with 2-MHz laser pulses. The system delivers high-quality images of synthetic and biological samples through a novel post-processing pipeline.
Ultrafast transient holography: pump-probe microscopy goes widefield
Authors: Hörmann Martin , Visentin Federico , Zanetta Andrea , Grancini Giulia , van Hulst Niek F. , Liebel Matz , Cerullo Giulio , Camargo Franco V. A.
Published: September 2022

Pump-probe microscopy was limited to single-point detection because cameras are too slow for shot-to-shot demodulation. We use off-axis holography to create an all-optical lock-in camera, obtaining pump-probe images spanning 100×100 μm2. We use it to study exciton diffusion in perovskites around 100 diffraction-limited spots.
Hollow-Core Fiber-Based Transient Absorption Experiment to Probe Ultrafast Relaxation Dynamics in Photosystem I
Authors: Kumar Ajeet , Sebelik Vaclav , Liu Feng , Leister Dario , Hauer Jürgen
Published: September 2022

A hollow-core fiber-based transient absorption experiment for tunable excitation (415-770 nm) and broadband detection (320-1100 nm) is presented and employed on studying ultrafast dynamics in photosystem I.
Reconstruction of Strong-Field-Driven Carrier Generation Dynamics from Injection Harmonics in Solid Dielectrics
Authors: Jürgens Peter , Liewehr Benjamin , Kruse Björn , Peltz Christian , Witting Tobias , Husakou Anton , Rouzeé Arnaud , Ivanov Mikhail , Fennel Thomas , Vrakking Marc J. J. , Mermillod-Blondin Alexandre
Published: September 2022

Non-perturbative low-order harmonics can be dominated by the nonlinearity of strong-field-ionization. We demonstrate the reconstruction of strong-field-driven carrier generation dynamics from ionization-related harmonics in fused silica using a phase-retrieval algorithm.
Hot-charge relaxation in lead halide perovskite: uncovering the bandgap dynamics, hot-biexciton effect and photo-bleaching shift
Authors: Fan Kezhou , Chan Christopher Chang Sing , Yuan Ligang , Yan Keyou , Wong Kam Sing
Published: September 2022

The hot-charge relaxation mechanisms remain contentious in lead halide perovskites, though regarded as frontrunners for future photovoltaics. A model uncovering the spectral and temporal band-edge evolution provides novel insights into many-body interplay and photo-bleaching shift.
Investigation of spectral broadening in different dispersion regimes and low-order harmonic generation in the mid-infrared
Authors: Vaz G. , Pires H. , Hussain M. , Williams G. O. , Fajardo M. , Figueira G.
Published: September 2022

We compare spectral broadening using two lasers at 1.03 µm and 3.2 µm and investigate low-order harmonic generation in solid media in the mid-infrared.
Ultrafast Laser Micromachining in Crystals Using Bessel Beams
Authors: Kuriakose Akhil , Bollani Monica , Di Trapani Paolo , Jedrkiewicz Ottavia
Published: September 2022

Ultrafast laser micromachining in bulk diamond and sapphire has been realized using finite energy Bessel-Gauss beams. The hardness of diamond and crack formation in sapphire have been addressed and tackled using different optimization techniques.
Time Resolve Investigation of the Evolution of Solvation Shell Following Photo-Induced Electron Removal from Halides
Authors: Pan Jaysree , Markmann Verena , Dohn Asmus Ougaard , Haldrup Kristoffer
Published: September 2022

The time-resolved evolution of the solvation shell following photo-induced removal of an electron from halide ions shows strong structural response of water as a solvent to the changes in the charge state of the solute.