A5070335983- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Terahertz technology and applications
- Photonic Crystal and Fiber Optics
- Silicon Nanostructures and Photoluminescence
- Semiconductor materials and devices
- Laser-Plasma Interactions and Diagnostics
- Plasmonic and Surface Plasmon Research
- Semiconductor Quantum Structures and Devices
- Metamaterials and Metasurfaces Applications
- Electron and X-Ray Spectroscopy Techniques
- Advanced Electron Microscopy Techniques and Applications
- Solid State Laser Technologies
- Quantum optics and atomic interactions
- Strong Light-Matter Interactions
- Superconducting and THz Device Technology
- Spectroscopy and Quantum Chemical Studies
- Photonic and Optical Devices
- Photocathodes and Microchannel Plates
- Laser Design and Applications
- Near-Field Optical Microscopy
- Laser-induced spectroscopy and plasma
- Nonlinear Photonic Systems
- Crystallography and Radiation Phenomena
- Advanced X-ray Imaging Techniques
Fudan University
2007-2025
State Key Laboratory of Surface Physics
2019-2025
MetaMateria (United States)
2024-2025
Hefei Institutes of Physical Science
2023
Anhui University
2023
Joint Institute for Laboratory Astrophysics
2019
Michigan State University
2009-2015
Nanjing University
2008
Dynamically controlling terahertz (THz) waves with an ultracompact device is highly desired, but previously realized tunable devices are bulky in size and/or exhibit limited light-tuning functionalities. Here, we experimentally demonstrate dynamic modulation on THz a dielectric metasurface mode-selective or mode-unselective manners through pumping the system at different optical wavelengths. Quasi-normal-mode theory reveals that physics governed by spatial overlap between wave functions of...
In this Letter, we investigate the energy-scaling rules of hollow-core fiber (HCF)-based nonlinear pulse propagation and compression merged with high-energy Yb-laser technology, in a regime where effects such as plasma disturbance, optical damages, setup size become important limiting parameters. As demonstration, 70 mJ 230 fs pulses from Yb laser amplifier were compressed down to 40 25 by using 2.8-m-long stretched HCF core diameter 1 mm, resulting record peak power 1.3 TW. This work...
Abstract Generating intense ultrashort pulses with high-quality spatial modes is crucial for ultrafast and strong-field science can be achieved by nonlinear supercontinuum generation (SCG) pulse compression. In this work, we propose that the of quasi-stationary solitons in periodic layered Kerr media greatly enhance light-matter interaction fundamentally improve performance SCG compression condensed media. With both experimental theoretical studies, successfully identify these solitary...
Abstract Structured light, particularly in the terahertz frequency range, holds considerable potential for a diverse range of applications. However, generation and control structured radiation pose major challenges. In this work, we demonstrate novel programmable spintronic emitter that can flexibly generate variety waves. This is achieved through precise high-resolution programming magnetization pattern on emitter’s surface, utilizing laser-assisted local field cooling an exchange-biased...
Understanding space charge effects is central for the development of high-brightness ultrafast electron diffraction and microscopy techniques imaging material transformation with atomic scale detail at fs to ps timescales. We present methods results direct photoelectron beam characterization employing a shadow projection technique investigate generation ultrafast, non-uniform, intense pulses in dc photo-gun geometry. Combined N-particle simulations an analytical Gaussian model, we elucidate...
Abstract The emerging use of two-dimensional (2D) nanomaterials as boundary lubricants in water offers numerous benefits over oil-based lubricants; whereas the friction reduction varies significantly with nanomaterial type, size, loading, morphology, etc. Graphene oxide (GO) and Ti 3 C 2 T x MXene, a relatively new 2D material, are investigated this study. contact pair mainly includes Si N 4 balls wafer. results found (1) monodispersed GO better lubricity than MXene under identical...
Abstract Quantum-state manipulation through coherent interaction with a radiation field is fundamental process broad implications in quantum optics and information processing. However, current control methods are limited by their operation at Rabi frequencies below the gigahertz range, which restricts applicability to systems long coherence times. To overcome this limitation, alternative approaches utilizing ultrafast driving lasers have garnered great interest. In work, we demonstrate...
Plasmonic nanoantennas, which support surface plasmon resonances enabling the concentration of electromagnetic energy into subwavelength volumes, have emerged as versatile tools for a wide range applications. However, achieving high-resolution near-field imaging with polarization and temporal sensitivity remains significant challenge. In this work, we present novel nonlinear optical microscopy technique based on degenerate four-wave mixing to enable spectrum- polarization-resolved plasmonic...
By employing two-color counterrotating circularly polarized laser fields, we investigate the dynamics of electron recapture into Rydberg states under strong, ultrashort pulses, probed via coherent extreme-ultraviolet free-induction decay (XFID). Our study reveals significant distinctions between XFID and above-threshold high-order harmonic generation in terms their ellipticity dependence on driving-laser waveforms, yield variations with laser-intensity ratios, sensitivity to ellipticity. All...
The ability to generate and manipulate broadband chiral terahertz waves is essential for applications in material imaging, sensing, diagnosis. It can also open up new possibilities nonlinear spectroscopy coherent control of molecules magnetic materials. existing methods, however, often suffer from low efficiency, narrow bandwidth, or poor flexibility. Here, we propose a novel type laser-driven emitters, consisting metasurface-patterned multilayer heterostructures, that overcome the...
The high power and variable repetition-rate of Yb femtosecond lasers makes them very attractive for ultrafast science. However, capturing sub-200 fs dynamics, efficient, high-fidelity high-stability pulse compression techniques are essential. Spectral broadening using an all-solid-state free-space geometry is particularly attractive, as it simple, robust low-cost. spatial temporal losses caused by spatio-spectral inhomogeneities have been a major challenge to date, due coupled space-time...
The demand for emerging applications at the terahertz frequencies motivates development of novel and multifunctional devices generation manipulation waves. In this work, we report realization spintronic-metasurface emitters, which allow simultaneous beam-steering full polarization control over a broadband beam. This is achieved through engineering individual meta-atoms with nanoscale magnetic heterostructures and, thus, implementing microscopical laser-induced spin charge dynamics. By...
Development of ultrafast table-top x-ray sources that can map various spin, orbital, and electronic configurations reordering processes on their natural time length scales is an essential topic for modern condensed matter physics as well science. In this work, we demonstrate spatiotemporally resolved resonant magnetic scattering (XRMS) to probe the inner-shell 4d electrons a rare-earth (RE) composite ferrimagnetic system using bright <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"...
Understanding dephasing mechanisms of strong-field-driven excitons in condensed matter is essential for their applications quantum-state manipulation and ultrafast optical modulations. However, experimental access to exciton under strong-field conditions challenging. In this study, using time- spectrum-resolved quantum-path interferometry, we investigate the terahertz-driven excitonic Autler-Townes doublets MoS_{2}. Our results reveal a dramatic increase rate beyond threshold field strength,...
We present an electron projection imaging method to study the ultrafast evolution of photoelectron density distribution and transient fields near surface. The dynamical profile photoelectrons from graphite reveals origin a thermionic emission, followed by adiabatic process leading acceleration cooling before freely expanding cloud is established. hot emission found couple with surface charge dipole layer formation, sheet several orders magnitude higher than that vacuum emitted cloud.
We demonstrate an efficient approach for enhancing the spectral broadening of long laser pulses and frequency redshifting by exploiting intrinsic temporal properties molecular alignment inside a gas-filled hollow-core fiber (HCF). find that laser-induced with durations comparable to characteristic rotational time scale TRotAlign enhances efficiency redshifted compared noble gases. The applicability this Yb lasers (few hundred femtoseconds) pulse duration is illustrated, which based on...
The concept of critical ionization fraction has been essential for high-harmonic generation, because it dictates the maximum driving laser intensity while preserving phase matching harmonics. In this work, we reveal a second, nonadiabatic fraction, which substantially extends phase-matched harmonic energy, arising strong reshaping intense field in gas plasma. We validate understanding through systematic comparison between experiment and theory wide range conditions. particular, properties...
Using a multilevel fast multipole method, coupled with the shadow imaging of femtosecond photoelectron pulses for validation, we quantitatively elucidate photocathode, space charge, and virtual cathode physics, which fundamentally limit spatiotemporal spectroscopic resolution throughput ultrafast electron microscope (UEM) systems. We present simple microscopic description to capture nonlinear beam dynamics based on two-fluid picture an unexpected dominant role image potential pinning in...
Precise and ultrafast control over photo-induced charge currents across nanoscale interfaces could lead to important applications in energy harvesting, electronics, coherent terahertz sources. Recent studies have shown that several relativistic mechanisms, including inverse spin-Hall effect, Rashba–Edelstein spin-orbit-torque can convert longitudinally injected spin-polarized from magnetic materials transverse currents, thereby harnessing these for generation. However, mechanisms typically...
In this letter, we report on the characteristics of 1.54μm photoluminescence emission Er-doped HfO2 films synthesized by pulsed laser deposition and ion implantation. An efficient at in annealed has been observed under a broad band excitation from 400nm to higher energy room temperature. X-ray diffraction electron paramagnetic resonant measurements were used analyze correlation between optical properties microstructures. transfer mechanism is proposed that O vacancy bulk acts as an effective...
High-order sideband generation (HSG) in semiconductors under intense terahertz fields has been extensively studied, because it provides essential information for studying ultrafast dynamics strong-field-dressed quantum materials. In particular, transition metal dichalcogenides (TMDCs), characterized by their unique band structures, provide an exemplary semiconductor system to explore the influence of material structure on strong-field-induced modulation HSG. this work, we investigate...
All-dielectric optical resonators, exhibiting exotic near-field distributions upon excitations, have emerged as low-loss, versatile and highly adaptable components in nanophotonic structures for manipulating electromagnetic waves enhancing light-matter interactions. However, achieving experimental full three-dimensional characterization of near-fields within dielectric materials poses significant challenges. Here, we develop a novel technique using high-order sideband generation to image...
The temperature and the power dependent photoluminescence (PL) of two types Ge quantum dots (QDs) (small hut cluster large dome) coincidentally grown on a strained Si0.7Ge0.3 buffer layer were systematically studied. Two PL peaks from QDs are demonstrated show different behaviors with increasing temperature. Under low excitation power, intensity energy position peak small have maximum values at mediate Such anomalous spectra qualitatively explained by model based thermally activated resonant...