A5032889058- Laser-Matter Interactions and Applications
- Advanced Fiber Laser Technologies
- Solid State Laser Technologies
- Photorefractive and Nonlinear Optics
- Photonic Crystal and Fiber Optics
- Spectroscopy and Quantum Chemical Studies
- Laser-Plasma Interactions and Diagnostics
- Topological Materials and Phenomena
- Acoustic Wave Resonator Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
- Atomic and Molecular Physics
- Gas Dynamics and Kinetic Theory
- Laser Design and Applications
- Graphene research and applications
- Ion-surface interactions and analysis
- Nonlinear Optical Materials Research
- Nonlinear Photonic Systems
- Laser Material Processing Techniques
- Advanced Condensed Matter Physics
- Electron and X-Ray Spectroscopy Techniques
- Advanced Thermoelectric Materials and Devices
- Optical and Acousto-Optic Technologies
- Photonic and Optical Devices
- Terahertz technology and applications
- Mass Spectrometry Techniques and Applications
The Ohio State University
2025
University of California, Berkeley
2022-2024
University of Central Florida
2016-2023
Photonics (United States)
2020
We generate high-order harmonics in a-cut (11–20) ZnO at a high repetition rate of 50 kHz, using the tunable mid-infrared pulses (3–4 μm wavelength) from high-power optical parametric amplifier. For driving laser with 3.8 central wavelength, we observe nonperturbative harmonic spectra that well exceed material band gap. The depend strongly on orientation crystal respect to polarization, odd exhibiting periodicities π/2 for polarization within plane. Energy conversion efficiencies ∼10−6 per...
Molecular gases enable extreme compression of industrial-grade lasers, providing a more accessible platform for attosecond science.
We investigate the potential of a multi-plate medium consisting thin fused silica plates to generate few-cycle pulses from moderately high energy (400 μJ) and average power (20 W) Yb:KGW laser centered at 1025 nm. By optimizing thicknesses positions plates, we mitigate losses associated with spatial spectral distortions that can accompany self-focusing in bulk solids. Pulses an initial duration ∼280 fs were compressed using chirped mirrors, after broadening 6 mm total, by factor >5 50...
Recent developments in ultrafast laser technology have resulted novel few-cycle sources the mid-infrared. Accurately characterizing time-dependent intensities and electric field waveforms of such pulses is essential to their applications strong-field physics attosecond pulse generation, but this remains a challenge. Recently, it was shown that tunnel ionization can provide an temporal “gate” for high-energy capable ionizing air. Here, we show tunneling multiphoton excitation dielectric solid...
The NSF NeXUS user facility is designed to enable direct observation of electron motion with attosecond femtosecond time resolution, angstrom spatial and element-specific spectral resolution. will level the scientific playing field by providing researchers across disciplines access most advanced characterization tools available worldwide for studying ultrafast dynamics in molecules materials.
Few-cycle, long-wavelength sources for generating isolated attosecond soft x ray pulses typically rely upon complex laser architectures. Here, we demonstrate a comparatively simple setup sub-two-cycle in the short-wave infrared based on multidimensional solitary states an N2O-filled hollow-core fiber and two-channel light-field synthesizer. Due to temporal phase imprinted by rotational nonlinearity of molecular gas, redshifted (from 1.03 1.36 µm central wavelength) supercontinuum generated...
High-repetition-rate high-harmonic sources are desired for novel attosecond and time-resolved spectroscopies. One route to generating these is the nonlinear compression of high-average power Yb fiber solid-state amplifiers, which can achieve >100 fs pulse duration with microjoule millijoule energy. Here, we demonstrate 280 fs, 400 μJ pulses from a moderately high (20 W) Yb:KGW laser amplifier 15 fs. Few-cycle (<5 cycles) an energy up 200 obtained relatively simple scheme utilizing...
We carried out a joint theoretical and experimental study of the polarization high-order harmonics generated from ZnO by intense infrared laser pulses. Experimentally we found that dependence parallel perpendicular polarizations on crystal orientation for all odd are nearly identical, but they quite different even which also show little order dependence. A one-dimensional two-band model, combined with linear coupled excitation is shown to be able explain observed behavior, including...
Characterizing and controlling electronic properties of quantum materials require direct measurements non-equilibrium band structures over large regions momentum space. Here, we demonstrate an experimental apparatus for time- angle-resolved photoemission spectroscopy using high-order harmonic probe pulses generated by a robust, moderately high power (20 W) Yb:KGW amplifier with tunable repetition rate between 50 150 kHz. By driving generation (HHG) the second fundamental 1025 nm laser...
Few-cycle sources with high average powers are required for applications to attosecond science. Raman-enhanced spectral broadening of Yb-doped laser amplifiers in molecular gases can yield few-cycle pulses, but thermal excitation vibrational and rotational degrees freedom may preclude high-power operation. Here we investigate changes the associated repetitive interactions an <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mrow class="MJX-TeXAtom-ORD">...
Progress in attosecond science has relied on advancements few-cycle pulse generation technology and its application to high-order harmonic generation. Traditionally, self-phase modulation bulk solids been used for the compression of moderate-energy pulses, additionally exhibiting favorable dispersion properties mid-infrared (mid-IR) pulses. Here, we use anomalous Y3Al5O12 (YAG) self-compress many-cycle pulses from a 50 kHz mid-IR OPA down produce sub-three-cycle 10 μJ further them generate...
Abstract Recently, nodal line semimetals based on ZrSiS-family have garnered massive research interests contributing numerous experimental and theoretical works. Despite being the most studied nodal-line semimetal, a clear understanding of transient state relaxation dynamics underlying mechanism in ZrSiS is lacking. Using time- angle-resolved photoemission spectroscopy, we study ultrafast reveal unique bulk which well-captured by simple model optical acoustic phonon cooling. Our predicts...
We generate high-order harmonics from femtosecond mid-IR pulses in ferroelectric BaTiO3 crystals. find that odd and even harmonics' intensity polarization behave differently when rotating the input with respect to crystal axes.
A coherent vibrational wavepacket is launched and manipulated in the symmetric stretch (a$_1$) mode of CBr$_4$, by impulsive stimulated Raman scattering from non-resonant 400 nm laser pump pulses with various peak intensities on order tens 10$^{12}$ W/cm$^2$. Extreme ultraviolet (XUV) attosecond transient absorption spectroscopy (ATAS) records dynamics as temporal oscillations XUV energy at bromine M$_{4,5}$ 3d$_{3/2,5/2}$ edges around 70 eV. The results are augmented nuclear time-dependent...
A coherent vibrational wavepacket is launched and manipulated in the symmetric stretch (a1) mode of CBr4, by impulsive stimulated Raman scattering (ISRS) from nonresonant 400 nm laser pump pulses with various peak intensities on order tens 1012 W/cm2. Extreme ultraviolet (XUV) attosecond transient absorption spectroscopy (ATAS) records dynamics as temporal oscillations XUV energy at bromine M4,5 3d3/2,5/2 edges around 70 eV. The results are augmented nuclear time-dependent Schrödinger...
Spectral narrowing and power reduction, resulting from the thermal effect of nonlinear molecules at high repletion rate, can be mitigated by adding helium buffer-gas in N 2 O-filled hollow-core fiber without changing spectral phase.
We demonstrate a novel trARPES setup using high-order harmonic probe pulses produced from moderately high power Yb: KGW amplifier. The surface band structure of Zr2Te2P is measured single at 21.8 eV.
We demonstrate that tunneling and multiphoton excitation in a dielectric solid can provide an ultrafast temporal “gate” for characterizing high-energy, few-cycle waveforms. Using this technique, near- mid-infrared pulses are measured.
We generate high-order harmonics in ZnO using a mid-IR OPA with 50 kHz repetition rate. Nonperturbative harmonic spectra beyond the band gap exhibit strong dependence on crystal orientation respect to laser polarization.
Octave-spanning spectra centered at 1.4 µm are generated by Raman-enhanced spectral broadening of a Yb:KGW amplifier in N 2 O-filled hollow-core fiber and compressed to 1.5 cycles two-channel synthesizer using only bulk materials for compression.