We demonstrated a novel optical switch to control the high-order harmonic generation process so that single attosecond pulses can be generated with multiple-cycle pulses. The technique combines two powerful gating methods: polarization and two-color gating. An extreme ultraviolet supercontinuum supporting 130 as was neon gas using 9 fs laser discovered unique dependence of spectra on carrier-envelope phase fields, which repeats every 2 pi radians.

Isolated attosecond pulses are powerful tools for exploring electron dynamics in matter. So far, such extreme ultraviolet have only been generated using high power, few-cycle lasers, which very difficult to construct and operate. We propose demonstrate a technique called generalized double optical gating generating isolated with 20 fs lasers from hollow-core fiber 28 directly an amplifier. These pulses, argon gas, measured be 260 148 as by reconstructing the streaked photoelectron...

Recent progress in sub-laser-cycle gating of high-order harmonic generation promises to push the limits on optical pulse durations below atomic unit time, 24 as, which corresponds a bandwidth broader than 75 eV. However, available techniques for attosecond measurement are valid only narrow-bandwidth spectra, due one key approximations made phase retrieval. Here we report new technique characterizing pulses, whereby spectral is extracted from oscillation component with dressing laser...

Helium atoms in the presence of extreme ultraviolet light pulses can lose electrons through direct photoionization or two-electron excitation followed by autoionization. Here we demonstrate that, combining attosecond with near infrared femtosecond lasers, electron dynamics helium autoionization be not only monitored but also controlled. Furthermore, interference between two ionization channels was modified intense laser pulse. To best our knowledge, this is first time that double and were...

Single isolated attosecond pulses can be extracted from a pulse train with an ultrafast gate in the generation target. By setting width sufficiently narrow generalized double optical gating, we demonstrate that single generated any arbitrary carrier-envelope phase value of driving laser. The only affects photon flux, not duration or contrast. Our results show using unstabilized 23 fs directly chirped amplifiers.

The time delay between the pump and probe pulses in attosecond time-resolved experiments, such as streaking, is commonly introduced by splitting recombining two an interferometer. This technique suffers from instability optical path lengths of arms due to mechanical vibration elements fluctuating environmental conditions. We present a with which unconventional interferometer suppressed while at same controlled within 20 RMS using feedback loop. Using this scheme, streaked spectrogram pulse...

Double optical gating of high-harmonic generation was used to obtain supercontinuous spectra in the extreme UV (XUV) region including water window. The supported a 16 as pulse duration that is below one atomic unit time (24 as). dependence gated on carrier-envelope phase laser provided evidence isolated attosecond pulses were generated. In addition, ensure temporal coherence XUV light, shape and 107 using portion spectrum characterized by streaking.

Using a generalized version of double optical gating, we produced single isolated attosecond pulses with 2-mJ, 25-fs driving lasers. Temporal characterization revealed that the 160-as are accompanied very weak pre- and postpulses. The dependence extreme-ultraviolet spectrum on carrier-envelope phase laser exhibited unique $2\ensuremath{\pi}$ periodicity, indicating robustness subcycle gating.

The attosecond streaking technique is used for the characterization of isolated extreme ultraviolet (XUV) pulses. This type measurement suffers from low photoelectron counts in streaked spectrogram, and thus susceptible to shot noise. For retrieval few- or mono-cycle pulses, high-intensity laser fields are required, which cause energy spectrum above-threshold ionized (ATI) electrons overlap with that photoelectrons. It found by using principal component generalized projections algorithm XUV...

Graphene, a recently discovered two-dimensional form of carbon, is strong candidate for many future electronic devices. There is, however, still much debate over how the properties graphene behave on ultrashort time scales. Here by employing technique time-resolved photoemission, we obtain evolving quantum distributions electrons and holes: an 500 fs scale, electron hole populations can be described two separate Fermi–Dirac distributions, whereas longer scales coalesce to single distribution...

At ${T}_{0}=17.5$ K an exotic phase emerges from a heavy fermion state in URu${}_{2}$Si${}_{2}$. The nature of this hidden order (HO) has so far evaded explanation. Formation unknown quasiparticle (QP) structure is believed to be responsible for the massive removal entropy at HO transition, however, experiments and ab initio calculations have been unable reveal essential character QP. Here we use femtosecond pump-probe time- angle-resolved photoemission spectroscopy (tr-ARPES) elucidate...

We report on a pulsewidth measurement of phase-coherent soft x-ray laser pulses generated by injection seeding solid-target plasma amplifier with high harmonic pulses. A pulse duration $1.13\ifmmode\pm\else\textpm\fi{}0.47\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$ was measured for seeded Ne-like Ti operating at $32.6\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ using an ultrafast streak camera. This is the shortest reported to date from table-top amplifier. The result agrees model simulations which...

Previously, a second harmonic field was added to polarization gating by Mach–Zehnder interferometer gate the high generation process in argon gas. To reduce losses of interferometer, we developed collinear setup consisting only two quartz plates and barium borate crystal. The intensity at focus allowed double optical be performed on neon As result, supercontinuous spectrum produced capable supporting 130as. There is no delay jitter between associated this setup, which necessary for...

Time-resolved photoemission spectroscopy utilizing a probe energy of 32.55 eV and pump 3.1 4.65 with 30 fs temporal resolution is used to study the carrier dynamics in $5f$ Mott insulator uranium dioxide (${\mathrm{UO}}_{2}$). The gap on-site Coulomb interaction energies are measured directly as ${E}_{\text{gap}}=2.5\text{ }\text{ }\mathrm{eV}$ ${U}_{C}=5\text{ }\mathrm{eV}$, respectively, upper Hubbard band mapped. $f\text{\ensuremath{-}}f$Mott-Hubbard involves subpicosecond...

An all optical-fiber-based approach to measuring high explosive detonation front position and velocity is described. By total light return using an incoherent source reflected from a fiber Bragg grating sensor in contact with the explosive, dynamic mapping of versus time obtained. We demonstrate two calibration procedures provide several examples measurements: PBX 9502 cylindrical rate stick, radial 9501, 9501 along curved meridian line. In stick measurement, excellent agreement...

Chirped fiber Bragg grating (CFBG) sensors coupled to high speed interrogation systems are described as robust diagnostic approaches monitoring shock wave and detonation front propagation tracking events for use in energy density physics applications. Taking advantage of the linear distributed spatial encoding spectral band single-mode CFBGs, embedded associated photonic methodologies shown an effective approach sensing detonation-driven loading processes along CFBG length. Two approaches,...

The combination of polarization gating and two-color is a promising approach to generate single isolated attosecond pulses with multicycle pump lasers. We searched the phase-matching conditions for high-order harmonic generation such double optical using $0.85\phantom{\rule{0.3em}{0ex}}\mathrm{mJ}$, $8\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$ laser centered at $790\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. At optimized gas target location pressure, extreme ultraviolet pulse energy...

Measuring detonation wavefront position and velocity changes across material interfaces has been demonstrated using an all-optical chirped fiber Bragg grating approach. An experiment was conducted with a cylindrical rate stick consisting of multiple high explosive (HE) segments. A measurement different HE formulations made for both low spatial resolution gratings. The results show the accuracy measured velocities is increased higher decaying shock driven into polymethyl methacrylate (PMMA)...

We have measured the pulse duration of gain-saturated 13.9 nm Ni-like Ag and 13.2 Cd transient collisional lasers excited by grazing-incidence-pumping for several pumping conditions. High-resolution streak-camera measurements yielded FWHM durations close to 5 ps both under optimum The very high brightness short these new repetition tabletop soft x-ray make them an attractive source dynamic applications.

Previously a two-color field was combined with polarization gating to allow for the generation of single isolated attosecond pulses from multicycle lasers. Here, scaling energy extreme ultraviolet corresponding as function input laser pulse duration investigated argon, neon, and helium gas. Laser long 12 fs were able generate supercontinua high photon flux. The spectra profile depended strongly on carrier envelope phase pump laser.

Abstract Grating‐based chirped pulse amplifiers are the cornerstone of high‐power femtosecond lasers. The amplification carrier‐envelope phase stable pulses in such lasers has only been realized within last few years. Currently, state‐of‐the‐art this endeavor is utilizing change grating separation stretcher or compressor. drift can be reduced to 160 mrad RMS level and swept a 2 π range. effects laser energy stability on f‐to‐2f measurement were found significant, with 1% leading error,...

Previously, we demonstrated the stabilization of carrier-envelope (CE) phase laser pulses from a chirped pulse amplifier by controlling effective grating separation in stretcher. In this work, show that CE can also be stabilized to ∼230mrad compressor. The cutoff frequency piezoelectric transducer mounted for system was found higher than 60Hz.

A hallmark in the cuprate family of high-temperature superconductors is nodal-antinodal dichotomy. In this regard, angle-resolved photoemission spectroscopy (ARPES) has proven especially powerful, providing band structure information directly energy-momentum space. Time-resolved ARPES (trARPES) holds great promise adding ultrafast temporal information, an attempt to identify different interaction channels time domain. Previous studies cuprates using trARPES were handicapped by low probing...

Previously, pulses shorter than 4 fs were generated by compressing white light from gas-filled hollow-core fibers with adaptive phase modulators; however, the energy of few-cycle was limited to 15 microJ. Here, we report generation 550 microJ, 5 using a liquid crystal spatial modulator in grating-based 4f system. The high pulse obtained improving throughput and increasing input laser energy. When used harmonic generation, it found that spectra depend strongly on order spectral phases driving fields.

An all optical-fiber-based approach to measuring high explosive detonation front position and velocity is demonstrated. By total light return using an incoherent source reflected from a fiber Bragg grating sensor in contact with the explosive, dynamic mapping of versus time obtained. We demonstrate two examples measurements: PETN detasheet test along multi-HE cylindrical rate stick containing sections PBX 9501, Comp B, TNT, 9407, 9520, inert PMMA. In measurement, excellent agreement...