Low-frequency currents induced by ultrashort laser-driven ionization can emit extremely broadband, single-cycle terahertz pulses. We present a model that predicts strong wavelength dependence of the THz emission in good agreement with our experimental study. This reveals combined effects plasma rising proportionally to square pump and wavelength-dependent focusing conditions lead 30 times higher at 1800 nm compared an 800 wavelength. Unrivaled electric field strengths 4.4 MV/cm are achieved...

In this paper, we will review both past and recent progresses in the generation, detection application of intense terahertz (THz) radiation. We restrict to laser based few-cycle THz sources, thus not include sources such as synchrotron-based or narrowband sources. first various methods used for generating radiation, including photoconductive antennas (PCAs), optical rectification (especially tilted-pulse-front lithium niobate source DAST source, but also those using other crystals), air...

We demonstrate the generation muJ-level, single-cycle terahertz pulses by optical rectification from a large-aperture ZnTe single crystal wafer. Energies up to 1.5 muJ per pulse and spectral range extending 3 THz were obtained using 100 Hz Ti:sapphire laser source 75-mmdiameter, 0.5-mm-thick, (110) crystal, corresponding an average power of 150 muW energy conversion efficiency 3.1 x 10(-5). also real-time imaging focused beam pyroelectric infrared camera.

Metamaterial induced transparency is demonstrated using individual split ring resonators with two gaps on opposite side. For the symmetric structure, only a low quality dipolar resonance witnessed at normal incidence excited electric field along resonator gaps. Displacement of one gap from centre breaks symmetry and higher order mode, inaccessible in excited. Coherent interaction among modes forms an extremely sharp narrowband window centred directly dipole resonance. Such metamaterial could...

We report the demonstration of strong resonance enhancement a single high-order harmonic in extreme ultraviolet (XUV) region generated from interaction femtosecond pulse with low-ionized In ablation. A 13th (61.2 nm) Ti:sapphire laser radiation output intensity almost two orders magnitude higher than neighboring harmonics was observed these studies. The high conversion efficiency (8 x 10(-5)) is attributed to multiple collisions electron trajectories origin due multiphoton ion.

Today's ultrafast lasers operate at the physical limits of optical materials to reach extreme performances. Amplification single-cycle laser pulses with their corresponding octave-spanning spectra still remains a formidable challenge since universal dilemma gain narrowing sets for both real level pumped amplifiers as well parametric amplifiers. We demonstrate that employing amplification in frequency domain rather than time opens up new design opportunities science, potential generate...

We report on a novel metamaterial structure that sustains extremely sharp resonances in the terahertz domain. This system involves two conductively coupled split ring resonators together exhibit resonance, broad analogy to antiphase mode of so-called Huygens pendulum. Even though this resonance is principle forbidden each individual symmetric ring, our experiments show new can sustain quality factors are more than one order magnitude larger those conventional arrangements. Because...

Using a 400 μJ ytterbium laser combined with novel pulse compression technique, we demonstrate state-of-the-art terahertz (THz) source from the tilted-pulse front pumping scheme in lithium niobate at room temperature record efficiency of 1.3% capable generating 74 mW average power and kV/cm focus. Key points this demonstration include use pump duration 280 fs combination stair-step echelon mirror an off-axis ellipsoidal mirror. This has unmatched characteristics intense powerful THz pulses...

Single-pixel imaging (SPI) has emerged as a powerful technique that uses coded wide-field illumination with sampling by single-point detector. Most SPI systems are limited the refresh rates of digital micromirror devices (DMDs) and time-consuming iterations in compressed-sensing (CS)-based reconstruction. Recent efforts overcoming speed limit SPI, such use fast-moving mechanical masks, suffer from low reconfigurability and/or reduced accuracy. To address these challenges, we develop...

We use an open-aperture $Z$ scan technique to show how intense few-cycle terahertz pulses can experience a nonlinear bleaching of absorption in $n$-doped semiconductor due terahertz-electric-field-driven intervalley scattering electrons the conduction band. Coherent detection transmitted pulse wave form also allows conductivity dynamics be followed with subpicosecond time resolution. Both and time-domain results are found agreement our theoretical analysis.

We demonstrate, for the first time, high-order harmonic generation from C60 by an intense femtosecond Ti:sapphire laser. Laser-produced plasmas C60-rich epoxy and films were used as nonlinear media. Harmonics up to 19th order observed. The yield fullerene-rich plasma is about 25 times larger compared with those produced a bulk carbon target. Structural studies of debris confirm presence integrity fullerenes within plume, indicating source harmonics.

The development of new sources in the terahertz (THz) spectral region has attracted much attention over past 20 years. In particular, last three years have seen a surge laser-based techniques for generating intense, few-cycle THz pulses microjoule energy range, thus paving way to study nonlinear optical properties various materials at frequencies. Simultaneously, innovative solutions broad-band detection were found, allowing one sense matter range with an unprecedented time resolution. this...

Nonlinear transient absorption bleaching of intense few-cycle terahertz (THz) pulses is observed in photoexcited GaAs using opticalpump--THz-probe techniques. A simple model the electron transport dynamics shows that nonlinear response due to THz-electric- field-induced intervalley scattering over sub-picosecond time scales as well an increase intravalley rate attributed carrier heating. Furthermore, nature THz pulse transmission at high peak fields leads a measured conductivity deviates...

We present the first measurement of attosecond emission generated from underdense plasma produced on a solid target.We generate high-order harmonics femtosecond Ti:sapphire laser focused in weakly ionized chromium plasma.Using "Reconstruction Attosecond Beating by Interference Two-photon Transitions" (RABITT) technique, we show that 11 th to 19 harmonic orders form time domain an pulse train with each having 300 as duration, which is only 1.05 times theoretical Fourier transform...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Ibraheem Al-Naib, Ranjan Singh, Carsten Rockstuhl, Falk Lederer, Sebastien Delprat, David Rocheleau, Mohamed Chaker, Tsuneyuki Ozaki, Roberto Morandotti; Excitation of a high-Q subradiant resonance mode in mirrored single-gap asymmetric split ring resonator terahertz metamaterials. Appl. Phys. Lett. 13 August...

Abstract In high-order harmonic generation, resonant harmonics (RH) are sources of intense, coherent extreme-ultraviolet radiation. However, intensity enhancement RH only occurs for a single order, making it challenging to generate short attosecond pulses. Moreover, the mechanism involved behind such was circumstantial, because lack direct experimental proofs. Here, we demonstrate exact quantum paths that electron follows generation using tin, showing involves not autoionizing state, but...

The nonlinear interaction of subcycle electromagnetic radiation with matter is the current frontier in ultrafast optics and high-field physics. Here, we investigate optical effects induced by intense, terahertz a doped semiconductor. We observe truncation half-cycle pulse an emission high-frequency photons. attribute our observations to abrupt drop caused strong intervalley scattering effects. By adding extra opposite polarity, monitor evolution carrier dynamics during quasi-single-cycle...

We have successfully demonstrated intensity enhancement of a single high-order harmonic at wavelength 46.76 nm by using low-ionized tin ions in laser-ablation plume as the nonlinear medium. The ablation was produced irradiating solid target with 10 mJ energy picosecond laser pulse. Strong 17th-harmonic generation observed conversion efficiency about 10(-4). attribute strong to multiphoton resonance radiative transition Sn II ion.

We demonstrate the generation of up to 63rd harmonic (?=12.6?nm) a Ti:sapphire laser pulse (150?fs,10?mJ), using prepulse- (210-ps,24-mJ) produced boron plasma as nonlinear medium. The influence various parameters on conversion efficiency was analyzed. steep decrease in intensity for low-order harmonics (up 19th order) followed by plateau. Typical efficiencies were evaluated be 10?4 (for 3rd harmonic) 10?7 (within plateau region). Harmonic appeared efficient that comprised neutral atoms and...

We present experimental studies of high-order harmonic generation in silver plasma ablation performed with the Ti:sapphire laser beams Advanced Laser Light Source ($800\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ wavelength, $360\phantom{\rule{0.3em}{0ex}}\mathrm{mJ}$ total energy). have independently varied intensity prepulse (which creates ablation) and main pulse generates harmonics), studied their influence on spectrum. show here that presence doubly ionized atoms ablation, created either by...

We demonstrate the generation of 101st harmonic (wavelength $\ensuremath{\lambda}=7.9\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$) from manganese plasma, which is generated using plasma high-order technique. also investigate variation distribution plume as a function prepulse and main pulse intensities. The cutoff was at 31st order, for pump intensities below barrier suppression intensity singly charged Mn ions. However, by higher intensities, extended to with an appearance second plateau...

Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation Y. Pertot, L. B. Elouga Bom, V. R. Bhardwaj, T. Ozaki; Pencil lead plasma for generating multimicrojoule high-order harmonics with a broad spectrum. Appl. Phys. Lett. 7 March 2011; 98 (10): 101104. https://doi.org/10.1063/1.3558999 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley...

We demonstrate intense high-order harmonic generation from plasma that is created different carbon targets. obtain energy in the multi-microjoule range for each order 11th to 17th harmonic. By analyzing target morphology and composition, we conclude harmonics bulk targets originate nanoparticles target.

We demonstrated continuum high-order harmonics from carbon plasma using the double optical gating method. The extreme ultraviolet covered 17–25 eV. observation of such is first step towards generation high-flux single attosecond pulses harmonics.