Two collinear femtosecond laser pulses, one at wavelength of $800\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ and the other $400\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ (double frequency), simultaneously irradiated surface ZnSe crystal, which resulted in regular nanograting with period $180\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$ on whole ablation area. We attribute formation to be due interference between scattered wave lasers light. The $\ensuremath{\Lambda}$ is about $\ensuremath{\lambda}∕2n$,...

Get PDF Email Share with Facebook Tweet This Post on reddit LinkedIn Add to CiteULike Mendeley BibSonomy Citation Copy Text Toshiaki Kita, Tatsuo Harada, N. Nakano, and H. Kuroda, "Mechanically ruled aberration-corrected concave gratings for a flat-field grazing-incidence spectrograph," Appl. Opt. 22, 512-513 (1983) Export BibTex Endnote (RIS) HTML Plain alert Save article

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.

A new type of grazing-incidence spectrometer with a flat focal field is developed, and XUV spectroscopy in the extreme ultraviolet region ranging from 15 to 200 Å carried out. Soft x-ray line spectra emitted picosecond laser plasmas aluminum iron targets are measured good resolutions obtained region. The spectral regions detection extended shorter wavelengths (15 Å) using finer spaced grating. Computational studies on also performed taking into account transient characteristics...

We investigate third- and higher-order nonlinear optical processes in Au, Pt, Pd, Ru nanoparticles. measured the refractive indices absorption coefficients of suspensions these nanoparticles using 792nm femtosecond picosecond pulses. The highest values parameters were observed case Au (−8×10−14m2W−1 1.7×10−10mW−1), when 210ps pulses used as a probe radiation. high-order harmonic generation was studied during propagation 120fs through plasmas produced on surfaces containing cutoff (33rd...

Luminescence and related optical properties of Er 3+ Yb -doped YF 3 , Y OC 7 YOCl phosphors are precisely extensively measured in the range from 4.2 K to room temperature, order investigate mechanism controlling factors infrared-to-visible conversion. It is concluded that red luminescence emitted Er: 4 F 9/2 produced by two energy transfers ions, directly populated I 13/2 second transfer. The cutoff phonon electron-phonon coupling constant hosts, which dominate probabilities internal...

Harmonic generation of laser radiation from ionized particles in the extreme ultraviolet range at conditions phase matching between femtosecond driving field and harmonics is an advanced concept for development efficient coherent sources this spectral region. Here we present experimental evidence quasi-phase-matched high-order harmonic multiple plasma jets produced during ablation silver target. We observed both enhancement some groups along plateau variation maximally enhanced order;...

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...

We have demonstrated a generation of the noise-like pulse (NLP) with broadband spectrum in nonlinear polarized evolution-based passive mode-locked Yb-doped fiber (YDF) ring laser. At cavity dispersion near zero, NLP bandwidth up to 131 nm (FWHM) was obtained at central wavelength 1070 output power 136 mW and 80 MHz repetition rate. To our best knowledge, this is broadest among reported YDF lasers. The autocorrelation function contained short (30 fs) long (4.6 ps) components. This coherence...

Studies of the quasi-phase-matched harmonics generated in spatially modulated silver plasma are presented. We analyze influence driving and heating pulse energies on enhancement spectral tuning show those enhanced groups by tilting multislit mask placed front ablated targets. Calculations performed laser-produced plasmas demonstrate joint electrons that appeared during target ablation tunnel ionization quasi-phase-matching conditions plasmas.

The damage in fused silica and ${\mathrm{CaF}}_{2}$ crystals induced by wavelength tunable femtosecond lasers is studied. threshold fluence observed to increase rapidly with laser $\ensuremath{\lambda}$ the region of $250--800\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, while it nearly a constant for $800<\ensuremath{\lambda}<2000\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$. ultrafast electronic excitation also studied pump probe method. reflectivity increases latter half pulse, which supports that...

We present the studies of third- and higher-order nonlinear optical processes in barium titanate (BaTiO3) strontium (SrTiO3) nanoparticles. measured refractive indices absorption coefficients BaTiO3 SrTiO3 nanoparticles dissolved ethylene glycol using 790 nm fs ps pulses. The high-order harmonic generation up to 39th order was achieved nanoparticles-contained plumes when femtosecond radiation propagated through preformed plasma. 1×10−6 4×10−6 efficiencies at plateau region were cases plasmas.

High-order harmonic generation up to the 55th order was achieved using 15 nm and 110 silver nanoparticle-containing plumes, when femtosecond radiation propagated through preformed plasma. These results are compared with high-order harmonics generated from plasma produced on surface of bulk at different delays between subnanosecond prepulse pulse.

We demonstrated the intensity enhancement of a single high-order harmonic at wavelength 37.67 nm using lowly ionized antimony laser-ablation plume. The conversion efficiency this was 2.5x10(-5) and output energy 0.3 muJ. Such an single-harmonic caused by multiphoton resonance with strong radiative transition Sb II ions. cutoff harmonics generated in plasma 86 eV (55(th) harmonic).

The high-order harmonic generation was analyzed by interaction of the femtosecond pulses with laser plasma produced on surfaces various targets. formation accomplished prepulse radiation different pulse duration ($160\phantom{\rule{0.3em}{0ex}}\mathrm{fs}$, $1.5\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$, $210\phantom{\rule{0.3em}{0ex}}\mathrm{ps}$, and $20\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$) low-$Z$ (lithium, boron, carbon), medium-$Z$ (manganese, zinc, nickel), high-$Z$ (silver, barium) We...

Experimentally, we demonstrate, to the best of our knowledge, first observation periodic spectrum changing via soliton explosion in a passively mode-locked fiber laser by nonlinear polarization evolution. Using time stretch capture 7220 consecutive single-shot spectra over 100 μs window real time, explosions appear transition between two different mode-locking states. Simultaneous measurements and pulse energy at three output points cavity show that explosion's dynamics are related residual...