88 research outputs found
Phase-matched extreme-ultraviolet frequency-comb generation
Laser-driven high-order harmonic generation (HHG) provides tabletop sources
of broadband extreme-ultraviolet (XUV) light with excellent spatial and
temporal coherence. These sources are typically operated at low repetition
rates, 100 kHz, where phase-matched frequency conversion into
the XUV is readily achieved. However, there are many applications that demand
the improved counting statistics or frequency-comb precision afforded by
operation at high repetition rates, > 10 MHz. Unfortunately, at such
high , phase matching is prevented by the accumulated steady-state
plasma in the generation volume, setting stringent limitations on the XUV
average power. Here, we use gas mixtures at high temperatures as the generation
medium to increase the translational velocity of the gas, thereby reducing the
steady-state plasma in the laser focus. This allows phase-matched XUV emission
inside a femtosecond enhancement cavity at a repetition rate of 77 MHz,
enabling a record generated power of 2 mW in a single harmonic order.
This power scaling opens up many demanding applications, including XUV
frequency-comb spectroscopy of few-electron atoms and ions for precision tests
of fundamental physical laws and constants.Comment: 9 pages, 4 figure
Noncollinear enhancement cavity for record-high out-coupling efficiency of an extreme-UV frequency comb
We demonstrate a femtosecond enhancement cavity with a crossed-beam geometry
for efficient generation and extraction of extreme-ultraviolet (XUV) frequency
combs at a 154 MHz repetition rate. We achieve a record-high out-coupled power
of 600 {\mu}W, directly usable for spectroscopy, at a wavelength of 97 nm. This
corresponds to a >60% out-coupling efficiency. The XUV power scaling and
generation efficiency are similar to that achieved with a single Gaussian-mode
fundamental beam inside a collinear enhancement cavity. The noncollinear
geometry also opens the door for the generation of isolated attosecond pulses
at >100 MHz repetition rate.Comment: 13 pages, 5 figure
Self-broadening and self-shift in the band of ammonia from mid-infrared-frequency-comb spectroscopy
We report the broadband absorption spectrum of the band of
NH near 4 . The data were recorded using a mid-infrared
frequency comb coupled to a homebuilt Fourier-transform spectrometer with a
resolution of 0.00501 . Line positions, line intensities,
self-broadening, and self-shift parameters for six rovibrational lines were
determined at room temperature ( K). Comparison with HITRAN 2016 shows
good agreement at improved precision. The high precision and the rapid
tunability of our experiment enables advanced fast spectroscopy of molecular
gases
Dispersion-engineered multi-pass cell for single-stage post-compression of an ytterbium laser
Post-compression methods for ultrafast laser pulses typically face challenging limitations, including saturation effects and temporal pulse breakup, when large compression factors and broad bandwidths are targeted. To overcome these limitations, we exploit direct dispersion control in a gas-filled multi-pass cell, enabling, for the first time to the best of our knowledge, single-stage post-compression of 150 fs pulses and up to 250 µJ pulse energy from an ytterbium (Yb) fiber laser down to sub-20 fs. Dispersion-engineered dielectric cavity mirrors are used to achieve nonlinear spectral broadening dominated by self-phase modulation over large compression factors and bandwidths at 98% throughput. Our method opens a route toward single-stage post-compression of Yb lasers into the few-cycle regime
A dispersion-engineered multi-pass cell for single-stage post compression of an Ytterbium laser
Post-compression methods for ultrafast laser pulses typically face
challenging limitations including saturation effects and temporal pulse
break-up when large compression factors and broad bandwidths are targeted. To
overcome these limitations, we exploit direct dispersion control in a
gas-filled multi-pass cell, enabling for the first time single-stage
post-compression of 150 fs pulses and up to 250 uJ pulse energy from an
Ytterbium (Yb) fiber laser down to sub-20 fs. Dispersion-engineered dielectric
cavity mirrors are used to achieve nonlinear spectral broadening dominated by
self-phase-modulation over large compression factors and bandwidths at 98%
throughput. Our method opens a route towards single-stage post-compression of
Yb lasers into the few-cycle regime
Carrier-envelope phase dependent high-order harmonic generation with a high-repetition rate OPCPA-system
We study high-order harmonic generation with a high-repetition rate (200 kHz), few-cycle, driving laser, based on optical parametric chirped pulse amplification. The system delivers carrier-envelope phase stable, 8 fs, 10 μJ pulses at a central wavelength of 890 nm. High-order harmonics, generated in a high-pressure Ar gas jet, exhibit a strong CEP-dependence over a large spectral range owing to excellent stability of the driving laser pulses. This range can be divided into three spectral regions with distinct CEP influence. The observed spectral interference structures are explained by an analytical model based upon multiple pulse interferences.Marie Curie Research Training Network ATTOFELEuropean Research CouncilKnut and Alice Wallenberg foundationSwedish Foundation for Strategic ResearchSwedish Research Counci
Roadmap on ultrafast optics
Contains fulltext :
166150.pdf (publisher's version ) (Closed access
Acousto-Optic Modulation in Ambient Air
Control over intensity, shape, direction and phase of coherent light is a
cornerstone of 20 photonics. Modern laser optics, however, frequently demands
parameter regimes where either the wavelength or the optical power restricts
control e.g. due to absorption or damage. Limitations are imposed by the
properties of solid media, upon which most photonic control schemes rely. We
propose to circumvent these limitations using gas media tailored by
high-intensity ultrasound waves. We demonstrate a first implementation of this
approach by modulating ultrashort laser 25 pulses using ultrasound waves in
ambient air, entirely omitting transmissive solid media. At peak powers of 20
GW exceeding the limits of solid-based acousto-optical modulation by about
three orders of magnitude, we reach a diffraction efficiency greater than 50%
while preserving excellent beam quality. Our results open a route towards
versatile gas-phase Sono-Photonic methods, i.e. gas-based photonic systems
controlled by sonic waves.Comment: 20 pages, including 11 pages of main text and 9 pages of
supplementary text, 3 figures, 3 supplemtary figures, 1 supplementary tabl
Scientific Opportunities with an X-ray Free-Electron Laser Oscillator
An X-ray free-electron laser oscillator (XFELO) is a new type of hard X-ray
source that would produce fully coherent pulses with meV bandwidth and stable
intensity. The XFELO complements existing sources based on self-amplified
spontaneous emission (SASE) from high-gain X-ray free-electron lasers (XFEL)
that produce ultra-short pulses with broad-band chaotic spectra. This report is
based on discussions of scientific opportunities enabled by an XFELO during a
workshop held at SLAC on June 29 - July 1, 2016Comment: 21 pages, 12 figure
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