Topic
Femtosecond
About: Femtosecond is a research topic. Over the lifetime, 35106 publications have been published within this topic receiving 691405 citations. The topic is also known as: 1 E-15 s & fs.
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TL;DR: In this article, a simple and easily-controlled method for fabricating stainless steel-based superhydrophobic surfaces is presented, which consists of microstructuring stainless steel surfaces by irradiating samples with femtosecond laser pulses and silanizing the surfaces.
356 citations
TL;DR: A directional coupler written in a glass sample by the focused 400-nm output from a 25-fs oscillator is reported; the coupler is single mode; the splitting ratio is 1.9 dB at 633 nm.
Abstract: A directional coupler written in a glass sample by the focused 400-nm output from a 25-fs oscillator is reported. The coupler is single mode; the splitting ratio is 1.9 dB at 633 nm. A refractive-index profile of the waveguide with a magnitude of Δn=4.5×10-3 was retrieved from a near-field mode pattern.
356 citations
351 citations
TL;DR: Femtosecond transient absorption measurements of the photoisomerization of azobenzene excited at 435 nm in the long-wavelength formation with a dominating 170 fs and a weak 2 ps component are found.
350 citations
TL;DR: The rapidly decreasing microscopic single-atom yield, predicted for harmonics driven by longer-wavelength lasers, is compensated macroscopically by an increased optimal pressure for phase matching and a rapidly decreasing reabsorption of the generated X-rays, making tabletop, fully coherent, multi-keV X-ray sources feasible.
Abstract: We show how bright, tabletop, fully coherent hard X-ray beams can be generated through nonlinear upconversion of femtosecond laser light. By driving the high-order harmonic generation process using longer-wavelength midinfrared light, we show that, in theory, fully phase-matched frequency upconversion can extend into the hard X-ray region of the spectrum. We verify our scaling predictions experimentally by demonstrating phase matching in the soft X-ray region of the spectrum around 330 eV, using ultrafast driving laser pulses at 1.3-μm wavelength, in an extended, high-pressure, weakly ionized gas medium. We also show through calculations that scaling of the overall conversion efficiency is surprisingly favorable as the wavelength of the driving laser is increased, making tabletop, fully coherent, multi-keV X-ray sources feasible. The rapidly decreasing microscopic single-atom yield, predicted for harmonics driven by longer-wavelength lasers, is compensated macroscopically by an increased optimal pressure for phase matching and a rapidly decreasing reabsorption of the generated X-rays.
347 citations