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Picosecond

About: Picosecond is a research topic. Over the lifetime, 11935 publications have been published within this topic receiving 213764 citations. The topic is also known as: ps.


Papers
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Journal ArticleDOI
TL;DR: Theoretical models and qualitative explanations of experimental results are presented in this paper for femtosecond laser ablation of solid targets by 0.2-5000 ps Ti: Sapphire laser pulses.
Abstract: Laser ablation of solid targets by 0.2–5000 ps Ti: Sapphire laser pulses is studied. Theoretical models and qualitative explanations of experimental results are presented. Advantages of femtosecond lasers for precise material processing are discussed and demonstrated.

2,513 citations

Journal ArticleDOI
TL;DR: The relaxation processes of electrons and spins systems following the absorption of femtosecondoptical pulses in ferromagnetic nickel have been studied using optical and magneto-optical pump-probetechniques and the experimental results are adequately described by a model including three interacting reservoirs.
Abstract: The relaxation processes of electrons and spins systems following the absorption of femtosecond optical pulses in ferromagnetic nickel have been studied using optical and magneto-optical pump-probe techniques. The magnetization of the film drops rapidly during the first picosecond, but different electron and spin dynamics are observed for delays in the range 0--5 ps. The experimental results are adequately described by a model including three interacting reservoirs (electron, spin, and lattice).

1,920 citations

Journal ArticleDOI
TL;DR: In this article, a supercurrent-assisted hotspot-formation mechanism for ultrafast detection and counting of visible and infrared photons is presented, where a photon-induced hotspot leads to a temporary formation of a resistive barrier across the superconducting sensor strip and results in an easily measurable voltage pulse.
Abstract: We experimentally demonstrate a supercurrent-assisted, hotspot-formation mechanism for ultrafast detection and counting of visible and infrared photons. A photon-induced hotspot leads to a temporary formation of a resistive barrier across the superconducting sensor strip and results in an easily measurable voltage pulse. Subsequent hotspot healing in ∼30 ps time frame, restores the superconductivity (zero-voltage state), and the detector is ready to register another photon. Our device consists of an ultrathin, very narrow NbN strip, maintained at 4.2 K and current-biased close to the critical current. It exhibits an experimentally measured quantum efficiency of ∼20% for 0.81 μm wavelength photons and negligible dark counts.

1,529 citations

Journal ArticleDOI
TL;DR: In this article, a detailed theoretical treatment of different excitation and probing processes are outlined and a variety of results are presented and discussed, including the population lifetime of known vibrational modes and evidence for inter-and intra-molecular interactions.
Abstract: With well-defined coherent light pulses of several ${10}^{\ensuremath{-}12}$ sec duration we are in a position to investigate a variety of ultrafast vibrational processes in liquids and solids. Several new experimental techniques have been devised to study directly the dynamics of different vibrational modes and molecules in the electronic ground state. A first light pulse excites the vibrational system via stimulated Raman scattering or by resonant infrared absorption. A second interrogating pulse allows one to determine the instantaneous state of the excited system. Using a coherent probing technique one can measure the dephasing time of homogeneously broadened vibrational transitions and a collective beating of multiple isotope levels. In addition, one can investigate inhomogeneously broadened vibrational modes and observe the dephasing time of a small molecular subgroup. Different information is obtained when the coherent anti-Stokes Raman scattering of the probe pulse is measured. The population lifetime of known vibrational modes can be investigated and evidence for inter- and intra-molecular interactions is obtained. In a third probing technique, the vibrationally excited jolecules are promoted to the first electronic state by a second pulse and the fluorescence is measured. In this way it is possible to see the very rapid change of population of the primary excited vibrational mode. The article gives a detailed theoretical treatment of different excitation and probing processes. Several experimental techniques successfully applied in the authors investigations are outlined and a variety of results is presented and discussed. New information, not available from other experimental methods, is obtained.

870 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023354
2022782
2021199
2020279
2019257
2018250