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Warntjes JB Gürtler A Osterwalder A Rosca-Pruna F Vrakking MJ Noordam LD 《Optics letters》2001,26(19):1463-1465
A novel method of detecting the spectral width and wavelength of extreme ultraviolet (XUV) pulses with a minimum number of experimental tools is demonstrated. The method relies on the photoionization probability of an atom as a function of the electric field. A tunable laser source in the XUV is used that is based on higher-harmonic generation of the frequency-doubled output of a 50-fs Ti:sapphire laser. The bandwidth and the wavelength of the seventh harmonic (~57nm) are detected with Ne, and the resolving power is lambda/Dlambda=10(5). 相似文献
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We present a quantum theory for the interaction of a quantum target with a time dependent matter beam. When several pulses in the incident beam arrive with a period tau, transitions between levels with an energy difference h/tau can be enhanced. Unlike all previous studies, we find that transitions in passive targets can distinguish between an incoherent beam and a beam with a coherent wave packet structure. As an example, we calculate the transition probability of Rb Rydberg atoms interacting with a pulsed electron beam. 相似文献
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A THz "half-cycle" pulse is a fast ( <1 ps) unipolar pulse, followed by a slow unipolar pulse of opposite polarity. We found that the interaction of such THz pulses with very high Rydberg states results in a displacement of the electron within the atom, while the ionization is strongly suppressed. In classical terms: the first fast unipolar feature corresponds to a start kick of the Rydberg electron, while the second unipolar feature acts as a stop kick. A semiclassical model is presented which qualitatively reproduces the ionization suppression and redistribution. 相似文献
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C. S.E.?van DitzhuijzenEmail author A. F.?Koenderink L. D.?Noordam H.B.?van Linden van den Heuvell 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2006,40(1):13-17
We present a technique for state-selective position
detection of cold Rydberg atoms. Ground state Rb atoms in a
magneto-optical trap are excited to a Rydberg state and are
subsequently ionized with a tailored electric field pulse. This
pulse selectively ionizes only atoms in e.g. the 54d state and not
in the 53d state. The released electrons are detected after a slow
flight towards a micro channel plate. From the time of flight of
the electrons the position of the atoms is deduced. The state
selectivity is about 20:1 when comparing 54d with 53d and the
one-dimensional position resolution ranges from 6 to 40 μm
over a range of 300 μm. This state selectivity and position
resolution are sufficient to allow for the observation of coherent
quantum excitation transport. 相似文献