The Genuine Article Number: XB494
Weinkauf R., Lehr L., Georgiev D., Schlag EW .
TIME MULTIPLEXING - A NEW SINGLE SHOT FEMTOSECOND PUMP-PROBE
Applied Physics B-Lasers & Optics. 64(5):515-519, 1997 May.
Mass-spectrometry. Laser-pulses. Spectroscopy. Molecules. Phase.
Dissociation. Transition. Dynamics.
We propose a new multiplex and fast readout technique for gaining a
complete femtosecond pump-probe spectrum in a single shot which can be
monitored on a conventional oscilloscope. The technique is based on
counterpropagating fs laser pulses in gaseous samples of low density and
probe detection by ion or fragment ion formation. Along the laser interaction
path, each site in the sample corresponds to a particular pump-probe delay:
The complete molecular response is multiplexed to a one dimensional spatial
map of ion density. We propose a time-of-flight mass spectrometer for the fast
point-wise readout e.g. the demultiplexing of this ion map. By calculation and
experiments we find that a linear demultiplexing is possible and that in a
reflectron time-of-flight instrument a 100 fs pump-probe delay interval
translates to an easily resolved time-of-flight spacing of 10 ns. The range of
pump-probe delays that is estimated to be accommodated covers 100 fs up to
10 ps. The technique is combined with mass selection providing mass
resolution of 100. [References: 32]
Applied physics/condensed matter/materials science.
Current Contents/Physical, Chemical & Earth Sciences
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INST PHYSICAL CHEMISTRY & ELECTROCHEMISTRY I