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Soft x-ray spectra generated on flat Al targets by a 500 fs KrF* laser pulse (intensity 5.3×1015 W/cm2), preceded by a prepulse of the same pulse duration, have been measured as a function of the pulse separation and the prepulse intensity. It was found that not only the total x-ray emission was much stronger when the prepulse was present but, in particular, lines in the shorter wavelength region had a higher intensity than without prepulse, and were strongly dependent on the time separation between the prepulse and the main pulse.

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Atomic memories for flying photonic qubits are an essential ingredient for many applications like e.g. quantum repeaters. Verification of the coherent transfer of information from a light field to an atomic superposition is usually obtained using an optical read-out. In this paper we report the direct detection of the atomic coherence by means of atom interferometry. We experimentally verified both that a bichromatic laser field closing a Raman transition imprints a distinct, controllable phase on the atomic coherence and that it can be recovered after a variable time delay.

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In order to allow widespread application of soft X-ray lasers there is a strong effort worldwide to use as small as possible pump lasers for plasma production. Short pulse lasers (-c~ 1 ps), particularly in the UV, have attracted much interest, since extremely high intensities (up to 10 ~8 W/cm 2) can be achieved with a relatively high repetition rate. In this article we discuss their merit for soft X-ray laser pumping and possible solutions to the specific problems, for instance pulse front distortion, nonlinear absorption in window materials, plasma formation by short laser pulses and the relatively low total pump energy.

Matter-wave interferometry is a powerful tool for high-precision measurements of the quantum properties of atoms, many-body phenomena and gravity. The most precise matter-wave interferometers exploit the excellent localization in momentum space and coherence of the degenerate gases. Further enhancement of the sensitivity and reduction of complexity are crucial conditions for the success and widening of their applications. Here we introduce a multistate interferometric scheme that offers advances in both these aspects. The coherent coupling between Bose-Einstein condensates in different Zeeman states is used to generate high-harmonic output signals with an enhanced resolution and the maximum possible interferometric visibility. We demonstrate the realization of such an interferometer as a compact, easy to use, atomchip device. This provides an alternative method for the measurement of the light-atom and surface-atom interactions and enables the application of multiparameter sensing schemes in cold-atom interferometry.

The possibility of obtaining laser action from Mn z+ doped glass has been investigated. The excited state absorption at the expected laser wavelength was measured and explains the unsuccessful attempts to obtain laser action.