Will: JC: In situ measurement of nonlinear carrier-envelope phase changes in hollow fiber compression

We demonstrate a simple and robust single-shot interferometric technique that allows the in situ measurement of intensity-dependent phase changes experienced by ultrashort laser pulses upon nonlinear propagation. The technique is applied to the characterization of carrier-envelope phase noise in hollow fiber compressors both in the pressure gradient and in the static cell configuration. Measurements performed simultaneously with conventional f-to-2f interferometers before and after compression indicate that the noise emerging in the waveguide adds up arithmetically to the phase noise of the amplifier, thus being strongly correlated to the phase noise of the pulses coupled into the compressor.

http://www.opticsinfobase.org/ol/abstract.cfm?uri=ol-39-8-2302

Zsolt: JC: How to focus an attosecond pulse

Attosecond experiments involving focusing of attosecond light pulses can suffer from a spread of the attosecond radiation both in space and time due to optical aberrations. We present a detailed numerical study of the distortions induced in the most common focusing geometries that make use of parabolic, spherical, toroidal and ellipsoidal mirrors. We deduce the consequences on the pulse duration and possible issues that could arise in applications of attosecond pulses. This should serve as a guideline for setting up attosecond focusing optics.

http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-21-2-2506

Zolt: JC: Laser dressed absorption studies

Two papers will serve the bases:

Lucchini et al. Role of electron wavepacket interference in the optical response of helium atoms, NJP, 15, (2013)
Gallmann et al. Resolving intra-atomic electron dynamics with attosecond transient absorption spectroscopy, Molecular Physics, 111, (2013)

Tobi: DM: report about MPL visit and future plans

http://www.mpl.mpg.de/en/institute/russell-division.html

Thoma: JC: High-order-harmonic generation from dense water microdroplets

http://journals.aps.org/pra/abstract/10.1103/PhysRevA.87.063811

We report on high-order-harmonic generation from micrometer-sized liquid water droplets. In pump-probe experiments, the influence of the time delay onto the emission of harmonic radiation is systematically studied. Phase-matching aspects are observed by controlling the focal position and the intensity of the probe pulse. The spatiotemporal dynamics of the droplet during interaction with intense laser pulses are studied by controlling the intensity of the pump pulse. We find transient phase-matching conditions and the expansion dynamics of the droplet to be of major influence on the harmonic yield.
DOI: http://dx.doi.org/10.1103/PhysRevA.87.063811

Allan: JC: Frequency-resolved optical gating capable of carrier-envelope phase determination

http://www.nature.com/ncomms/2013/131115/ncomms3820/full/ncomms3820.html

Recent progress of the coherent light synthesis technology has brought the generation of single-cycle pulses within our reach. To exploit the full potential of such a single-cycle pulse in any applications, it is highly important to obtain the full information of its electric field. Here we propose a novel pulse characterization scheme, which enables us to determine not only the intensity and phase profiles of ultrashort pulses but also their absolute carrier-envelope phase values. The method is based on a combination of frequency-resolved optical gating and electro-optic sampling, which can be extended to a self-referencing scheme to determine the electric field evolution of few-cycle ultrashort pulses. We have experimentally demonstrated the technique to characterize sub-single-cycle infrared pulses, and numerically studied the capability of the scheme to incorporate a self-referencing technique and to extend the wavelength range to visible region.

Lukas: JC: Femtosecond M2,3-Edge Spectroscopy of Transition-Metal Oxides: Photoinduced Oxidation State Change in a-Fe2O3

Femtosecond M2,3-Edge Spectroscopy of Transition-Metal Oxides: Photoinduced Oxidation State Change in a-Fe2O3

http://pubs.acs.org/doi/abs/10.1021/jz401997d?prevSearch=%255BContrib%253A%2Bstephen%2BLeone%255D&searchHistoryKey=