Third-generation femtosecond technology

Femtosecond pulse generation was pioneered four decades ago using mode-locked dye lasers, which dominated the field for the following 20 years. Dye lasers were then replaced with titanium-doped sapphire (Ti:Sa) lasers, which have had their own two-decade reign. Broadband optical parametric amplifiers (OPAs) appeared on the horizon more than 20 years ago but have been lacking powerful, cost-effective picosecond pump sources for a long time. Diode-pumped ytterbium-doped solid-state lasers are about to change this state of affairs profoundly. They are able to deliver 1 ps scale pulses at kilowatt-scale average power levels, which, in thin-disk lasers, may come in combination with terawatt-scale peak powers. Broadband OPAs pumped by these sources hold promise for surpassing the performance of current femtosecond systems so dramatically as to justify referring to them as the next generation. Third-generation femtosecond technology (3FST) offers the potential for femtosecond light tunable over several octaves, multi-terawatt few-cycle pulses, and synthesized multi-octave light transients. Unique tunability, temporal confinement, and waveform variety in combination with unprecedented average powers will extend nonlinear optics and laser spectroscopy to previously inaccessible wavelength domains, ranging from the far IR to the x-ray regime. Here we review the underlying concepts, technologies, and proof-of-principle experiments. A conceptual design study of a prototypical tunable and wideband source demonstrates the potential of 3FST for pushing the frontiers of femtosecond and attosecond science. (C) 2014 Optical Society of America11138sciescopu

Pre-excitation studies for rubidium-plasma generation

The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (AWAKE) project is the generation of highly uniform plasma from Rubidium vapor. The standard way to achieve full ionization is to use high power laser which can assure the over-barrier-ionization (OBI) along the 10 meters long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi Photon Ionization (REMPI) scheme probably can be realized by much less laser power. In the following the resonant pre-excitations of the Rb atoms are investigated, theoretically and the status report about the preparatory work on the experiment are presented

Pre-excitation studies for rubidium-plasma generation

a b s t r a c t The key element in the Proton-Driven-Plasma-Wake-Field-Accelerator (PWFA) project is the generation of highly uniform plasma from Rubidium vapor. A scientifically straightforward, yet highly challenging way to achieve full ionization is to use high power laser which can assure the barrier suppression ionization (BSI) along the 10 m long active region. The Wigner-team in Budapest is investigating an alternative way of uniform plasma generation. The proposed Resonance Enhanced Multi-Photon Ionization (REMPI) scheme can be probably realized by much less laser power. In the following we plan to investigate the resonant pre-excitations of the Rb atoms, both theoretically and experimentally. In the following our theoretical framework is presented together with the status report about the preparatory work of the planned experiment

Supplement 1: Third-generation femtosecond technology

Originally published in Optica on 22 July 2014 (optica-1-1-45