Hamburg 2009 – wissenschaftliches Programm

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SYTT: Photonische Terahertz-Technologien fuer Grundlagenforschung und Anwendung

SYTT 2: Photonische Terahertz-Technologien für Grundlagenforschung und Anwendungen II

SYTT 2.1: Hauptvortrag

Dienstag, 3. März 2009, 16:30–17:00, VMP 8 HS

Photonic Terahertz Technology at 10 GV/m Electric Field Amplitudes — •Alexander Sell, Rüdiger Scheu, Alfred Leitenstorfer, and Rupert Huber — University of Konstanz, Universitätsstraße 10, 78464 Konstanz, Germany

Ultrabroadband THz optoelectronics has evolved into a powerful tool providing direct access to low-energy elementary excitations in condensed matter. Currently the quest for new frontiers like photon echo spectroscopy, coherent control and high-harmonics generation, calls for phase stable pulses with enhanced electric field amplitudes. We introduce a novel scheme combining the stability and versatility of a multi-branch Er:fiber seed laser with the high power capabilities of a Ti:sapphire system. In a first approach phase controlled few-cycle THz transients with energies as high as 19 µJ and peak field amplitudes of 108 MV/cm are synthesized by difference frequency mixing (DFM) of two OPAs sharing one seed continuum. Full amplitude and phase information is gained via electro-optic sampling employing 8-fs pulses provided by a numerically optimized nonlinear bulk fiber in the Er:system. In a second approach we demonstrate gating of phase stable pulses with frequency components up to 135 THz and average THz powers of 1.4 mW which are generated by DFM of two branches of the fiber laser. The center frequencies from our hybrid system cover the entire THz spectral range from 1 to 107 THz marking a new record for phase-locked table-top sources. The unprecedented field amplitudes give rise to first observations of extreme THz nonlinearities in condensed matter.