Bernhard Mayer

Learn More
Understanding the effects of climate change including precipitation patterns has important implications for evaluating the biogeochemical responses of watersheds. We focused on four storms in late summer and early fall that occurred after an exceptionally dry period in 2002.We analyzed not only the influence of these storms on episodic chemistry and the(More)
We generate sub-four-cycle pulses (41.6 fs) with 12 μJ of pulse energy in the mid-infrared spectral range (center wavelength 3.4 μm) from a high-repetition-rate, collinear three-stage optical parametric chirped-pulse amplifier (OPCPA) operating at 50 kHz. Apodized aperiodically poled MgO:LiNbO3 crystals with a negative chirp rate are employed as gain media(More)
We performed batch dissolution experiments on different sized granite and biotite in pure water, in order to better understand the source and geochemical behavior of fluoride in groundwater. Very high concentrations of fluoride (up to 6–10 mg/l) were observed from granite leaching. Correlations between leached ions suggest that fluoride possibly originates(More)
We report the breakdown of the electric dipole approximation in the long-wavelength limit in strong-field ionization with linearly polarized few-cycle mid-infrared laser pulses at intensities on the order of 10¹³ W/cm². Photoelectron momentum distributions were recorded by velocity map imaging and projected onto the beam propagation axis. We observe an(More)
B. Mayer,1 C. Schmidt,1 A. Grupp,1 J. Bühler,1 J. Oelmann,1 R. E. Marvel,2 R. F. Haglund, Jr.,2 T. Oka,3 D. Brida,1 A. Leitenstorfer,1,* and A. Pashkin1,† 1Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany 2Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA(More)
We present an ultra-broadband optical parametric chirped-pulse amplification (OPCPA) system operating at 3.4 µm center wavelength with a peak power of 75 MW. The OPCPA system is split into a pre- and a power-amplifier stage. Both stages are based on apodized aperiodically poled MgO:LiNbO3 (APPLN). The collinear mixing configuration allows us to manipulate(More)
Advances in the amplification and manipulation of ultrashort laser pulses have led to revolutions in several areas. Examples include chirped pulse amplification for generating high peak-power lasers, power-scalable amplification techniques, pulse shaping via modulation of spatially-dispersed laser pulses, and efficient frequency-mixing in(More)
We demonstrate a new regime for mid-infrared optical parametric chirped- pulse amplification (OPCPA) based on achromatic quasi-phase-matching. Our mid-infrared OPCPA system is based on collinear aperiodically poled lithium niobate (APPLN) pre-amplifiers and a non-collinear PPLN power amplifier which is operated in an achromatic phase-matching configuration.(More)
We demonstrate sub-cycle manipulation of mid-infrared optical waveforms in the time domain. This goal is accomplished via efficient reflection at a semiconductor surface induced by femtosecond interband excitation. The ultrafast response of this process allows slicing of high-field multi-terahertz transients down to the single optical cycle. Ultrabroadband(More)
We present recent advances in the generation of highly intense multiterahertz transients and their application to nonlinear spectroscopy of bulk semiconductors. An optimized scheme of parametric amplification results in broadband singleor few-cycle terahertz transients with peak electric fields up to 10 or 2S MV/cm, respectively. Time-resolved four-wave(More)