Henning Geiseler

High-energy half-cycle cutoffs in high harmonic and rescattered electron spectra using waveform-controlled few-cycle infrared pulses

We developed a few-cycle waveform-controlled light source for infrared pulses at that is based on optical chirped-pulse amplification in (BIBO) crystals pumped by Ti:sapphire lasers. Using this source, we observe soft x-ray high harmonics that extend up to a photon energy of , as well as high-energy photoelectrons up to . The spectra of the high harmonics and photoelectrons have clear signatures of half-cycle cutoffs that can be used to extract electronic and molecular dynamics on an attosecond time scale.

Carrier-Envelope Phase Mapping in Laser-Induced Electron Rescattering

We demonstrate the use of the carrier-envelope phase of few-cycle pulses for laser-induced electron diffraction. The phase serves to tune the rescattering energy, which enables a sensitive measurement of differential scattering cross sections.