Abstract

Optical parametric amplifiers (OPAs) with broadband spectra in the near- to mid-infrared have become an attractive light source for investigating strong-field effects [1]. In order to characterize the generated infrared pulses, one needs to temporarily resolve their electric field. Since its first applications more than twenty years ago [2,3], electro-optic sampling (EOS) has proven a powerful technique for unambiguously recording THz transients and phase-stable mid-infrared pulses up to a cutoff frequency of about 120THz [4]. Compared to other complete characterization techniques like attosecond streaking [5], EOS neither requires the generation of synchronized XUV pulses and thus an experimental setup in vacuum, nor complicated post-processing. By using a sub-two-cycle whitelight probe pulse and a thin BBO crystal for broadband phasematching, we show that EOS can be used to characterize a phase-stable, almost octave-spanning OPA [6] with frequencies up to 200 THz.

© 2015 IEEE