title: Phase-resolved two-dimensional spectroscopy based on collinear n-wave mixing in the ultrafast time domain.
abstract: We present a novel approach for femtosecond two-dimensional (2D) spectroscopy in the midinfrared combining a collinear beam geometry and phase-resolved detection. Two phase-locked pulses of variable time delay tau interact with the sample. The transmitted electric fields are measured in real time t by electro-optic sampling. 2D spectra are generated by Fourier transforming the signal along the two time axes tau and t. In the 2D spectra, nonlinear signals originating from different orders n in the electric field are separated. Such decomposition of the overall response is demonstrated by mapping the nonlinear response of intersubband transitions in GaAs/AlGaAs multiple quantum wells.
authors.affiliation: Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, 12489 Berlin, Germany. wkuehn@mbi-berlin.de
authors.forename: W
authors.initials: W
authors.lastname: Kuehn
authors.forename: K
authors.initials: K
authors.lastname: Reimann
authors.forename: M
authors.initials: M
authors.lastname: Woerner
authors.forename: T
authors.initials: T
authors.lastname: Elsaesser