Project Details
Projekt
RABBITT with tailored fields: Measuring dipole transitions in the continuum
Applicant
Dr. Anne Harth
Subject Area
Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
Term
from 2018 to 2023
Project identifier
Deutsche Forschungsgemeinschaft (DFG) - Project number 411044455
Attosecond pulses allow the observation of attosecond dynamics of electron motion in a variety of different systems. One method to measure such ultrafast dynamics is based on the reconstruction of attosecond beating by the interference of two-photon transitions (also called RABBITT). As the name suggests, the RABBITT method is based on two-photon transition steps: a train of attosecond pulses ionizes the system, this is the first photo absorption step, and a weak probe field drives a continuum-continuum dipole transition. In this project we propose an experiment, based on an extended RABBITT technique, promising to gain general information about dipole transitions in the continuum. The main idea is to compare two RABBITT measurements, where the ionization step is the same for both measurements, but e.g. the number of continuum-continuum transitions differ. This can be realized choosing a smaller probe frequency.When e.g. the attosecond pulse train is generated by a driving laser with a frequency of 2ω, the standard RABBITT method uses the same frequency 2ω as probe beam. But if the half frequency ω will be used, two continuum-continuum transitions are involved. This multi-color Rabbit method is easily extendable generating the attosecond pulse train e.g. with the third harmonic and probe the system with the third or second or fundamental field. It will be also possible to probe with a multi-color field, when e.g. the second and fundamental fields are mixed. These tailored fields can be further manipulated by changing the phase or the polarization of one of the fields. The knowledge gained with the multi-color RABBITT technique is important for the correct interpretation of experiments dealing with attosecond dynamics close to the ionization threshold.
DFG Programme
Priority Programmes
Co-Investigators
Privatdozent Dr. Robert Moshammer; Professor Dr. Thomas Pfeifer
