CEP stabilized high power ultrashort pulse laser system

• Subject Area: Condensed Matter Physics
• Term: Funded in 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 506452342

Ultra-short pulse lasers with pulse durations in the range of 100 fs are now established in many research laboratories and have become indispensable tools. However, only extremely short pulse durations of less than 10 fs allow the time-resolved analysis of atomic or molecular processes such as chemical reactions or thermalization processes or to influence them in a selective manner.This opens up numerous possibilities to study and control the interaction of ultrashort light pulses with nanostructures, molecules and even individual atoms. However, for these so-called few cycle pulses, a description of the pulses based only on the envelope is no longer sufficient. Instead, the electric field and the absolute phase (so-called carrier envelope phase - CEP) are crucial for the light-matter interaction.For this reason, a carrier envelope phase (CEP)-stabilized ultrashort pulse laser system will be installed at the Abbe Center of Photonics in Jena, providing both high pulse energies and high average powers as well as the possibility of temporal and spectral pulse shaping. The system will enable several research groups to perform different investigations and applications. In particular, the following topics will be addressed:1. Investigations on the influence of CEP and spectral as well as temporal pulse properties on photoinduced tunneling effects, ultrafast switching and nonlinear optical effects (such as efficient frequency conversion) in large area resonant nanostructures. This requires phase-stabilized light pulses in the NIR (about 800 nm) with a pulse length smaller than 10 fs. The repetition rate must be adjustable from single shot to at least 50 kHz to distinguish between slow thermal and fast electronic effects.2. The CEP stabilized, temporally and spectrally shaped pulses shall be used to control chemical reactions in gases and photocatalytic systems. In the laser system an additional probe pulse is generated that allows the temporally and spatially resolved quantitative analysis of reaction products by CARS-spectroscopy (CARS – coherent Anti-Stokes Raman Scattering). The detection of all possible intermediates requires a spectral width of the pump pulse greater than 4200 cm-1. The temporally synchronized probe pulse at a significant shorter wavelength (515 nm) has a spectral width smaller than 10 cm-1, which defines the spectral resolution of the measurement.3. In 2D-materials fundamental research on spatio-temporal dynamics of free charge carriers by means of pump-probe experiments shall be performed. Typical thermalization times of these systems are in the range of the pulse duration of the applied system (ca. 10fs). By varying the CEP, the correlation of the geometric symmetry of the structures with the temporal symmetry of the pulse will be investigated.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: CEP-stabilisiertes Hochleistungs-Ultrakurzpuls-Lasersystem
• Instrumentation Group: 5700 Festkörper-Laser
• Applicant Institution: Friedrich-Schiller-Universität Jena
• Leader: Professor Dr. Stefan Nolte