High-repetition rate tunable laser system for low-noise measurements in nanophotonics

• Subject Area: Condensed Matter Physics
• Term: Funded in 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 450233468

In order to establish new research lines in the area of nanophotonics in the visible and near-infrared part of the spectrum we need a powerful and highly tunable pulsed laser source with a high repetition rate of dozens of MHz. This will enable us to conduct measurements with a low noise level, which is not possible with the current systems available in our ultrafast laboratory. The new light source will be coupled with existing infrastructure available in this lab, particularly an interferometric pulse compression system and a confocal microscope setup, which enables experiments at single nanostructure level. Two particular examples of newly enabled research are in the areas of energy conversion from photons to acoustic surface waves, and in the coupling of single-photon emitters such as nanodiamonds with hybrid nanophotonic resonators. The planned experiments necessitate high average excitation powers, wide tunability over the whole of the visible and near-infrared spectrum, and a high repetition rate, in order to allow measurements with a signal several orders of magnitude above the dark noise level. Additional research fields where we will use the new laser system are in the area of non-linear photonics of hybrid nanostructures, consisting of both plasmonic and dielectric materials as well as 2D structures. The preferred laser system has as distinguishing factors a high average power, broad tunability from 350 to 4000 nm wavelength, and a high flexibility for various pump/probe configurations.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Durchstimmbare Laserquelle mit hoher Repetitionsrate für nanophotonische Messungen mit geringem Rauschen
• Instrumentation Group: 5700 Festkörper-Laser
• Applicant Institution: Ludwig-Maximilians-Universität München
• Leader: Professor Dr. Stefan Maier