A New Generation of Ultrafast Oscillators for Mid-Infrared Applications

This thesis presents the first successful realization of a compact, low-noise, and few-cycle light source in the mid-infrared wavelength region. By developing the technology of pumping femtosecond chromium-doped II-VI laser oscillators directly with the emission of broad-stripe single-emitter laser diodes, coherent light was generated with exceptionally low amplitude noise - crucial for numerous applications including spectroscopy at high sensitivities. Other key parameters of the oscillator's output, such as pulse duration and output power, matched and even surpassed previous state-of-the-art systems. As a demonstration of its unique capabilities, the oscillator's powerful output was used to drive - without further amplification - the nonlinear generation of coherent mid-infrared light spanning multiple octaves. The resulting table-top system uniquely combines high brilliance and ultrabroad spectral bandwidth in the important mid-infrared spectral range. The rapiddevelopment of this technology is comprehensively and lucidly documented in this PhD thesis. Together with a thorough review of literature and applications, and an extensive analysis of the theoretical foundations behind ultrafast laser oscillators, the thesis will serve as a valuable reference for the construction of a new generation of mid-infrared light sources.

Auteur
Nathalie Nagl was born in Landshut, Germany, in 1994. She studied Physics at the Ludwig-Maximilians-Universität München, Germany, from where she received her M.Sc. degree in 2017. From 2018 to 2021, she conducted her PhD work at the Laboratory for Attosecond Physics in Garching, Germany, under the supervision of Prof. Dr. Ferenc Krausz and received her Ph.D. in Physics in January 2021. Since then, she has been working as a postdoctoral researcher at the Max Planck Institute of Quantum Optics, where she continues to push the frontiers of high-repetition-rate femtosecond laser sources and aims to generate highly-intense few-cycle pulses at exotic wavelengths in the mid-infrared spectral region.

Contenu
Motivation.- FUNDAMENTALS of Ultrashort Pulse Generation.- THE FIRST Directly Diode-Pumped Few-Cycle Cr-Doped II-VI Laser.- REACHING THE PERFORMANCE of the State of the Art.- Pushing the PEAK POWER for Direct Mid-Infrared Generation.- CONCLUSION and OUTLOOK.- APPENDIX.