Bülend Ortaç, Friedrich-Schiller-University Jena, Germany
High-energy ultra-short pulse fiber lasers
High-energy and high-average-power femtosecond lasers are interesting for many applications, including scientific instrumentation, industrial material processing, imaging, medical and military technologies. In contrast with other solid-state lasers, rare-earth-doped fibers are well-suited for ultrafast applications from picosecond range to femtosecond. Mode-locked fiber lasers offer a number of advantages as they have a large amplification bandwidth supporting ultrashort pulses, exhibit improved stability, freedom from misalignment and diffraction limited beam. In addition, they offer compact design with inexpensive components and are suitable for high-average-power applications because their geometry leads to efficient heat dissipation. In this seminar, we will show the generation of picosecond or femtosecond pulses from different kind of the fiber laser concepts. However, depending on the experimental set-up, these lasers can operate in very different regimes that can be detrimental for some applications. These fiber sources can generate pulses with output energies from some tens of picojoules to some tens of nanojoules, duration from 100 fs to picosecond range at repetition rate from few tens of MHz to GHz. Within this seminar, different cavity designs (ring, linear and sigma) and different mode-locking regimes (soliton, stretched and wave-breaking free) will be also discussed.