Opt Lett. 2015 Mar 1;40(5):823-6. doi: 10.1364/OL.40.000823.
Wunram M, Storz P, Brida D, Leitenstorfer A.
Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
A high-power femtosecond Yb:fiber amplifier operating with exceptional noise performance and long-term stability is demonstrated. It generates a 10-MHz train of 145-fs pulses at 1.03 μm with peak powers above 36 MW. The system features a relative amplitude noise of 1.5·10⁻⁶ Hz(-1/2) at 1 MHz and drifts of the 60-W average power below 0.3% over 72 hours of continuous operation. The passively phase-stable Er:fiber seed system provides ultrabroadband pulses that are synchronized at a repetition rate of 40 MHz. This combination aims at new schemes for sensitive experiments in ultrafast scientific applications.
Advances in metrology, high-precision manipulation of materials and scientific experiments with ultrafast time resolution necessitate laser sources providing superior output characteristics and stability as compared to technology that was previously available. This system combines the excellent noise performance, passive phase stability and ultrabroad bandwidth of femtosecond Er:fiber technology with the benefits of a high-power Yb:fiber amplifier that boosts pulse energies by three orders of magnitude. It will be an unprecedented tool to carry out cutting-edge studies in frontier fields such as nonperturbative nonlinear optics and quantum dynamics of condensed matter as well as sub-cycle quantum physics. We foresee also applications in precision measurements with an ultrastable and high-power femtosecond frequency comb or as an ultralow-noise source for new variants of materials processing based on the electric field trace of a few-cycle laser pulse. The system is passively phase locked and allows the generation of an octave-spanning supercontinuum with a fraction of only 5% of the total output even in bulk focusing geometry. These features enable immediately the next steps of scientific progress.
Visible part of the supercontinuum generated using a small fraction of the total output power of the ultrastable fiber amplifier, as dispersed with a prism onto a white scattering surface.