Quantum Optics Seminar by Uwe Sterr

Ultrastable Lasers – Applications and Challenges

Lasers with long coherence times and narrow bandwidth are an essential tool for precision measurements, like quantum sensors and optical clocks. At present, most of these systems obtain their stability from Fabry-Perot reference cavities, thus relating the fractional frequency instability to fractional length fluctuations of the cavity, with the best systems now achieving instabilities down to 4×10^-17. However, as macroscopic devices these cavities are susceptible to many perturbing influences and, ultimately, limited by fundamental thermodynamic fluctuations.

In my talk I will present the current state of the art, address ways to further reduce the thermal noise, like novel coatings, and discuss applications for optical clocks and timekeeping.