K Predehl

Learn More
Optical clocks show unprecedented accuracy, surpassing that of previously available clock systems by more than one order of magnitude. Precise intercomparisons will enable a variety of experiments, including tests of fundamental quantum physics and cosmology and applications in geodesy and navigation. Well-established, satellite-based techniques for(More)
We propose and experimentally demonstrate a method for generating and sharing a secret key using phase fluctuations in fiber optical links. The obtained key can be readily used to support secure communication between the parties. The security of our approach is based on a fundamental asymmetry associated with the optical physical layer: the sophistication(More)
We demonstrate a fully optical, remote characterization of independent ultrastable lasers separated by a geographical distance of more than 50 km via a 73 km long phase-stabilized fiber in a commercial telecom-munication network. The phase-coherent comparison shows a fractional frequency instability between the independent ultrastable laser systems of σy =(More)
  • 1