Probing beyond the laser coherence time in optical clock comparisons

Published: March 30, 2016


David B. Hume, David R. Leibrandt


We develop protocols that circumvent the laser noise limit in optical clock comparisons by synchronous probing of two clocks using phase-locked local oscillators. This allows for probe times longer than the laser coherence time, avoids the Dick effect, and supports Heisenberg-limited scaling of measurement precision. We present a model for such frequency comparisons and develop numerical simulations of the protocol with realistic noise sources. This provides a route to reduce frequency ratio measurement durations by more than an order of magnitude as clock inaccuracies reach 1x10-18.
Citation: Physical Review Letters
Volume: A 93
Pub Type: Journals


atomic clock, optical clock, optical lattice, quantum metrology, trapped ion
Created March 30, 2016, Updated November 10, 2018