Ramsey-Borde Matter-Wave Interferometry for Laser Frequency Stabilization at 10-16 Frequency Instability and Below
Judith B. Olson, Todd Sheerin, Holly Leopardi, Roger C. Brown, Richard W. Fox, Rick Stoner, Tara M. Fortier, Christopher W. Oates, Andrew D. Ludlow
We demonstrate Ramsey-Borde (RB) atom interferometry for high performance laser stabilization with fractional frequency instability −16 for timescales between 10 and 1000s. The RB spectroscopy laser interrogates two counterpropagating 40Ca beams on the 1S0 - 3 P1 transition at 657 nm, yielding 1.6 kHz linewidth interference fringes. Fluorescence detection of the excited state population is performed on the (4s4p) 3P1 − (4p2) 3P0 transition at 431 nm. Minimal thermal shielding and no vibration isolation are used. These stability results surpass performance from other thermal atomic or molecular systems by 1 to 2 orders of magnitude, and further improvements look feasible.