Alternate Approach to Ramsey-Bordé Interferometry for Atom Spectroscopy

Ramsey-Bordé interferometers enable high-precision measurements of atomic resonance frequencies, but suffer from contrast loss due to stray atom paths. We propose an alternate pulse sequence that retains the same sensitivity of Ramsey-Bordé interferometers to atom-laser detuning, but achieves higher contrast by mitigating loss from stray paths. This method is applied to precision measurements of the intercombination line of Sr-88 using a free-fall interferometer operating on single-photon transitions.