Demonstration of Raman–Ramsey fringes using time delayed optical pulses in rubidium vapor

We report observation of high contrast Raman–Ramsey fringes using time delayed optical pulse pairs in a rubidium vapor cell. The width of these fringes are not limited by saturation and provides a simpler means to produce narrow atomic linewidths using a thermal vapor medium for compact atomic clock applications. We also demonstrate phase-scanned Raman–Ramsey fringes, with potential application to sensitive detection of trace vapors.