Study of Raman-Ramsey fringes for enhanced precision in a chip scale Rb clock

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 phasescanned Raman-Ramsey fringes, with potential application to sensitive detection of trace vapors.