Towards a Raman-Ramsey Clock based on a Cold Cesium Beam

The continuous cold atomic clocks have the potential to overcome the Dick effect and to develop compact devices. In this paper, we present a process towards a Raman-Ramsey clock based on a continuous beam of cold cesium using optical separated oscillatory fields instead of a microwave cavity. The Raman-Ramsey fringes for clock transition are observed with a contrast of ~68%, and the central fringe width is ~175 Hz for the interaction-zone separation of 30 mm.