Observation of Ramsey fringes using stimulated Raman transitions in a laser-cooled continuous rubidium atomic beam

We performed the Ramsey experiment of optical separated oscillatory fields based on a cold continuous \(^{87}\hbox {Rb}\) atomic beam. The beam had a free evolution time of 3.4 ms over a short interaction-zone separation of 42 mm, producing a central Raman–Ramsey fringe with a linewidth of 146 Hz (full width at half maximum). This Raman–Ramsey interferometer based on an atomic beam offers a promising solution for developing a highly stable, compact atomic clock.