Saturated Absorption with Spatially Separated Laser Fields: Observation of Optical "Ramsey" Fringes

Abstract

We have observed Ramsey's interference fringes in the optical region using saturated-absorption techniques in a fast atomic beam. We discuss their physical origin and describe an optical configuration that guarantees fringes of high symmetry. This technique, with its high-resolution potential, should lead to dramatic improvements in spectral measurements.