A continuous cold atomic beam interferometer

We demonstrate an atom interferometer that uses a laser-cooled continuous beam of 87Rb atoms having velocities of 10–20 m/s. With spatially separated Raman beams to coherently manipulate the atomic wave packets, Mach–Zehnder interference fringes are observed at an interference distance of 2L = 19 mm. The apparatus operates within a small enclosed area of 0.07 mm2 at a bandwidth of 190 Hz with a deduced sensitivity of 7.8×10−5 rad/s/Hz for rotations. Using a low-velocity continuous atomic source in an atom interferometer enables high sampling rates and bandwidths without sacrificing sensitivity and compactness, which are important for applications in real dynamic environments.