Abstract

Atom interferometers are expected to be used as sensitive detectors in a variety of precision measurements; several versions were presented for various purposes until now. We have developed an atom interferometer comprised of a Ca thermal atomic beam and three copropagating traveling laser beams. The interferometer is a simple single interferometer and is expected to be of higher visibility than the atom interferometer with four laser beams.¹ Figure 1 shows the experimental setup. To get three parallel laser beams with an intensity ratio of 1:4:1, an incident laser beam is divided into three beams by an optical parallel plate with different reflectivity on each point of reflection. The beam intervals between the adjacent laser beams are 5 mm. The parallel plate is aligned so that a center laser beam interacts with the Ca thermal atomic beam rectangularly. With excitations of π/2, π, and π/2 pulses for atoms with the most probable velocity, interference fringes with a visibility of 25% could be obtained. The visibility is a few percent less than the calculated value but is 5% higher than that with four excitations of π/2 pulses, as shown in Fig. 2.

© 1998 Optical Society of America