A calcium atomic beam excited in an optical Ramsey geometry was rotated about an axis perpendicular to the plane defined by the laser beams and the atomic beam. A frequency shift of the Ramsey fringes of several kHz has been measured which is proportional to the rotation frequency of the apparatus and to the distance between the laser beams. The results can be interpreted in three equivalent ways as the Sagnac effect in a calcium-atomic-beam interferometer: in the rotating frame of the laser beams either along straight paths or along the curved trajectories of the atoms, or in the inertial atomic frame.

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We have magneto-optically trapped the nine stable isotopes of xenon. Using the Zeeman slowing method to decelerate a beam of xenon atoms in the metastable 6s 3/2 [3/2]z state (notation representing nl J""[E = J""+l]J), we load our trap to a collisionally limited density of more than 10' atoms/cm3.The two odd isotopes are trapped without a repumping frequency, even though they have hyperfine structure. The sensitivity of the trapping process to the laser frequency is exploited to make accurate measurements of the isotope shifts for the 6s 3/2 [3/2]2 -+6p 3/2 [5/2]3 laser-cooling transition and of the hyper6ne constants for "'Xe.PACS number(s): 32.80. Pj, 35.10.Bg, 35.10.Fk In this paper we report the laser cooling and trapping of xenon. We have selectively trapped all nine stable isotopes, including two with less than O. l%%uo natural abundance. We also present accurate measurements of isotope shifts for the 6s 3/2 [3/2]z~6p 3/2 [5/2]3 laser-cooling transition (pair-coupling notation:). Trapping xenon is important for several reasons. Like cesium, it can be cooled to a few microkelvin, or an average speed of about 1 cm/s, in optical molasses. Collisions between such slow xenon, atoms can be studied easily by detection of ions produced by Penning ionization. In addition, Rolston and Phillips have proposed a laser-cooled optical frequency standard which would operate on a two-photon transition between the metastable 6s 3/2 [3/2]2 ( Pz) and 6s 1/2 [1/2]o ( Pc) states [1]. Finally, two of the stable xenon isotopes are fermions, and the remaining seven bosons, so the effects of different spin statistics may be studied using the same element. In our experiment a beam of xenon atoms in the metastable 6s 3/2 [3/2]2 state is decelerated using the familiar Zeeman slowing technique [2] and collected in a magneto-optical trap (MOT) [3]. Our apparatus is shown schematically in Fig. 1. The metastable source, which is similar in design to that of Fahey, Parks, and Shearer [4], is a quartz chamber filled with xenon gas to a pressure of 100 to 250 Pa. Atoms escape from the source with an average speed of about 300 m/s through an aperture 0.14 mm in diameter. The beam is collimated by a 1-mm skimmer aperture placed 1 cm from the source and by an aperture of similar size 30 cm further downstream. As the gas leaves the source, it is excited by a dc discharge running between the skimmer and a cathode filament inside the quartz chamber. Atoms that emerge from the source in the 6s 3/2 [3/2]z state, which has a predicted [5] lifetime of greater than 100 s, are accessible for laser cooling. All of the laser beams in the experiment are derived from a single titanium:sapphire laser, which is locked to the 6s 3/2 [3/2]2~6p 3/2 [5/2]s cooling transition at 882 nm using saturated absorption in a dc discharge cell. Frequencies for the slowing, trapping, and probe laser beams are generated by acousto-optic modulators (AOM's).Our method of Zeeman deceleration draws on techniques developed in Refs.[6] and [7]. The slowing magnet is composed of ...