Laser-cooled Atomic Clocks

Steven R. Jefferts

F Romain

Donald B. Sullivan, Thomas P. Heavner, Leo W. Hollberg +17 more

Rachel Elvin

William M. Klipstein, James M. Kohel, David J. Seidel +3 more

Summary form only given. The long observation times afforded by laser cooling of neutral atoms ushered in a new era of accuracy and stability for cesium atomic clocks. Traditional thermal beam atomic clocks are limited to interaction times of only a few milliseconds, while with laser cooling times of order 1 second have been realized with high stability. Most laser cooled clocks use a "fountain" geometry, in which the atoms are thrown up against the pull of gravity and realize longer times before falling back to the bottom of the apparatus. We have been developing a laser-cooling apparatus for flight on the International Space Station (ISS), with the intention of demonstrating linewidths of the cesium clock transition narrower than can be realized on the ground.

Yan-Ling Meng, Xiaojun Jiang, Jing Wu +4 more

The technique of laser cooling of atoms gives an opportunity to improve the performance of atomic clocks by using laser-cooled atoms. The most successful cold atom clock, called the atomic fountain, is now widely used as the primary frequency standard in many labs. The cold atom clock for satellite applications, however, has not been reported so far due to special requirements of space applications. Here, we report the development of an engineering model of a satellite-borne cold atom clock, which satisfied all requirements of in-orbit operation. The core of the clock’s principle is the laser cooling of atoms by diffuse laser lights inside the microwave cavity. The structure of the physics package is presented, and its main parameters are also given. The principle and design of the optical bench are described. The initial test results are presented, and the possible improvements are also discussed.