Abstract

We have cooled and stopped a beam of cesium atoms using frequency chirped diode lasers. In this technique, a moving atom absorbs and reemits many photons from a counter propagating laser that is frequency swept to keep it in resonance with an atomic transition. The resulting momentum transfer slows the atom. The basic approach is identical to that developed by Hall and co-workers, however, the use of diode lasers allows us to obtain the necessary frequency modulation simply by sweeping the laser injection current. We use two diode lasers tuned to each of the 6s hyperfine ground state levels to drive the 6s—6p_3/2 transitions. Each laser is simultaneously swept over the Doppler profile of the 100°C thermal cesium beam to bring a substantial number to a stop. Using additional fast frequency modulation, the same lasers are used to probe the resulting velocity distribution. This technique allows us to bring ~10⁶ atoms/cm³ to a temperature of 1 K. This method is an extremely simple and inexpensive way to produce cold atoms.

© 1986 Optical Society of America