Manipulating atomic velocities using diode lasers

Wolfgang A. Ertmer, R. Blatt, J. L. Hall +1 more

Richard N. Watts

Toshio Yoneyama, Shunichi Sato

Carl Wieman, Leo W. Hollberg

Richard N. Watts, Carl Wieman

We have used counterpropagating radiation from a diode laser to cool and stop a beam of cesium atoms. The laser frequency was chirped to keep it in resonance with the slowing atoms. The same laser was used to probe the resulting velocity distributions. We have cooled more than 1010 atoms/sec to a temperature of 1 K. This is an extremely simple and inexpensive way to manipulate atomic velocities and has a wide range of possible applications.

Richard N. Watts

The results of two experiments involving the rapid frequency modulation of diode lasers are presented. In the first experiment, a cesium beam of 10('14) atoms/sec is produced with more than 98% of the atoms in a single spin state. The beam is polarized by optically pumping it with a single diode laser whose frequency is switched between the 6s(F = 4)-6p(,3/2)(F = 5) and 6s(F = 3)-6p(,3/2)(F = 4) transitions at 100 kHz. To do this, the frequency response of a diode laser to changes in injection current was first determined and the injection current modified to force a jump of 9.2 GHz in 1.5 (mu)sec. The same laser is used to probe the atomic population distribution simultaneously. In the second experiment, two diode lasers, tuned to the 6s(F = 4)-6p(,3/2)(F = 5) and 6s(F = 3)-6p(,3/2)(F = 4) transitions, are used to cool and stop a beam of cesium atoms. The laser frequencies are swept to keep them in resonance with the slowing atoms. The same lasers are used to probe the resulting velocity distribution. More than 10('10) atoms/sec are slowed to a velocity of 0 (+OR-) 15 m/sec, corresponding to a temperature of 1(DEGREES)K. Both of these experiments demonstrate extremely simple and inexpensive ways to manipulate atomic cesium.