Abstract
To laser cool atoms in an atomic beam, it is necessary to repeatedly excite the atoms with a counterpropagating laser beam. One method of doing this uses a "chirped" laser frequency to compensate for the changing Doppler shift of the slowing atoms. Although most implementations of chirp cooling use only a single swept frequency,1,2 improved cooling efficiency can be obtained through multifrequency chirp cooling3,4 or broadband white-light cooling.5 We demonstrate a multifrequency chirp method using two simultaneously swept EM sideband orders that we used to bring a significant fraction of a thermal lithium beam to near-zero velocity. With this method, atoms with high initial velocities are slowed first by interaction with a second-order sideband and then additionally slowed by a first-order sideband. For a given frequency sweep range, this two-sideband technique requires an FM bandwidth that is only one-third that of single frequency chirp cooling. This improvement is especially important for cooling atoms, such as lithium, that have large initial Doppler shifts and therefore require a large frequency sweep range.
© 1992 Optical Society of America
PDF ArticleMore Like This
C. E. Wieman and R. N. Watts
WC4 International Laser Science Conference (ILS) 1986
R. G. DeVoe
QMA4 Quantum Electronics and Laser Science Conference (CLEO:FS) 1992
R. G. DeVoe
ThF4 International Quantum Electronics Conference (IQEC) 1992