SIMPLEST ATOMIC SYSTEM FOR SUB-DOPPLER LASER COOLING

Sub-Doppler laser cooling requires optical pumping among differently l ight-shifted ground-state sublevels. We describe a study of the simple st possible angular-momentum configuration that permits all sub-Dopple r cooling phenomena. The J(g) = 1 double-line arrow pointing right J(e ) = 0 angular-momentum configuration shows recoil-limited cooling in t he two most well-known types of polarization gradient, magnetically in duced laser cooling, velocity-selective resonances, transient cooling, and velocity-selective population trapping.