Observation of atoms laser cooled below the doppler limit

Abstract

We have measured the temperature of a gas of sodium atoms released from "optical molasses" to be as low as 43±20 K. Surprisingly, this strongly violates the generally accepted theory of Doppler cooling which predicts a limit of 240 K. To determine the temperature we used several complementary measurements of the ballistic motion of atoms released from the molasses. © 1988 The American Physical Society.