Formation of a narrow velocity distribution in an atomic cesium beam by resonant injection laser radiation

An experimental investigation was made of a steady-state deceleration of a beam of cesium atoms by resonant radiation from an injection laser with an external resonator characterized by an emission line of width (Γ < 1 MHz) less than the natural width of the D₂ line. A steady-state narrow peak of the velocity distribution was ~ 13 m/s wide, corresponding to an effective temperature of ~ 1 K.