Velocity-selective optical pumping and Doppler-free spectroscopy

Abstract

We describe a spectroscopic method combining saturated absorption and Zeeman optical pumping. A weak expanded monochromatic laser beam creates a velocity-correlated orientation in an atomic level without optical saturation. A polarization-modulated counterpropagating detection beam provides signals related to simple atomic observables. Combination with magnetic resonance techniques is described. We have applied this method to metastable states of Ne, with nuclear or electronic orientation. Effects of velocity-changing, depolarization (Kastler- or Dehmelt-type pumping) or metastability exchange collisions are discussed.