Abstract

A ground-state coherence grating involving the magnetic sublevels of the F = 3 ground state in ⁸⁵Rb is created in Doppler-broadened vapor using an excitation pulse that consists of two traveling waves with orthogonally polarized wave vectors along k₁ and k₂. The decay of the grating that is due to thermal motion is probed by a traveling-wave readout pulse along k₂. This results in a scattered signal along k₁ [magnetic grating free-induction decay (MGFID)] that is detected using a heterodyne technique. A second excitation pulse is delayed by T with respect to the first results in a rephased grating at t = 2T [magnetic grating echo (MGE)].¹ Typically, these signals disappear for small buffer-gas pressures (≈50 m Torr) due to velocity-changing collisions.

© 1998 Optical Society of America