Optically induced spin transients in the ground state of atomic sodium

J. Mlynek, Stefan Burschka, Egbert Buhr

J. Mlynek, Martin Rosatzin, Dieter Suter

Wulfhard K. Lange, Fedor M. Mitschke, R. Deserno +1 more

Optical pumping between ground-state Zeeman sublevels recently has attracted much attention as a nonlinear mechanism in optical bistability and tristability, under both steady-state1 and transient conditions.2 If, in addition to optical feedback, the Zeeman-pumped atoms are subjected to a transverse static magnetic field, new phenomena are known to arise,2–5 the most prominent among them being the self-sustained spin precession.4,5 We report on new results and systematic studies on the various types of magnetically induced optical multistabilities in a sodium-filled Fabry-Perot resonator.

Heun Jin Lee

Martin Rosatzin, Dieter Suter, Wulfhard K. Lange +1 more

We report detailed studies of freely evolving Zeeman coherence (Zeeman quantum beats) observed after optically pumping a gas of Na atoms and suddenly turning off the light field. This Zeeman coherence corresponds to a macroscopic magnetization that precesses in an external magnetic field; it is detected with a cw optical probe beam by using polarization-selective detection of the transmitted light. The amplitude and the phase of the signal show a pronounced variation with laser intensity, laser detuning, and the strength of the magnetic field. This dependence was measured on the 3s2S1/2 ground state of sodium, using the D1 line for optical excitation and detection. The experimental data are compared with theoretical predictions based on a Bloch-type equation of motion for an optically driven spin system in a J = 1/2 ground state.

Masaharu Mitsunaga, Makoto Yamashita, Masato Koashi +1 more

Transient four-wave mixing signals were observed in cold sodium atoms. This phenomenon is interpreted as Bragg diffraction of a probe pulse by a population grating of the ground-state hyperfine level induced by pump pulses. The decay time of this grating is directly related to the temperature of the cold atoms and can serve as a novel technique for temperature diagnostics.