Laser saturation spectroscopy of atoms

J. Kowalski, Ronny Neumann, Frank N. Trager +1 more

Michele Marrocco

In laser spectroscopy, saturation of atomic or molecular transitions cannot be ignored, even at modest laser intensities. The saturation status is customarily diagnosed from measurements of saturation curves describing the dependence of spectroscopic signals on laser intensity. I propose an alternative method that relies on a geometric comparison of the spatial laser profile with images of the spectroscopic quantity under investigation. A single image can be used to determine the saturation status and its associated saturation laser intensity.

Theodor W. Hänsch

Genko T. Genov, Tim Lellinger, Thomas Halfmann +1 more

We present and analyze a bichromatic version of the well-known saturation absorption spectroscopy technique used to stabilize lasers to atomic resonances without Doppler broadening. We show that the spectroscopic properties can be transferred between two transitions at very different wavelengths by spectral hole burning in a Doppler-broadened atomic ensemble. Specifically, we demonstrate that this technique can be used to stabilize a laser to the D1 line of Rb87 by obtaining a saturation absorption spectrum with a strong pump laser stabilized to the D2 line. This allows for more freedom in the choice of the probe laser frequency offsets compared to conventional saturation absorption spectroscopy. We compare our experimental results to an analytical model and numerical results based on rate equations.

ARTHUR L. SCHAWLOW

M. Allegrini