[OPTICAL REVIEW Vol. 4, No. 5 (1997) 550-552]

Tunable Two-Frequency Lasers for Lifetime Measurements

Marc BRUNEL,1 Olivier EMILE,1 Fabien BRETENAKER,1 Albert LEFLOCH,1 Bernard FERRAND2 and Engin MOLVA2

1Laboratoire d'Electronique Quantique-Physique des lasers, Unité Mixte de Recherche du Centre National de la Recherche Scientifique 6627, Université de Rennes I, Campus de Beaulieu, F-35042 Rennes Cedex, France, 2Laboratoire d'Electronique, de Technologie et d'Instrumentation, Déartement Optronique, Commissariat é l'Energie Atomique, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France

(Received May 26, 1997; Accepted June 1, 1997)

We built a compact two-tunable-frequency longitudinally pumped solid-state laser specially designed to measure atomic lifetimes. Weak coupling between the laser eigenstates permits the obtaining of a continuously tunable frequency difference between 0 and 10 GHz. Such a source provides either a linear polarization rotating at such frequencies, or a sinusoidally modulated intensity with a 100% modulation amplitude. As an example, the fluorescence lifetime of the first excited state of Cr4+ in YAG is measured in the zero-fluence limit using a two-frequency Nd:YAG laser at 1064 nm.

Key words : fluorescence lifetime, solid-state lasers, helicoidal eigenstates, heterodyne lasers