TUNABLE 2-FREQUENCY LASERS FOR LIFETIME MEASUREMENTS

We built a compact two-tunable-frequency longitudinally pumped solid-s tate laser specially designed to measure atomic lifetimes. Weak coupli ng between the laser eigenstates permits the obtaining of a continuous ly tunable frequency difference between 0 and 10 GHz. Such a source pr ovides 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 C r4+ in YAG is measured in the zero-fluence limit using a two-frequency Nd:YAG laser at 1064 nm.