Laser power build-up cavity for high-resolution laser spectroscopy

Abstract

The design, construction, and operation of an optical build-up cavity (BUC) designed primarily for use in molecular beam laser spectroscopy where signal is proportional to laser power, is presented. The design is such that the cavity has no internal adjustment controls, needing only alignment with respect to the laser and molecular beams. When used with a single-mode titanium:sapphire laser, a circulating cw power of 900 W was achieved. The BUC increased the signal to noise of the experiment by a factor of 390 relative to a single crossing of laser and molecular beam without degrading resolution. Performance of the BUC is limited by heating of its mirrors by the high power densities incident upon them (∼3 MW cm−2).