Stark cell noise reduction of a CO 2 laser beam

A technique is demonstrated for reducing the rapid intensity fluctuations in the beam of a single frequency, polarized CO 2 laser tuned to the P(20) transition at 10.6 μm. The method uses a Stark-tunable absorption line in NH 2 D to compensate for the fluctuations of the laser output. Substantial reductions in laser beam intensity noise have been obtained. The method may be applied to other lines of the CO 2 laser and indeed to other types of lasers.