Frequency stabilization of a high power argon laser

A technique for frequency stabilizing a high power, single frequency argon laser is described which offers certain advantages over those that have already been reported. This system is capable of maintaining a relative short term frequency stability of the order of +/-2 parts in 10(9) and a long term stability (2 h) of about +/-5 parts in 10(9) for the 5145-A line at a power level of 750 mW. This short and long term stability is achieved by means of a multiple feedback loop composed of an optical cavity discriminator which is stabilized against an iodine vapor absorption line.