Design and short-term stability of single-frequency CO2lasers

This paper describes a family of sealed-off, single-frequency, TEM
00q
-mode CO
2
lasers with output powers up to 15 watts. Short-term frequency stability[1],[2] measurements of the beat note of two free-running lasers in typical laboratory setups are discussed thereafter. The preliminary measurements indicate a short-term stability of about 5 parts in 10
¹²
for an observation time of 0.05 seconds, and about 5 parts in 10
¹³
, disregarding the discrete spectral lines resulting from 60-Hz modulation by power supply ripple. One or two orders-of-magnitude improvement is predicted, leading to the possibility of measuring the linewidth limit imposed by quantum noise.