title: Five-year frequency stability of a Zeeman stabilized laser.
abstract: A five-year record of the lockpoint frequency of a Zeeman stabilized laser shows an observed drift rate of 0.3 +/- 0.5 MHz/yr following an initial drift of 5.7 +/- 2.2 MHz/yr in the first eighteen months of intermittent operation. A second Zeeman laser drifted at a rate of -0.8 +/- 1.0 MHz/yr over the last 2.5 yr; the frequency drift was -0.2 +/- 0.6 MHz/yr over the last 3.3y r. Empirical temperature correctionsto laser frequency measurements produce a slight variance reduction in the data but no effective bias in the drift estimates.
authors.forename: G S
authors.initials: GS
authors.lastname: Sasagawa
authors.forename: M A
authors.initials: MA
authors.lastname: Zumberge