Cavity-mode wavelengths in air are determined by measuring a laser's frequency while it is locked to the mode in vacuum during a calibration step and subsequently correcting the mode wavelength for atmospheric pressure compression, temperature difference, and material aging. Using a Zerodur ring cavity, we demonstrate a repeatability of ±2×10<sup>−8</sup> (3σ), with the wavelength accuracy limited to ±4×10<sup>−8</sup> by knowledge of the absolute helium gas temperature during the pressure calibration. Mirror cleaning perturbed the mode frequency by less than Δ ν/ν∼3×10<sup>−9</sup>, limited by temperature correction residuals.
© 2005 Optical Society of America
(120.2230) Instrumentation, measurement, and metrology : Fabry-Perot
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.3940) Instrumentation, measurement, and metrology : Metrology
Richard W. Fox, Brian R. Washburn, Nathan R. Newbury, and Leo Hollberg, "Wavelength references for interferometry in air," Appl. Opt. 44, 7793-7801 (2005)