Comparison between the 127I2 Stabilized He-Ne Lasers at 633 nm and 612 nm of the BIPM and the IMGC

In November 1981, a comparison between BIPM and IMGC He-Ne lasers stabilized to saturated absorption lines of
¹²⁷
I
₂
, at the wavelengths λ = 633 nm and λ = 612 nm has been made at the BIPM. At 633 nm, a repeatability and a reproducibility within +1 × 10
^-11
· ν have been obtained. At 612 nm, a repeatability within a few 10
^-11
· ν only for one laser and a reproducibility of ± 2 × 10
^-10
· ν have been obtained.