Absolute frequency measurement of molecular iodine lines at 514.7 nm, interrogated by a frequency-doubled Yb-doped fibre laser

Abstract

The frequency of several hyperfine components of 127I2 has been measured at 514.67 nm using an optical frequency comb. Among them, the a3 component of the P(13)43-0 transition is recommended by the CIPM for the practical realization of the definition of the metre. The result is consistent with other measurements of the same line within 1.5 kHz of uncertainty, when the collisional shift is taken into account. A frequency-doubled distributed feedback fibre laser has been developed to carry out these measurements.