The FM spectroscopy technique has been applied to two frequency-doubled Nd:YAG lasers to achieve absolute frequency stabilization against the hyperfine structure components of the rovibronic <i>P</i>(54) 32–0 iodine line at 532 nm. A fractional frequency stability of 2 × 10<sup>−13</sup> τ<sup>−1/2</sup> has been obtained for integration times in the range of 1 ms < τ < 10 s. For longer integration times the stability level remains below 10<sup>−13</sup>, reaching a minimum value of 4.6 × 10<sup>−14</sup> at 100 s. This high stability level is, to our knowledge, the best value achieved against iodine lines by this locking method and for a fully transportable system.
© 1999 Optical Society of America
(020.2930) Atomic and molecular physics : Hyperfine structure
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(120.3940) Instrumentation, measurement, and metrology : Metrology
(120.4800) Instrumentation, measurement, and metrology : Optical standards and testing
(300.6320) Spectroscopy : Spectroscopy, high-resolution
Gianluca Galzerano, Cesare Svelto, Elio Bava, and Fabrizio Bertinetto, "High-frequency-stability diode-pumped Nd:YAG lasers with the FM sidebands method and Doppler-free iodine lines at 532 nm," Appl. Opt. 38, 6962-6966 (1999)