We have developed and characterized a pair of Doppler-free acetylene-stabilized diode laser frequency standards as optical communications references. The Allan deviation σ/f of an individual system reaches a minimum of 4×10<sup>-14</sup> at a sampling time of 5000 s, and the long-term lock-point repeatability is found to be 0.4 kHz (one standard uncertainty), corresponding to a fractional uncertainty of 2×10<sup>-12</sup> . Using a combination of a frequency chain and a self-referenced femtosecond comb, we have measured the frequency of line P(16) of the ν<sub>1</sub>+ν<sub>3</sub> overtone band of <sup>13</sup>C <sub>2</sub>H<sub>2</sub> to be 194 369 569 385.9 (3.0) kHz. The uncertainty of this number is limited solely by the reproducibility of the standards.
(060.4510) Fiber optics and optical communications : Optical communications
(140.2020) Lasers and laser optics : Diode lasers
(140.5960) Lasers and laser optics : Semiconductor lasers
(300.6260) Spectroscopy : Spectroscopy, diode lasers
(300.6390) Spectroscopy : Spectroscopy, molecular
(300.6460) Spectroscopy : Spectroscopy, saturation
Christopher S. Edwards, Helen S. Margolis, Geoffrey P. Barwood, Stephen N. Lea, Patrick Gill, Guilong Huang, and William R. C. Rowley, "Absolute frequency measurement of a 1.5-µm acetylene standard by use of a combined frequency chain and femtosecond comb," Opt. Lett. 29, 566-568 (2004)