Optical frequency metrology of an iodine-stabilized He-Ne laser using the frequency comb of a quantum-interference-stabilized mode-locked laser

We perform optical frequency metrology of an iodine-stabilized He-Ne laser using a mode-locked Ti: sapphire laser frequency comb that is stabilized using quantum interference of photocurrents in a semiconductor. Using this technique, we demonstrate carrier-envelope offset frequency fluctuations of less than 5 mHz using a 1 s gate time. With the resulting stable frequency comb, we measure the optical frequency of the iodine transition [I-127(2) R(127) 11-5 i component] to be 473 612 214 712.96 +/- 0.66 kHz, well within the uncertainty of the CIPM recommended value. The stability of the quantum interference technique is high enough such that it does not limit the measurements.