Optical frequency measurements with a reference cavity stabilized femtosecond laser for improved short term stability

Summary form only given. We have shown that both the pulse to pulse carrier-envelope phase slip, /spl Delta//spl phi/, and the round-trip time of the pulse in the laser, /spl tau//sub RT/, can be fixed by stabilization to a long (equal to the laser cavity length) Fabry-Perot reference cavity. Contrary to other techniques, our stabilization scheme does not depend on an independent, stable radio frequency (RF) source to lock the laser repetition rate. We demonstrate here the use of such a stabilized system to measure directly optical frequencies, and apply our system to an accurate measurement of the dispersion of air at 800 nm.