The frequency-domain mode comb of a Ti:sapphire femtosecond laser centered at 350 THz is broadened to 150 THz (full width at -30 dBc) by self-phase modulation in a single-mode optical fiber. By phase locking continuous-wave lasers to elements of the comb near 1064 and 778 nm, we measure the 104-THz frequency gap between these two lasers with a relative uncertainty of 2.7 × 10<sup>-11</sup> in 1 s.
© 2000 Optical Society of America
Scott A. Diddams, David J. Jones, Long-Sheng Ma, Steven T. Cundiff, and John L. Hall, "Optical frequency measurement across a 104-THz gap with a femtosecond laser frequency comb," Opt. Lett. 25, 186-188 (2000)