A combination of continuous-wave optical parametric oscillator and femtosecond frequency comb for optical frequency metrology

摘要

We combine a tunable continuous-wave optical parametric oscillator and afemtosecond Ti:Sapphire laser frequency comb to provide a phase-coherent bridgebetween the visible and mid-infrared spectral ranges. As a first demonstrationof this new technique we perform a direct frequency comparison between aniodine stabilized Nd:YAG laser at 1064 nm and an infrared methane opticalfrequency standard at $3.39 \mu$m.