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High-Resolution Spectroscopy with Femtosecond Optical Combs

A stabilized femtosecond frequency comb has ~106 stable optical modes spanning hundreds of terahertz, making it an ideal tool for high-resolution spectroscopy. The frequency comb used in these experiments was generated with an octave-spanning, femtosecond, mode-locked laser based on Ti:sapphire with a repetition rate of ~1 GHz. We demonstrate some features of frequency-comb spectroscopy using experiments involving calcium and cesium.