  A chirped-pulse interleaving method is reported for generation of dual
optical frequency combs based on electro-optic phase modulators (EOM) in a
free-running all-fiber based system. Methods are discussed to easily modify the
linear chirp rate and comb resolution by more than three orders of magnitude
and to significantly increase the spectral bandwidth coverage. The agility of
the technique is shown to both capture complex line shapes and to magnify rapid
passage effects in spectroscopic and molecular dynamics studies of CO2. These
methods are well-suited for applications in the areas of remote sensing,
reaction dynamics, and sub-Doppler studies across the wide spectral regions
accessible to EOMs.
