Dual-Comb Coherent Raman Spectroscopy with Lasers of 1-GHz Pulse   Repetition Frequency
  We extend the technique of multiplex coherent Raman spectroscopy with two femtosecond mode-locked lasers to oscillators of a pulse repetition frequency of 1 GHz. We demonstrate spectra of liquids, which span 1100 cm$^{-1}$ of Raman shifts. At a resolution of 6 cm$^{-1}$, their measurement time may be as short as 5 microseconds for a refresh rate of 2 kHz. The waiting period between acquisitions is improved ten-fold compared to previous experiments with two lasers of 100-MHz repetition frequencies. 
Kathrin J. Mohler, Bernhard J. Bohn, Ming Yan, Theodor W. H\"ansch,   Nathalie Picqu\'e
physics.optics physics.chem-ph