Fourier synthesis of continuous-wave Raman sidebands generated through an intracavity Raman-resonant four-wave mixing

We report here the first demonstration of the generation of a continuous-wave (cw) ultrashort pulse train with a repetition rate of more than 10 THz. Each pulse included in this pulse train had duration of less than 20 fs and a separation between pulses was 57 fs corresponding to a repetition rate of 17.6 THz. This was achieved by Fourier synthesis of phase-locked multifrequency cw lines separated by a frequency of 17.6 THz. This emission was generated through an intracavity Raman-resonant four-wave mixing process in a dispersion-compensated high-finesse cavity pumped by a single-frequency laser.