Scientists at JILA, a collaboration of the University of Colorado and the National Institute of Standards and Technology, all in Boulder, have demonstrated that near-IR erbium-doped fiber lasers can produce well-defined frequency combs for use in optical frequency metrology in telecommunications. They reported their findings in the Dec. 2 issue of Optics Express.

The group phase-locked the fiber laser's repetition rate and frequency-locked its carrier frequency to a Kerr-lens mode-locked Ti:sapphire laser's comb. A two-stage setup synchronized the repetition rate of the lasers with piezoelectric transducers that selectively applied stress to the fiber. Optically mixing the pulses from the lasers in BBO revealed an rms timing jitter of 12.4 fs. The rms frequency jitter was 355 kHz.