A phase-locked frequency comb in the near infrared is demonstrated with a mode-locked, erbium-doped, fiber laser whose output is amplified and spectrally broadened in dispersion-flattened, highly nonlinear optical fiber to span from 1100 to >2200 nm . The supercontinuum output comprises a frequency comb with a spacing set by the laser repetition rate and an offset by the carrier-envelope offset frequency, which is detected with the standard f-to- 2f heterodyne technique. The comb spacing and offset frequency are phase locked to a stable rf signal with a fiber stretcher in the laser cavity and by control of the pump laser power, respectively. This infrared comb permits frequency metrology experiments in the near infrared in a compact, fiber-laser-based system.
© 2004 Optical Society of America
(120.3930) Instrumentation, measurement, and metrology : Metrological instrumentation
(140.3510) Lasers and laser optics : Lasers, fiber
(190.4370) Nonlinear optics : Nonlinear optics, fibers
Brian R. Washburn, Scott A. Diddams, Nathan R. Newbury, Jeffrey W. Nicholson, Man F. Yan, and Carsten G. Jrgensen, "Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared," Opt. Lett. 29, 250-252 (2004)