A complete characterization is given of the effects of homogeneous and inhomogeneous gain broadening on the mode-locking dynamics and stability of a laser operating simultaneously at N frequency channels. Using a low-dimensional model for the wavelength-division multiplexing interactions of the governing cubic-quintic master mode-locking equation, the interplay of the gain dynamics can be completely classified. This gives a simple way to characterize the laser performance and the parameter regimes under which stable multifrequency operation can be achieved. The analysis shows that a small amount of inhomogeneous gain broadening is critical for the multifrequency operation. The model further provides a simple framework for understanding the stability of mode-locked pulses at multiple frequencies, thus contributing to the characterization of the increasingly important and timely technology of dual-frequency and multifrequency mode-locked laser cavities.
© 2008 Optical Society of America
Lasers and Laser Optics
Original Manuscript: May 8, 2008
Revised Manuscript: June 18, 2008
Manuscript Accepted: July 1, 2008
Published: August 19, 2008
Brandon G. Bale, J. Nathan Kutz, and Edward D. Farnum, "Dynamics of multifrequency mode-locking driven by homogenous and inhomogenous gain broadening effects," J. Opt. Soc. Am. B 25, 1479-1487 (2008)