We present an analytical theory based on wave kinetic equations that describes a Raman fiber laser (RFL) generation spectrum. It is shown both theoretically and experimentally that the quasi-degenerate four-wave mixing between different longitudinal modes is the main broadening mechanism in the one-stage RFL at high powers. The shape and power dependence of the intracavity Stokes wave spectrum are in excellent quantitative agreement with predictions of the theory.
© 2006 Optical Society of America
Original Manuscript: July 11, 2006
Revised Manuscript: August 2, 2006
Manuscript Accepted: August 2, 2006
Published: September 25, 2006
S. A. Babin, D. V. Churkin, A. E. Ismagulov, S. I. Kablukov, and E. V. Podivilov, "Spectral broadening in Raman fiber lasers," Opt. Lett. 31, 3007-3009 (2006)