Starting from the paraxial wave equation, an analytic expression for filament threshold in fiber lasers is derived. The occurrence of filamentation is determined by the larger of two thresholds, one of perturbative gain and one of spatial confinement. The threshold value is approximately a few megawatts, depending on the parameters of the fiber.
© 2007 Optical Society of America
Fiber Optics and Optical Communications
Original Manuscript: November 22, 2006
Revised Manuscript: May 30, 2007
Manuscript Accepted: June 20, 2007
Published: August 22, 2007
Lei Sun and John R. Marciante, "Filamentation analysis in large-mode-area fiber lasers," J. Opt. Soc. Am. B 24, 2321-2326 (2007)