Optical fibers in which gain-guiding effects are significant or even dominant compared with conventional index guiding may become of practical interest for future high-power single-mode fiber lasers. I derive the propagation characteristics of symmetrical slab waveguides and cylindrical optical fibers having arbitrary amounts of mixed gain and index guiding, assuming a single uniform transverse profile for both the gain and the refractive-index steps. Optical fibers of this type are best characterized by using a complex-valued ṽ-squared parameter in place of the real-valued v parameter commonly used to describe conventional index-guided optical fibers.
© 2003 Optical Society of America
(060.0060) Fiber optics and optical communications : Fiber optics and optical communications
(060.2310) Fiber optics and optical communications : Fiber optics
(130.2790) Integrated optics : Guided waves
(140.3510) Lasers and laser optics : Lasers, fiber
(230.7370) Optical devices : Waveguides
A. E. Siegman, "Propagating modes in gain-guided optical fibers," J. Opt. Soc. Am. A 20, 1617-1628 (2003)