As fiber amplifiers and lasers achieve higher power, gain fiber designs are pushing toward extremely large-mode area. In this regime, bend-induced distortion of fiber modes becomes large and can severely impact amplifier performance. Previous results describing bend-induced reduction of effective area are reviewed and extended with a numerical analysis of how bend distortion impacts interaction with the gain. Distortion-resistant designs such as the parabolic fiber are shown to substantially improve gain-interaction indicators as well as all other performance metrics simulated, and are predicted to dramatically outperform step-index fibers.
© 2007 Optical Society of America
Fiber and Waveguide Designs
Original Manuscript: November 29, 2006
Revised Manuscript: February 8, 2007
Manuscript Accepted: February 9, 2007
Published: July 19, 2007
John M. Fini, "Design of large-mode-area amplifier fibers resistant to bend-induced distortion," J. Opt. Soc. Am. B 24, 1669-1676 (2007)