This work is supported by DARPA under Young Faculty Award No. HR0011-08-1-0065 and National Science Foundation under Grant No. 0925992.
Fiber optics, Optical communications
We theoretically analyze gain guiding in large-core Bragg fibers, to be used for large-mode-area laser amplifiers with single-transverse-mode operation. The signal is gain-guided in a low-index core, whereas the pump is guided by the photonic bandgap of the Bragg cladding to achieve good confinement. The high-index layers in the Bragg cladding are half-wave thick at the signal wavelength in order to eliminate Bragg reflection, reducing the Bragg fiber effectively to a step-index fiber for gain guiding.
Xianyu Ao, Tsing-Hua Her, and Lee W. Casperson, "Gain guiding in large-core Bragg fibers," Opt. Express 17, 22666-22672 (2009).