Improvement in the beam quality of large-mode-area fiber amplifier output through fiber tapering

摘要

It is shown that the introduction of an adiabatic taper at the output end of a large-mode-area fiber amplifier can greatly improve the beam quality factor of the single-mode output beam when the core refractive index profile departs from an ideal step-index distribution. The deleterious impact of higher-order modes is also analyzed.