摘要 |
A stable, single mode fiber amplifier is described. The amplifier consists of a seed source, a passive single clad multimode fiber, an active double clad multimode fiber or a multimode fiber horn and a semiconductor laser pump source. The passive fiber is packaged on a mandrel with a compound radius of curvature such that high order modes in the fiber are stripped from the core leaving only the fundamental mode. This fiber is then spliced to a multimode active fiber of similar core diameter. By exciting only the fundamental mode of this active fiber, stable single mode amplification is achieved. |