Kilowatt-power Er~(3+) doped cladding fiber amplifier

摘要

A novel theoretical scheme for high-power Er~(3+) doped fiber amplifier assisted with a long period grating (LPG) is presented. This device consists of an Er~(3+) doped cladding pumped with a high power laser at a wavelength 1480 nm and un-doped core. The LPG imprinted into the fiber core at the beginning of the Er~(3+) doped region transfers a weak signal entering the amplifier in the core-mode of a single mode fiber into a cladding mode, dramatically increasing the effective mode-area of the signal and the threshold powers for unwanted nonlinear effects such as stimulated Raman and Brillouin scattering. The output fiber with the large core provides a high quality output beam.