High-power Yb-doped photonic bandgap fiber amplifier at 1150-1200 nm.
Ytterbium-doped solid-core photonic bandgap fiber amplifiers operating at the long-wavelength edge of the ytterbium gain band are reported. The low-loss bandgap transmission window is formed in the very low gain region, whilst outside the bandgap, large attenuation inhibits the exponential growth of amplified spontaneous emission in the huge-gain 1030-1100 nm region. Hence parasitic-lasing-free, high-power amplification with a marked efficiency is enabled. A 32 W output at 1156 nm with a 66% slope efficiency and 30 W output at 1178 nm with a 58% slope efficiency were successfully obtained. To our knowledge, these are the highest output powers generating from active photonic bandgap fibers, as well as from ytterbium-doped fiber lasers at these wavelengths.
Shirakawa
A
A
Institute for Laser Science, University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585, Japan. akira@ils.uec.ac.jp
Maruyama
H
H
Ueda
K
K
Olausson
C B
CB
Lyngsø
J K
JK
Broeng
J
J