High Peak Power Fiber Amplifiers Operating at Eye-Safe Wavelengths

Recent advances in fiber technology have enabled a dramatic increase in the power delivered from fiber based amplifiers and lasers. This is particularly true at the 1060-nm wavelength where ytterbium (Yb)-doped fibers operate, with state-of-the-art peak powers now approaching 1 MW (1 mJ and 1 ns) delivered with single-mode, near diffraction limited beam quality. However, progress on scaling fiber-based eye-safe devices, such as those operating around the 1550-nm wavelength regime, based on Er:Yb (erbium:ytterbium) co-doped fibers has been much slower. The progress at this wavelength range hampered by the lack of suitable large mode area (LMA) fibers.