Abstract
1.6μm band fiber amplifiers must be developed for future optical transmission line monitoring systems and ultra-wide band wavelength division multiplexing systems. The 1.6μm band Er3+-doped fiber amplifier (EDFA) and the Tm3+-doped fluoride fiber amplifier have been proposed as candidates. The former can be realized by shifting the amplification band of a 1.55μm band EDFA, by using a long Er3+-doped fiber. The latter employs the tail of the 1.8μm amplification band of Tm3+-doped fluoride fiber by the doping of terbium ions in the cladding. This paper reviews the amplification mechanisms and basic characteristics of 1.6μm band EDFAs and TDFAs.
