Pr3+ doped InF3/GaF3 based fluoride glass fibers and Ga-Na-S glass fibers for light amplification around 1.3 mu m

We have developed three types of highly efficient Pr3+ doped fiber (PDF) am plifiers around 1.3 mu m based on nonoxide glasses. A Pr3+ doped InF3/GaF3 based fluoride glass fiber module (PFDM) has a gain coefficient: 0.29 dB/mW and a signal output power: 15.2 dBm (33 mW) at a pump power of 272 mW. A P r3+ doped chalcogenide system: Ga-Na-S (GNS) single-mode fiber has a larger gain coefficient: 0.81 dB/mW at signal wavelength of 1340 nm for signal in put of -30 dBm. However, GNS-PDFs are best suited for amplification in the wavelength range of 1325-1350 nm when the input power is > -8 dBm. We propo se a hybrid PDF consisting of the above two types of PDFs which has a flatt er gain spectrum in the 1.3 mu m wavelength region and will be able to exte nd the range of the wave division multiplexing (WDM) usage. (C) 1999 Elsevi er Science B.V. All rights reserved.