FABRICATION OF LOW-LOSS AND HIGH-DELTA-N SINGLE-MODE FLUORIDE FIBER FOR 1.3 MU-M PRASEODYMIUM-DOPED FIBER AMPLIFIERS

The crystallization properties of ZrF4-based fluoride glasses containing PbF2 are clarified and single-mode fibers for an optical amplifier operating at 1.3 mu m are fabricated. The crystallization tendency increases as the PbF2 content of the glasses increases and the optimum PbF2 content ranges from 11 to 12.5 mol % in terms of glass stability and refractive indices. The 4%-Delta n single-mode fiber with a transmission loss of 44 dB/km at 1.2 mu m was prepared as the amplifier host fiber. ZrF4-based glass with a PbF2 content of 11 mol % was used as a core glass and HfF4-based glass was used as a cladding glass. (C) 1995 American Institute of Physics.