ADVANCED MATERIALS FOR FIBER AND WAVE-GUIDE AMPLIFIERS

Recent research into optical fibre and waveguide amplifiers has been c haracterized by steady progress. Advances in the lowest fibre loss 1.5 mu m telecommunications window, where newly installed optical network s operate, include erbium-doped materials with flatter gain spectra an d planar amplifiers in a broad range of materials including oxide glas ses, dielectric crystals and semiconductors. At 1.3 mu m, substantial improvements have been made in praseodymium-doped fluoride fibre ampli fiers and chalcogenide glasses have shown promise for enhanced gain ef ficiency.