Materials considerations for fiber amplifiers

A principal area of materials research in lightwave communications is special glasses doped with rare earths for laser amplifiers and laser oscillators. Most notable is the stunning success of the erbium doped fiber amplifier operating in the region of 1.55 μm, which is the lowest loss region for fused silica. The zero group dispersion region is at 1.3 microns. The 1.3 micron region has become especially important because so much single mode fiber designed for use in this wavelength is now in use. The most promising laser ion is praseodymium (Pr). Recently some interesting experimental work has been done with dysprosium (Dy). Both ions require non silica host glasses in order to prevent phonon quenching of the fluorescence