Applications of antimony–silicate glasses for fiber optic amplifiers

Abstract

The performance of rare-earth-doped fiber amplifiers based on antimony–silicate glasses is reviewed. Erbium-doped antimony silicate has intrinsically flat gain in the conventional (C-band) erbium gain window enabling a 48 nm C-band amplifier. A modified composition induces a substantial red-shift in the signal excited state absorption, which in turn enables bandwidth extension of the long wavelength (L-band) to 1620 nm. Thulium-doped antimony silicates provide up to 60 nm of bandwidth in the S-band ranging from 1460 to 1520 nm. Local coupling of the thulium ions to low phonon sites prevents the lifetime quenching typical of thulium-doped silicates. Thulium-doped antimony silicates provide an efficient wider-band alternative to fluoride materials.