New <inline-formula><roman>Er</roman><sup><roman>3+</roman></sup></inline-formula>-doped phosphate glass for ion-exchanged waveguide amplifiers

A new Er 31 -doped phosphate glass exhibiting an excellent durability in both boiling water and NaNO3 molten salt is developed. The ion-exchange process of this glass is investigated by treating glass samples in a variety of salt baths with various exposure times. A planar waveguide with one mode at 1.54 mm and three modes at 632.8 nm is demonstrated. The spectral properties of Er 31 in this glass are charac- terized by measuring absorption and emission spectra and fluorescence lifetimes. The emission cross section of Er 31 in this glass is calculated to be 0.76310 20 cm 2 using McCumber theory. © 1998 Society of Photo-Optical Instrumentation Engineers. (S0091-3286(98)02012-1)