Rare earth ions doped aluminosilicate and phosphate double clad optical fibres

The paper presents the result of investigations of aluminosilicate (low silica - 25 mol %) and phosphate optical fibres. The methods of glass preparation and their properties are showed. A set of physical measurements including: DTA, DSC, DL analysis, absorption spectroscopy, visible and infrared absorption edges and thermo-physical properties were determined. The stable glass compositions were doped with rare earth elements. Selected properties of obtained glasses are: high transmission, refractive index 1.53-1.68, high solubility of rare earth ions (up to 10 wt %). Double-crucible and rod-in-tube drawing techniques were applied to obtain aluminosilicate and phosphate double clad optical fibres doped with neodymium and ytterbium ions. Luminescence spectra of manufactured glasses and fibres are presented. (authors)