Fabrication of Active Fluoroaluminosilicate Fibers for High-Power Fiber Lasers

Abstract

An all-vapor phase modified chemical vapor deposition (MCVD) process has been proposed for the fabrication of active-fiber preforms with a fluorine-rich F–Yb₂O₃–GeO₂–Al₂O₃–SiO₂ glass core. The composition of the glass has been shown to differ significantly from that of the vapor–gas mixture because of the formation of GeF₄, AlF₃, and YbF₃, which are volatile at typical MCVD temperatures. We have identified F–Yb₂O₃–GeO₂–Al₂O₃–SiO₂ glass deposition conditions that ensure uniform distributions of the dopants along the length of the preform.