Nano-engineered glass based optical fiber for fiber laser

Abstract

We have developed the technology for making of dielectric nano-particles doped nano-engineered glass based optical fibers. Two kinds of dielectric nano-particles (DNP) containing silica glass based Yb2O3 doped fibers are made successfully through solution doping (SD) technique. One: Yb2O3 doped yttria-rich alumino-silica nano-particles based optical fiber developed during drawing of D-shaped low RI resin coated large mode area (LMA) optical fiber from the modified preform which annealed at 1450-1550°C for 3 hours under heating and cooling rates of 20°C/min and other: Yb2O3 doped zirconia-germanium-alumino (ZGA) rich yttria-silica nano-particles based optical fibers developed during drawing of normal RI coated single mode optical fiber from the modified preform which annealed at 1000-1100°C for 3 hours under heating and cooling rates of 20°C/min. Fabrication of Yb2O3 doped yttria-rich alumino-silica nano-particles based D-shaped low RI coated large core optical fibers having core diameter around 20.0-30.0 micron was made. The size of DNP nano-particles was maintained within 5-10 nm under doping of 0.20 mole% of fluorine. The start fiber preforms are studied by means of EPMA, EDX, and electron diffraction analyses, revealing phase-separated nano-sized ytterbium-rich areas in their cores. There is a great need to engineer the composition as well as doping levels of different elements within the core glass during the preform making stages to generate phase-separated Yb2O3 doped DNP nano particles in the fiber. The matter concentrates on making of Yb2O3 doped DNP containing optical fibers along with material characterizations, study of spectroscopic properties, photo-darkening phenomena and lasing characteristics. Such kind of nano-engineered glass based optical fibers shows good lasing efficiency with improved photodarkening phenomena compared to the standard silica glass based fiber.