Eros Modone

Fluorine in MCVD optical fibers

Fluorine incorporation in silica glass network has been investigated using CCl 2 F 2 (Freon-12) as a source. Considerations on the stoichiometry of the reactions involved in CVD processes and experimental results on the refractive index are detailed. The data are collected in a ternary diagram that is proposed as a useful graphic representation in order to identify iso-index curves.

Different processes for the preparation of fluorozirconate glasses

Abstract Different processes for the preparation of fluorozirconate glasses (ZBLAN) have been investigated by infrared spectroscopy (IR) and x-ray diffraction (XRD) on fluoride powders, during the reaction. Glasses have been prepared with 20-10-5-0 (% weight) ammonium bifluoride (NH4F·HF) or with nitrogen trifluoride (NF3) as fluorinating agent. In order to improve the quality of the glasses, small percentages (about 5%) of NH4F·HF are a good compromise between fluorination and hydration of starting products; NF3 is very effective during the fluorination step of the preparation: our electron spin resonance measurements (ESR) on these last glasses after γ-irradiation (20 Mrad), do not detect any O2 signal.

GeO 2 Doped High N.A. Multimode Fibre Made By Pressurized MCVD

High numerical aperture multimode fibres for local area applications are presented. Using the MCVD technique with inner pressure control it is possible to dope the core only with Ge02 without cracks along the preform. A maximum value of 27% molar concentration of GeO2 has been achieved. Fibres have been made with nm N.A. greater than 0.3 and with a loss below 4 dB/km at λ= 850 nm and below 1 dB/km at 1300 nm.

Determination of trace amounts of copper and iron in zirconium oxychloride by inductively coupled plasma atomic emission spectrometry using the standard additions method

Inductively coupled plasma atomic emission spectrometry has been used in order to evaluate the concentrations of iron and copper impurities in zirconium oxychloride. After suitable wavelength selection an analytical procedure has been developed in order to take account of the heavy matrix effects in the spectroscopic determination of both species, using the standard additions method.

PL measurements on fluorozirconate glasses

Several fluoro-zirconate glasses, ZBLA type, have been prepared in CSELT. Fluorides, as raw materials and the technique of melting in Pt crucible were initially adopted.