Dispersion of pure GeO2 glass core and f-doped GeO2 glass cladding single-mode optical fibre

The letter investigates the dispersion of GeO2 glass core and F-doped GeO2 glass cladding single-mode optical fibre. It is estimated that the total dispersion goes to zero at about ? = 1.77 ?m. The material dispersions of these glasses are also measured. Material dispersion of GeO2 glass, which contains fluorine of 0.41 wt%, vanished at ? = 1.722?m. This occurs at ? = 1.734 ?m for pure GeO2 glass.