Dataset related to article: Heavy-oxide glasses with superior mechanical assets for nonlinear fiber applications in the mid-infrared. Clément Strutynski, Florian Calzavara, Théo Guerineau, Laura Loi, Romain Laberdesque, Jean-Michel Rampnoux, Steeve Morency, Yannick Ledemi, Yannick Petit, Marc Dussauze, Frédéric Désévédavy, Frédéric Smektala, Sylvain Danto, Lionel Canioni, Younes Messaddeq, Evelyne Fargin, Thierry Cardinal. Optical Materials Express. 2021, volume 11, issue 5, pp. 1420-1430 https://doi.org/10.1364/ome.417699 The data were measured internally with instrumentations belonging to the tem in Bordeaux. UV-Visible-NIR transmission spectra of the glass were recorded in the 0.2 µm - 3.3 µm range using an Agilent Cary 5000 UV-Vis-NIR spectrometer. Transmission in the Mid-IR was collected using a Bruker FTIR Optical losses measurements of single-index fibers were carried out using the cutback method on several meters-long samples. The Raman gain cross-section was calculated from spontaneous scattering spectra measured in in VV (vertical polarization for the excitation and the analysis) configuration using a micro-Raman setup. A spectroscopic phase modulated ellipsometric measurement had thus been performed with an UVISEL apparatus (HORIBA Jobin-Yvon) to determine the refractive index n of the GGBLaY glass, after a fine calibration of the ellipsometre with the reference Silica glass over the spectral range between 0.260 µm to 2 µm thanks to the comparison to literature.