Fabrication and characterization of a water-free mid-infrared fluorotellurite glass

Using a physical and chemical dehydration technique and a high-pressure, ultradry O-2 atmosphere in a semiclosed steel-chamber furnace, we fabricated a group of fluorotellurite glasses with a composition of (90-x)TeO2-xZnF(2)-10Na(2)O (mol.%, x 0-30). For x 30, no OH absorption was observed in the range of 0.38-6.1 mu m. This is the first report of a water-free mid-IR fluorotellurite glass, to our knowledge, offering the common advantages of a robust oxide glass and an IR-transparent fluoride one. Besides optimized linear transmittance and absorption, the nonlinear refractive indices and Raman gain coefficients are reduced. These results are discussed in the context of mid-IR high-power laser generation and transmission. (C) 2011 Optical Society of America