Reduction of OH super(-) ions in tellurite glasses using chlorine and oxygen gases

• Published in: Journal of materials research 2013-12, Vol.28 (23), p.3226-3233
• Main Authors: Joshi, Purushottam, Richards, Billy, Jha, Animesh
• Format: Article
• Language: English
• Subjects: Absorption
• ISSN: 0884-2914; 2044-5326
• DOI: 10.1557/jmr.2013.341

Absorption losses in tellurite glasses due to OH super(-) ions were reduced by melting the glasses under a reactive atmosphere of Cl2 + O2 gas. Incorporation of dry Cl2 + O2 gas has a major influence on the reduction of OH super(-) species, which is found to be consistent with thermochemical data. Absorption loss due to OH super(-) ions in bulk glasses prepared from the as-received raw materials and processed under a reactive atmosphere was 1000 and 60 dB/m, respectively. Gaussian fits have been used to identify the different species of OH super(-) attached to the structural units present in the glass. All of the OH super(-) species (free and bonded to Te), units can be reduced by melting the starting raw materials in a reactive atmosphere of Cl2 + O2. The net reduction in OH super(-) absorbance at 3.2 mu m was 1.1 cm super(-1), which is equivalent to 500 ppm. OH super(-) reduction in tellurite glasses using O2 gas bubbling shows a reduction in the fundamental absorption band from 1.8 to 0.57 cm super(-1) after 75 min.