Structure, properties and applications of borate glasses

Structure-property relations for different borate glasses and their applications in the fields of optics and related techniques are presented. Optical glasses, with a high borate content mostly in the form of the boroxol ring-structure, with an sp(2) configuration, possess anomalous partial dispersion which allows a minimisation of the 'secondary spectrum' of objectives. Heavy metal borate glasses with high refractive index, nonlinear optical properties and doped with rare earth elements are discussed. Properties of two different types of borosilicate glasses with high and low basicity caused by different M2O/B2O3 ratios, are describes. They have large differences in their intrinsic ultraviolet absorption, excimer laser resistance and colouring behaviour with Ni2+ and Co2+ ions.