glasses on the spectral absorption in the wavelength range 2.5–4
m due to the presence of structurally bound water is investigated. It is demonstrated that water in the structure of alkali borate glasses, as in the structure of
alkali silicate glasses, can exist in the form of so-called free and bound hydroxyl groups that are incorporated
into the glass network in different ways. The ratio between the numbers of these forms of structural water in
borate glasses is determined by the synthesis conditions and composition of the glass. The synthesis under dif-
ferent conditions makes it possible to prepare glasses not only with different water contents but also with dif-
ferent ratios between the numbers of free and bound hydroxyl groups.