Section 6. Advances in IR materials Infrared transmitting glasses and glass-ceramics

AbstractThe demand for infrared materials which exhibit higher performance is still growing; both on the thermal and mechanical side as wellas on the width of the optical window, with an extension of the transparency towards the long wavelength region to satisfy the require-ments of space applications. Glasses as well as glass-based ceramics offer the advantage of unique rheological properties allowing mold-ing and fiber drawing. In controlling the nucleation/growth process in a chalcogenide glass modified by an alkali halide, it has beenpossible to develop a new generation of glass ceramics containing nanosize grains and transparent in the mid infrared. For the opticalexploration of the universe, new low phonon glasses transparent in the 20 lm region and beyond are needed and to reach this goal a newfamily of telluride glasses was developed in combining Te with Ge with the addition of Gallium or Iodine for stabilization. These newoptical glasses are transparent from 2 to 20 lm and can be drawn into fiber. 2006 Elsevier B.V. All rights reserved.