Low cost and environmentally improved infrared transmitting germanate

Abstract

This patent discloses the composition of germanate glass and a new method for its fabrication. The composition comprises germanate, the oxide of an alkali earth group, Al.sub.2 O.sub.3, ZnO, a halides compound eg. CaF.sub.2, CaCl.sub.2 and so on,, and can combine with a series of oxygenous compounds such as silicate, borate, phosphate, arsenate, tellurate and so on, if required. The addition of an alkali oxide could increase the glass formation rate and homogeneity, and the defects of devitrification, cord, knot, and blister are reduced. Its fabricated methods which consist of the reduction pressure melting with the addition of a halide and the drying procedure. The germanate glass body that is made is colorless and transparent and it can increase the transmittance of infrared from 20% to greater than 60% in the wave length 2.75-3.0 .mu.m. The price of producing the germanate glass is decreased and the transmittance of this composition system increased from 5% to 80%.