중적외선 응용을 위한 텔루라이트계 광학유리 제조 및 광특성 분석

Abstract

TeO2 and PbO based optical glasses were fabricated by conventional glass melting method and their optical properties were analyzed for mid-infrared applications. The optical transmittance of 60TeO2-20ZnO-20BaO(in mol%) glass was 62 ~ 73% in the mid-infrared range of 3 ~ 6 ㎛. It was higher than that of 50PbO-25Bi2O3-25Ga2O3(in mol%) glass. IR edge wavelength of the TeO2 based glass was 6.5 ㎛ and it was shorter than that of the PbO based glass (~7.5 ㎛). In also, effect of Bi2O3 content on the IR properties was investigated in the 60TeO2-(20-x/2)ZnO-(20-x/2)BaO-xBi2O3 (x= 0 ~ 12, in mol%) glass. The IR edge shifted to the longer wavelength in the range from 6.4 to 6.6 ㎛ according to the increase of the Bi2O3 content in the glass. It was also found that UV edge shifted from 350 to 400 nm and the overall mid-infrared transmittance slightly decreased with the increase of the Bi2O3 content. Finally, effect of gas atmospheric condition during glass melting process on the reduction of OH absorption in the TeO2 based glasses was investigated. Several gas compositions such as Ar, N2, N2:O2(1:1), He:O2(1:1) gases with different gas flows (0.4 ~ 1.6 L/min) were tested and the optical properties of the glasses were investigated to find OH reduction effect in the melting process.