Preparation of especially pure Ge-Se glasses via germanium monoselenide for Mid-IR fiber optics

Abstract A new method based on the use of germanium monoselenide as a germanium-containing component of the batch for preparing especially pure Ge-Se glasses has been developed. Glass samples of Ge20Se80 composition with hydrogen impurity content in the form of SeH-groups of 1.2–2.6 ppm (at) and of oxygen in the form of Ge-O of 0.1–0.2 ppm (wt) have been produced. A single-index optical fiber with a diameter of 220 μm is fabricated from the purest Ge20Se80 glass sample by using the crucible method. In the spectrum of total optical losses of the single-index fiber, there are selective impurity absorption bands of SeH-groups with an intensity of 1.5 dB/m at a wavelength of 4.51 μm, Ge-O (0.3 dB/m at 7.9 μm), and Si-O (4.1 dB/m at 9.2 μm). The optical losses in the single-index fiber in the spectral range 5–8 μm were at the level of 1.2–1.6 dB/m; the minimum optical losses were 0.9 dB/m at a wavelength of 7.1 μm.