IR transmitting glass bar mfr. - melting mixt. in ampoule which also forms casting mould for glass, e.g. selenium:germanium arsenide

摘要

Mixt. (I) is sealed in a glass ampoule contg. neither O2 nor H2O. The ampoule is placed in a sloping position in a furnace, and is heated to melt mixt. (I) so the latter forms a glass cpd. (Ia). During melting, the ampoule is reciprocated in alterate directions of rotation (DOR) so a homogeneous melt is obtd. The melt (Ia) is then cooled, but before it solidifies, the ampoule is tilted so the melt flows into a mould formed by an upper part of the ampoule, and in which a glass bar (Ia) is cast. Bar (Ia) is pref. annealed before being removed from the ampoule, which is pref. made of quartz glass. Mixt. (I) is pref. sealed in the ampoule in vacuo or an inert gas. The method prevents the cracking of the glass bar (Ia) during cooling.