Method of manufacturing optical fibers and of the optical devices fibrous

摘要

Light conducting optical filaments and filament systems are formed by depositing on a core of a single transparent glass filament, solid particles of a glass of lower refractive index than the glass of the filament and fusing the particles to form a sheath. A drawn filament is passed through a bath containing a suspension of the glass particles in a liquid such as ethyl lactate, oils such as a mixture of turpene oils, turpentine and wax, or the particles may be deposited by spraying or dipping. The liquid phase is dried off and the coated filament cut to lengths and placed closely packed in a mould having a cross-section desired such as round, hexagonal or square. The mould is then placed in a furnace, the temperature of which is high enough to melt the particles to form a sheath without melting the filaments. The fused bundle may then be drawn out to form a multiple optical filament. The glass used for the filament may be in weight percentages: SiO2 35; B2O3 15; BeO 42; Al2O3 1.5; Na2O 3; ZrO2 3.5; and that of the coating particles: SiO2 70; K2O 6; Na2O 9; B2O3 9; BaO 1; CaO 2.75; Al2O3 2.25.