Method of hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve with glass solder and hermetically sealed feedthrough device made thereby

摘要

To hermetically seal a fiber optic light guide (1) in a stripped or de-coated state, I.e. the bare optical fiber (2), in a feedthrough sleeve (5) the bare optical fiber (2) is sealed together with the feedthrough sleeve (5) by composite-glass solder with local heating. To make a permanent hermetic glass seal, the feedthrough sleeve (5) is made from an Invar alloy with very low thermal expansion and the composite-glass solder is low-melting with thermal expansion properties adapted to the alloy. The composite-glass solder is molded into prefabricated half-cylinder-shaped pressed parts (7) in a press/sinter technology process, The stripped optical fiber (2) is inserted between the pressed parts (7) arranged in the feedthrough sleeve (5) and sealed by melting the pressed parts together with each other and with the stripped optical fiber and feedthrough sleeve.