摘要 |
A molded ceramic or glass ferrule has at least one longitudinal passage, which enables an optical fiber feed through, sealed into a metal housing with glass solder. The metal material in the housing has a slightly higher coefficient of thermal expansion (CTE) than the ferrule material and the sealing glass so that hermetic seal is maintained by a compression stress applied to the ferrule and sealing glass by the housing at operating conditions. When the housing has to be fabricated from a low CTE material, e.g. metal or ceramic, a metal sleeve and stress relief bracket is used to apply the compression stress. |