Optical fiber-to-metal hermetic seal

摘要

A process for hermetically sealing an optical fiber to a metal housing is described. An optical fiber 12 is threaded through a thick-walled metal tube 10 which has a bore 11 of slightly larger diameter than the fiber. The tube and fiber are inserted in a pneumatically operated collet and uniform radial pressure is applied to the tube to form a unitary hermetic assembly. Metal tube 10 is characterized in that it has or, prior to forming the assembly, is annealed to have a Rockwell hardness of less that 15 T 15. At this value the metal is soft and the pressure required to cause the metal to cold flow around the fiber is less than that required to break the fiber. The tube is then soldered or otherwise secured in a hole in the housing, thus completing the hermetic seal. Such a seal is useful in hermetic packaging of optical devices. It is advantageous over the prior art for its simplicity and inexpensiveness. The technique is suited to high yield mass production of reliable seals.