Methods and apparatus for hermetically sealing an optical fiber in a feedthrough
connection. In brief overview, the optical fiber is mounted in a housing whose
physical properties differ from that of the fiber by utilizing a structure in accordance
with the present invention. The structure, typically in transition bushing form,
is formed from at least two materials, such that the physical properties of a first
material are selected to match the physical properties of the optical fiber, and
the physical properties of a second material are selected to match physical properties
of the housing. When the matched physical properties are the coefficients of thermal
expansion (CTE) of the fiber and the housing, the result is a fiber optic mounting
that remains hermetically sealed despite changes in ambient temperature that would
typically induce stresses in the seal, potentially causing its failure.
