Package for optical devices including optical fiber-to-metal hermetic seal
AssigneeBell Telephone Laboratories, Incorporated
InventorsIrfan Camlibel, Theodore Charles Rich
Life of this patent
Estimating the term…
Abstract
An optical fiber is hermetically sealed to a metal housing containing an optical device (e.g, a semiconductor junction laser or photodiode) by threading and centering the fiber through a thin walled metal tube, filling the tube with solder (e.g., a cylindrical preform) and allowing it to cool. The solder, upon solidifying and cooling, squeezes against the fiber and forms a hermetic seal. The tube-fiber assembly is inserted through an aperture in the housing wall, the fiber is aligned with the optical device and then the tube is soldered to the wall. The housing is out-gassed and then back-filled with a noncorrosive ambient such as nitrogen. Other aspects of the hermetic package, including a laser mount, are also described.
Claims15
A hermetic seal comprising:
- a metal tube wherein one end of the tube has a neck portion forming a narrow diameter opening,
- a bare optical fiber extending axially through the tube and forming an annular space therebetween, the fiber being centered by the neck portion, and
- solder means filling the annular space between the tube and fiber and being confined by the neck portion.
A package for an optical device comprising:
- a metal header,
- a metal housing mounted on the header and having an opening in a wall thereof,
- an optical device mounted on the header and within the housing,
- a metal tube extending through the opening and sealed to the housing, the metal tube having a narrow diameter neck portion,
- a bare optical fiber extending axially through the tube so that the end of the fiber inside the housing is aligned with respect to the optical device, the neck portion centering the fiber within the tube, and
- solder means filling the annular space between the tube and the fiber and being confined by the neck portion.
A method of fabricating a hermetic seal for an optical fiber comprising the steps of:
- (a) inserting the bare fiber axially through a metal tube which has a narrow diameter neck portion,
- (b) centering the fiber by means of the neck portion,
- (c) filling the annular space between the tube and the fiber with a solder preform,
- (d) heating the solder preform until it melts, the solder being confined by the neck portion, and
- (e) allowing the solder to cool until it solidifies.
Dependencies are inferred from the claim text.