Optical fiber hermetic seal
First Claim
1. An optical fiber hermetic seal comprising a mass of fusible alloy embracing a length of the fiber, the fusible alloy exerting pressure on the fiber at an interface between the alloy and the fiber, the alloy characterized by appreciable expansion during solidification, the mass of fused alloy being generally cylindrical in shape, the fiber located on a central longitudinal axis of the cylindrical mass of alloy, and the mass of fused alloy being embraced by a hollow cylindrical tube.
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Accused Products
Abstract
A hermetic seal for an optical fiber is fabricated by casting or molding a mass of fusible alloy around the fiber so that the alloy solidifies within a confined space. The alloy used is characterized by low thermal coefficient of expansion, minimal relaxation after solidification, and appreciable expansion as it solidifies, thereby to create a stable pressure contact at its interface with the optical fiber. The solidified mass may be subsequently soldered into a passage through a wall of a fiber optic device package. Alternatively, the mold within which the mass of alloy is encased or molded may, itself, be soldered into the passage.
79 Citations
17 Claims
- 1. An optical fiber hermetic seal comprising a mass of fusible alloy embracing a length of the fiber, the fusible alloy exerting pressure on the fiber at an interface between the alloy and the fiber, the alloy characterized by appreciable expansion during solidification, the mass of fused alloy being generally cylindrical in shape, the fiber located on a central longitudinal axis of the cylindrical mass of alloy, and the mass of fused alloy being embraced by a hollow cylindrical tube.
- 7. A method of making a hermetic seal at the surface of an optical fiber, the method comprising supporting a part of the optical fiber in a predetermined position, establishing an enclosed chamber around a part of the fiber, introducing molten fusible alloy through a port in a wall of the chamber thereby to fill the enclosed chamber, the fusible alloy characterized by appreciable expansion on solidification, and solidifying the fusible alloy by cooling whereupon resulting expansion of the alloy produces contact pressure at an interface between the alloy and the optical fiber.
Specification