US 6,788,873 B2 · Method of hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve with glass solder and hermetically sealed feedthrough device made thereby

Abstract

To hermetically seal a fiber optic light guide (1) in a stripped or de-coated state, I.e. the bare optical fiber (2), in a feedthrough sleeve (5) the bare optical fiber (2) is sealed together with the feedthrough sleeve (5) by composite-glass solder with local heating. To make a permanent hermetic glass seal, the feedthrough sleeve (5) is made from an Invar alloy with very low thermal expansion and the composite-glass solder is low-melting with thermal expansion properties adapted to the alloy. The composite-glass solder is molded into prefabricated half-cylinder-shaped pressed parts (7) in a press/sinter technology process, The stripped optical fiber (2) is inserted between the pressed parts (7) arranged in the feedthrough sleeve (5) and sealed by melting the pressed parts together with each other and with the stripped optical fiber and feedthrough sleeve.

Claims21

Dependent claims

A method for hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve by means of glass solder, said fiber optic light guide comprising a longitudinally extending glass fiber (2) provided with at least one protective layer or coating (3,4), said method comprising the steps of:

a) preparing a feedthrough sleeve (5) consisting of a metallic material, said metallic material comprising an Invar alloy;
b) removing said at least one protective layer or coating (3,4) from an arbitrary position on the fiber optic light guide (1) to expose said glass fiber (2);
c) preparing two half-cylinder-shaped pressed parts (7) by a process according to press/sinter technology from a low-melting composite-glass solder, said low-melting composite-glass solder having thermal expansion properties adapted to said metallic material of the feedthrough sleeve (5), the half-cylinder-shaped pressed parts (7) each having a respective axial groove (7a) with a corresponding cross-section adapted to a diameter of the exposed glass fiber (2);
d) assembling half-cylinder-shaped pressed parts (7) together with the exposed glass fiber (2) inserted in the grooves (7a) of the half-cylinder-shaped pressed parts in said arbitrary position on the fiber optic light guide;
and
e) melting the half-cylinder-shaped pressed parts (7) together with each other and with the glass fiber (2) and the feedthrough sleeve (5) by local heating.

3 more elements

A hermetically sealed feedthrough device for hermetically sealing a fiber optic light guide (1) in a feedthrough sleeve by means of glass solder, said fiber optic light guide (1) comprising a longitudinally extending glass fiber (2) provided with at least one protective layer or coating (3,4), said hermetically sealed feedthrough device comprising

a metallic feedthrough sleeve (5) consisting of a metallic material, said metallic material comprising an Invar alloy;
and
prefabricated half-cylinder-shaped pressed parts (7) consisting of low-melting composite-glass solder, said low-melting composite-glass solder having thermal expansion properties adapted to said metallic material of the metallic feedthrough sleeve (5);
wherein a portion of the fiber optic light guide (1) in an arbitrary position on the fiber optic light guide (1) is sealed between said prefabricated half-cylinder-shaped pressed parts (7) after removal of the at least one protective layer or coating (3,4) provided on said portion at the fiber optic light guide by fusion or melting of said prefabricated half-cylinder-shaped pressed parts (7) together with said glass fiber (2) and with the metallic feedthrough sleeve (5).

1 more element

A method for hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve by means of glass solder, said fiber optic light guide (1) comprising a longitudinally extending glass fiber (2) provided with at least one protective layer or coating (3,4), said method comprising the steps of:

a) preparing a feedthrough sleeve (5) consisting of a metallic material, said metallic material comprising an Invar alloy;
b) removing said at least one protective layer or coating (3, 4) from the fiber optic light guide (1) to expose said glass fiber (2);
c) making two half-cylinder-shaped pressed parts (7) by a process according to press/sinter technology from a low-melting composite-glass solder, said low-melting composite-glass solder having thermal expansion properties corresponding to those of said metallic material of the feedthrough sleeve (5), the half-cylinder-shaped pressed parts (7) each having a respective axial groove (7a) with a corresponding cross-section adapted to a diameter of the exposed glass fiber (2);
d) assembling said two half-cylinder-shaped pressed parts (7) together with the exposed glass fiber (2) inserted in the grooves (7a) of the half-cylinder-shaped pressed parts;
and
e) melting the half-cylinder-shaped pressed parts (7) together with each other and with the glass fiber (2) and with the feedthrough sleeve (5) by local heating;
wherein said composite-glass solder comprises a phosphate glass and an inert expansion-lowering filling material.

4 more elements

a) preparing a feedthrough sleeve (5) consisting of a metallic material, said metallic material comprising an Invar alloy;
b) removing said at least one protective layer or coating (3,4) from the fiber optic light guide (1) to expose said glass fiber (2);
c) making two half-cylinder-shaped pressed parts (7) by a process according to press/sinter technology from a low-melting composite-glass solder, said low-melting composition glass solder having thermal expansion properties corresponding to those of said metallic material of the feedthrough sleeve (5), the half-cylinder-shaped pressed parts (7) each having a respective axial groove (7a) with a corresponding cross-section adapted to a diameter of the exposed glass fiber (2);
d) assembling said two half-cylinder-shaped pressed parts (7) together with the exposed glass fiber (2) inserted in the grooves (7a) of the half-cylinder-shaped pressed parts;
and
e) melting the half-cylinder-shaped pressed parts (7) together with each other and with the glass fiber (2) and with the feedthrough sleeve (5) by local heating;
wherein said composite-glass solder comprises a lead-borate glass and an inert expansion-lowering filling material.

4 more elements

Dependencies are inferred from the claim text.

Method of hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve with glass solder and hermetically sealed feedthrough device made thereby

Life of this patent

Method of hermetically sealing a fiber optic light guide in a metallic feedthrough sleeve with glass solder and hermetically sealed feedthrough device made thereby

Life of this patent

Abstract

Claims21