US 7,103,257 B2 · Hermetically sealed fiber tail assembly for polarization maintaining fiber

Abstract

A fiber tail assembly is provided that includes an outer sleeve, which can be attached and hermetically sealed to the housing of an optical device, and a sealing ferrule, which may be inserted into and hermetically sealed to the outer sleeve. An optical fiber may be inserted through an axial bore in the sealing ferrule and hermetically sealed thereto, such as with a glass seal. The hermetic seal between the sealing ferrule and the fiber avoids high or transversely asymmetric stress that may change the birefringence of the fiber. The optical fiber may be inserted through a cap ferrule or a stress relief tube, which may be attached to the fiber and to the outer sleeve, protecting the fiber tail assembly from axial stress that may damage the fiber or the hermetic seals. Methods for forming the same are provided.

Claims22

Dependent claims

A fiber tail assembly for connecting an optical fiber to an optical device, comprising:

an outer sleeve having a front end for connection to an optical device and a back end;
a sealing ferrule located in the outer sleeve, the sealing ferrule including a substantially axial bore;
a ferrule seal for hermetically sealing the sealing ferrule to the outer sleeve;
an optical fiber that extends from a back end of the sealing ferrule, through the bore, and protrudes out of a front end of the sealing ferrule;
a fiber seal for hermetically sealing the optical fiber directly to the sealing ferrule;
and a cap ferrule that has a front and back end and is located in the outer sleeve at the back end of the outer sleeve, the cap ferrule having a substantially axial bore, the optical fiber passing through the bore of the cap ferrule, and the cap ferrule, the outer sleeve, and the fiber being secured together.

3 more elements

A method of providing a fiber tail assembly for connecting an optical fiber to an optical device, the method comprising:

stripping a length of optical fiber of its buffer layer so as to form a stripped length at a front end and an unstripped length behind;
inserting a front end of a sealing ferrule into a back end of an outer sleeve, the sealing ferrule having an opposite back end and a substantially axial bore;
hermetically sealing the sealing ferrule to the outer sleeve with a ferrule seal;
inserting the stripped length of optical fiber into the bore at the back end of the sealing ferrule and advancing the fiber so that a portion of the stripped length protrudes out of the front end of the sealing ferrule and a part of the unstripped length lies in the back end of the outer sleeve;
securing together the back end of the sealing ferrule, a portion of the stripped length, and the interior of the outer sleeve;
and
hermetically sealing the front end of the sealing ferrule directly to a portion of the stripped length protruding from the front end of the sealing ferrule;
and providing a cap ferrule, the cap ferrule including front and back ends and a substantially axial bore;
inserting the stripped length of optical fiber into the bore at theback end of the cap ferrule so that a front edge of the unstripped length is substantially advanced to the back end of the bore;
inserting the front end of the cap ferrule into the back end of the outer sleeve so that a part of the stripped length protrudes out of the front end of the sealing ferrule and a part of the cap ferrule protrudes out of the back end of the outer sleeve;
and securing together the cap ferrule and the outer sleeve.

8 more elements

Dependencies are inferred from the claim text.

Hermetically sealed fiber tail assembly for polarization maintaining fiber

Life of this patent

Hermetically sealed fiber tail assembly for polarization maintaining fiber

Life of this patent

Abstract

Claims22