US4978377A
Expired / Lapsed
US
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Method of assembling a fiber optic preform from discrete preformed elements
Assignee: Alcatel Lucent NV
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Filing: 1989-12-07
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Granted: 1990-12-18
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Expires: 2009-12-07
Abstract
Abstract A method of providing a preform for a polarization-maintaining optical fiber, starting from a basic preform (1) having two orthogonal planes of symmetry intersecting along its axis, and mechanically applying two discrete preformed oblong elements (15) of silica doped with boron oxide on the outside face of said basic preform symmetrically about the first plane (20), and two oblong elements of silica doped with titanium oxide on the outside face of said basic preform and symmetrically about the second plane (30). The shapes of the basic preform and the four oblong elements are selected to define a substantially solid cylinder.
Inventors
- 👤 Claude Brehm
- 👤 Josiane Ramos
- 👤 Philippe Dupont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 11:51
CPC Classifications
C; C03; C03B; C03B37/00; C03B37/01; C03B37/012; C03B37/014; C03B37/018; C03B37/01861; C03B37/01205; C03B37/01211; C03B37/01217; C03B37/01225; C03B37/01228; C03B37/01231; C03B2203/00; C03B2203/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
208 words
A method of assembling a preform for a polarization-maintaining optical fiber, comprising the steps of providing a basic monomode preform comprising a solid elongated silica core of circular cross section surrounded by a solid silica cladding, said basic preform having a longitudinal axis intersected by two orthogonal planes of symmetry, attaching on the outside face of said basic preform a first pair of discrete preformed elongated stress elements each consisting essentially of silica doped with boron oxide, said first pair of elongated stress elements being disposed symmetrically about one of said planes and parallel to said axis, attaching on the outside face of said basic preform a second pair of discrete preformed elongated stress elements each consisting essentially of silica doped with titanium oxide said second pair of elongated stress elements being disposed symmetrically about the other of said planes and parallel to said axis, wherein said basic preform, said first pair of elongated stress elements, and said second pair of elongated stress elements complement one another in cross section so as to form a substantially solid cylinder of circular cross section, consisting of the basic preform and two pairs of elongated stress elements, when the two pairs of elongated stress elements are attached to the basic preform.
Claim 2
Independent Claim
208 words
A method of assembling a preform for a polarization-maintaining optical fiber, comprising the steps of providing a basic monomode preform comprising a solid elongated silica core of circular cross section surrounded by a solid silica cladding, said basic preform having a longitudinal axis intersected by two orthogonal planes of symmetry, attaching on the outside face of said basic preform a first pair of discrete preformed elongated stress elements each consisting essentially of silica doped with boron oxide, said first pair of elongated stress elements being disposed symmetrically about one of said planes and parallel to said axis, attaching on the outside face of said basic preform a second pair of discrete preformed elongated stress elements each consisting essentially of silica doped with titanium oxide said second pair of elongated stress elements being disposed symmetrically about the other of said planes and parallel to said axis, wherein said basic preform, said first pair of elongated stress elements, and said second pair of elongated stress elements complement one another in cross section so as to form a substantially solid cylinder of circular cross section, consisting of the basic preform and two pairs of elongated stress elements, when the two pairs of elongated stress elements are attached to the basic preform.
Claim 3
Dependent Claim
35 words
A method according to claim 1, wherein said basic preform has a cylindrical outside face and each elongated element is a portion of a circular tube cut along two planes intersecting along the tube axis.
Claim 4
Dependent Claim
43 words
A method according to claim 2, wherein said tube is a support tube provide on its inside with a deposit of silica doped either with boron oxide or with titanium oxide, said tube subsequently being cut longitudinally by means of a diamond saw.
Claim 5
Dependent Claim
58 words
A method according to claim 1, wherein said basic preform has a prismatic outside face and said pairs of elongated elements are obtained by collapsing tubes of pure silica internally doped with either boron oxide or titanium oxide, with the pure silica portion subsequently being machined or polished laterally so as to form a prism of polygonal section.
Claim 6
Dependent Claim
15 words
A method according to claim 4, wherein the cross-section of said basic preform is square.
Claim 7
Dependent Claim
47 words
A method according to claim 1, wherein said basic preform is an initially circular cylindrical basic preform which has been machined so as to form two pairs of grooves in its outside surface for receiving respective pairs of said elongated stress elements which consist of cylindrical blanks.
Claim 8
Dependent Claim
53 words
A method according to claim 6, wherein the cylindrical blanks are formed from a boron oxide blank or a titanium oxide blank which is formed by collapsing a support tube containing internal deposits of silica doped either with boron oxide or with titanium oxide, and then totally or partially eliminating said support tube.
Claim 9
Dependent Claim
34 words
A method according to claim 1, wherein the assembly defined by said basic preform and said four elongated stress elements is inserted into an outer silica tube and the whole assembly is then collapsed.
Claim 10
Dependent Claim
17 words
A method according to claim 1, wherein the silica doped with boron oxide further includes germanium oxide.
Claim 11
Dependent Claim
17 words
A method according to claim 1, wherein the silica doped with titanium oxide further includes fluorine doping.
References Cited (Backward Citations)
US4105283A
Cited
GB2012983A
Cited
US4360371A
Cited
US4415230A
Cited
US4395270A
Cited
US4478489A
Cited
DE3417560A1
Cited
US4561871A
Cited
US4549891A
Cited
US4681399A
Cited
JPS61228404A
Cited
JPS61267707A
Cited
JPS628105A
Cited
GB2180232A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-17 | 1994-06-18 | 1994-12-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-17 | 1998-06-18 | 1998-12-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-17 | 2002-06-18 | 2002-12-18 | $7700.00 | Window Closed / Lapsed |