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EP0147168A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Three port coupler

Assignee: Northrop Grumman Guidance and Electronics Co Inc
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Filing: 1984-12-19
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Granted: —
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Expires: 2004-12-19
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Abstract

Abstract This invention is a three port fiber optic coupler for coupling light between a straight fiber having a planar exposed core portion on an end thereof and a curved fiber having an exposed planar portion on the side of the curved fiber. The curved fiber is mounted in an arcuate groove in a flat surface of a substrate which has been ground and polished to expose a portion of the core of the curved fiber. The straight fiber intersects the exposed surface of the core of the curved fiber at a predetermined angle, and the end of the straight fiber is formed such that the exposed core at the end of the straight fiber has an area that matches the area of the exposed core portion of the curved fiber as closely as possible to minimize signal loss in the coupler.

Inventors

  • 👤 David Barnett Hall

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-02 14:13
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2852; G02B6/2821; G02B6/2826

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 64 words
A three port fibre optic coupler comprising a first optical fibre having a curved region and a part removed in the curved region to provide a substantially chordal surface, and a second optical fibre having a substantially elliptical end surface, the two said surfaces being connected to one another to couple light propagating in one of said first or second fibres into the other.
Claim 2
Dependent Claim 64 words
A three port fibre optic coupler comprising a first optical fibre having a curved region and a part removed in the curved region to provide a substantially chordal surface, and a second optical fibre having a substantially elliptical end surface, the two said surfaces being connected to one another to couple light propagating in one of said first or second fibres into the other.
Claim 3
Dependent Claim 21 words
A coupler as claimed in Claim 1 in which the diameter of the first fibre exceeds that of the second fibre.
Claim 4
Dependent Claim 20 words
A coupler as claimed in Claim 1 or Claim 2 in which the said surfaces are substantially equal in area.
Claim 5
Dependent Claim 23 words
A coupler as claimed in any of Claims 1 to 3 in which the said surfaces have substantially equal major and minor axes.
Claim 6
Dependent Claim 40 words
A coupler as claimed in any of the preceding claims in which the angle of approach of the axis of the second fibre to the said chordal plane is less than the grazing angle at which total internal reflection occurs.
Claim 7
Dependent Claim 58 words
A coupler as claimed in any of the preceding claims in wich the said approach angle 0 is given by the equation: when a is the radius of the first fibre, b is the radius of curvature of the first fibre in the said curved region and d is depth of the part removed from said curved region.
Claim 8
Independent Claim 81 words
A method of forming a three part fibre optic coupler comprising the steps of exposing a substantially chordal surface in a curved portion of a first optical fibre, forming a substantially elliptical end surface on a second optical fibre such that the areas of the chordal surface and elliptical surfaces are substantially equal, moutning the first and second optical fibres with their surfaces adjacent one another to cause light propagating in one of the fibres to be coupled into the other.
Claim 9
Independent Claim 81 words
A method of forming a three part fibre optic coupler comprising the steps of exposing a substantially chordal surface in a curved portion of a first optical fibre, forming a substantially elliptical end surface on a second optical fibre such that the areas of the chordal surface and elliptical surfaces are substantially equal, moutning the first and second optical fibres with their surfaces adjacent one another to cause light propagating in one of the fibres to be coupled into the other.

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