Loopback device utilizing bend insensitive optical fiber

• US 7,596,293 B2
• Filed: 01/28/2008
• Issued: 09/29/2009
• Est. Priority Date: 04/18/2006
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Cable Systems LLC (Corning Incorporated)
• Inventors: Tran, Hieu V., Luther, James P., Theuerkorn, Thomas, Lewallen, Christopher P., Isenhour, Micah C.
• Primary Examiner(s): Doan; Jennifer
• Application Number:
  US12/011,508
• Publication Number:
  US 20080131056A1
• Time in Patent Office: 610 Days
• Field of Search: 385/134, 385/135, 385/136, 385/137
• US Class Current: 385/134
• CPC Class Codes: G02B 6/4475 with provision for lateral branching G02B6/4431 takes precedence
• CPC Class Codes: G02B 6/545 Pulling eyes G02B6/475 takes precedence

Abstract

A loopback device utilizing bend insensitive optical fiber to facilitate deployment of a connectorized fiber optic distribution cable through small-diameter conduit. A loopback device utilizing bend insensitive optical fiber for use within an optical network to route optical signals transmitted downstream along one or more optical fibers back upstream along the same or other optical fibers for the purpose of the determining the integrity of the downstream and upstream optical paths from a single upstream location. A loopback device including one or more bend insensitive optical fibers, a multi-fiber loopback ferrule and a dust cap for sealing engaging a connector plug attached to a distribution cable or a tether of a pre-engineered distribution cable assembly prior to installation of the distribution cable.

Claims

1. A loopback device utilizing bend insensitive optical fiber for routing an optical signal transmitted from an upstream location along at least one optical fiber back to the upstream location along at least one other optical fiber terminated to a common multi-fiber connector, the loopback device comprising:

one or more bend insensitive optical fibers;

a loopback multi-fiber ferrule for receiving end portions of the one or more bend insensitive optical fibers;

housing means for protecting the one or more bend insensitive optical fibers within the loopback device and for sealingly engaging the common multi-fiber connector, wherein the loopback device is sized to fit through a conduit having an inner diameter of less than about 1.25 inches.

2. The loopback device according to claim 1, wherein the loopback device is attached to a fiber optic cable.

3. The loopback device according to claim 1, wherein each of the one or more bend insensitive optical fibers has a first end portion and a second end portion mounted within the loopback multi-fiber ferrule, and wherein the common multi-fiber connector comprises a multi-fiber ferrule configured for optical connection with the loopback multi-fiber ferrule.

4. The loopback device according to claim 1, wherein the one or more bend insensitive optical fibers are capable of maintaining bend related losses below about 0.5 dB at about 1300 nm for about a 12.0 mm bend through about 180 degrees.

5. The loopback device according to claim 1, wherein the loopback device provides a continuous loop for interconnecting lengths of optical fibers.

6. The loophack device according to claim 1, wherein degradation of a fiber array terminated to a multi-fiber ferrule of the common multi-fiber connector is avoided using at least one of a desiccant pill, a reduced spring force, a reduced strength adhesive, or an air gap between.

10. The loopback device according to claim 1, further including a pulling grip.

7. A connectorized fiber optic distribution cable assembly including at least one mid-span access location at which one or more optical fibers branched from the distribution cable are terminated to a multi-fiber connector optically connected to a loopback device utilizing bend insensitive optical fiber, the loopback device comprising:

one or more bend insensitive optical fibers;

a loopback multi-fiber ferrule;

a loopback inner assembly for receiving and aligning the loopback multi-fiber ferrule; and

a dust cap for sealingly engaging the multi-fiber connector of the distribution cable assembly;

the loopback device being operable for transmitting an optical signal from an upstream location along one or more of the branched optical fibers through the loopback device and back to the upstream location along the one or more branched optical fibers, wherein the loopback device is sized for installation with a distribution cable assembly through a conduit having an inner diameter of less than about 1.25 inches.

8. The connectorized fiber optic distribution cable assembly according to claim 7, wherein the one or more bend insensitive optical fibers are capable of maintaining bend related losses below about 0.5 dB at about 1300 nm for about a 12.0 mm bend through about 180 degrees.

9. The connectorized fiber optic distribution cable assembly according to claim 7, wherein the loopback device is installed on a pre-engineered fiber optic distribution cable assembly prior to installation of the distribution cable assembly.

11. The connectorized fiber optic distribution cable assembly according to claim 7, the loopback device having a pulling grip.