Loop back plug and method

• US 20060257092A1
• Filed: 04/19/2006
• Published: 11/16/2006
• Est. Priority Date: 04/19/2005
• Status: Active Grant

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Reagan, Randy, Lu, Yu, Noonan, Michael, Gniadek, Jeff
• Granted Patent: US 7,565,055 B2
• Time in Patent Office: Days
• US Class Current: 385/134
• CPC Class Codes: G01M 11/33 with a light emitter being disposed at one fibre or waveguide end-face, and a light receiver at the other end-face
• CPC Class Codes: G02B 6/3823 containing surplus lengths, internal fibre loops provisionally see also G02B6/444
• CPC Class Codes: G02B 6/3827 Wrap-back connectors, i.e. containing a fibre having an U shape
• CPC Class Codes: G02B 6/3849 using mechanical protective elements, e.g. caps, hoods, sealing membranes G02B6/3816 takes precedence; provisionally see H01R13/44
• CPC Class Codes: G02B 6/385 Accessories for testing or observation of connectors means for centering or aligning the light guide within the ferrule with auxiliary facilities for movably aligning or adjusting the fibre within its ferrule, measuring position, eccentricity G02B6/3843; mechanical features associated with the optical testing of optical fibres G01M11/088
• CPC Class Codes: G02B 6/3878 comprising a plurality of ferrules, branching and break-out means
• CPC Class Codes: G02B 6/3885 Multicore or multichannel optical connectors, i.e. one single ferrule containing more than one fibre, e.g. ribbon type optical ribbon cable G02B6/4403, G02B6/448
• CPC Class Codes: G02B 6/3895 identification of connection, e.g. right plug to the right socket or full engagement of the mating parts keying element on the plug or adapter G02B6/3831; keying element on the ferrule G02B6/3851; keying element for electrical connection H01R13/64
• CPC Class Codes: G02B 6/3897 Connectors fixed to housings, casing, frames or circuit boards G02B6/44528 takes precedence
• CPC Class Codes: G02B 6/4472 Manifolds
• CPC Class Codes: G02B 6/4473 Three-way systems
• CPC Class Codes: G02B 6/4475 with provision for lateral branching G02B6/4431 takes precedence
• CPC Class Codes: G02B 6/562 locatable, e.g. using magnetic means

Abstract

A loop back connector and methods for testing lines in a fiber optic network are disclosed. The loop back connector includes a ferrule having an interface side constructed for optical connection to a multifiber optical cable. The loop back connector also includes first and second optical loop back paths, each having first and second terminal ends positioned at the interface side. The terminal ends of each loop back path are adapted to be aligned to fibers in the multifiber optical cable. The method includes injecting a signal on a first optical path at a first location, looping back the signal at a second location onto a second optical path, and receiving the signal on the second optical path at the first location.

Claims

1. A loop back connector comprising:

(a) a ferrule structure having an interface side constructed for optical connection to a multifiber optical connector;

(b) a first optical loop back path having first and second terminal ends positioned at the interface side, the first terminal end adapted to be aligned to a first fiber in the multifiber optical connector and the second terminal end adapted to be aligned to a second fiber in the multifiber optical connector; and

(c) a second optical loop back path having first and second terminal ends positioned at the interface side, the first terminal end configured to couple to a third fiber in the multifiber optical connector and the second terminal end configured to couple to a fourth fiber in the multifiber optical connector.

2. The loop back connector of claim 1, wherein the first and second optical loop back paths are formed in a planar lightwave circuit.

3. The loop back connector of claim 2, wherein the planar lightwave circuit is incorporated into the ferrule structure.

4. The loop back connector of claim 3, wherein the planar lightwave circuit floats within a receptacle of the ferrule structure.

5. The loop back connector of claim 4, wherein the planar lightwave circuit comprises a glass substrate etched to form first and second waveguides corresponding to the first and second optical loop back paths.

6. The loop back connector of claim 1, wherein a predetermined insertion loss is fabricated into at least one of the first and second optical loop back paths.

7. The loop back connector of claim 6, wherein the predetermined insertion loss is wavelength-sensitive.

8. The loop back connector of claim 6, wherein the first and second optical loop back paths have a consistent insertion loss.

9. The loop back connector of claim 4, further comprising a retaining structure constructed to retain the planar lightwave circuit within the receptacle of the ferrule structure.

10. The loop back connector of claim 1, further comprising alignment features constructed to complement alignment features of the connector.

11. A method of testing lines in a fiber optic network, the method comprising:

injecting a signal on a first optical path at a first location;

looping back the signal at a second location by using a loop-back path of a planar lightwave circuit to loop the signal from the first optical path to a second optical path;

receiving the signal at the first location on the second optical path.

12. The method of claim 11, further comprising testing the signal received at the first location for signal degradation.

13. The method of claim 11, wherein the planar lightwave circuit is connected to the fiber optic network at the time the first and second optical paths are installed.

14. The method of claim 11, wherein the first location is a central office.

15. The method of claim 11, wherein the second end is a factory-integrated termination location.

16. A method of testing lines in a fiber optic network, the method comprising:

injecting a signal on a first optical path at a first location;

looping back the signal at a second location via a loop back connector comprising;

(a) a ferrule having an interface side constructed for optical connection to a multifiber optical cable having a plurality of optical paths including the first optical path and the second optical path;

(b) a first optical loop back path having first and second terminal ends positioned at the interface side, the first terminal end adapted to be aligned to the first optical path and the second terminal end adapted to be aligned to the second optical path;

(c) a second optical loop back path having first and second terminal ends positioned at the interface side, the first terminal end configured to couple to a third optical path and the second terminal end configured to couple to a fourth optical path;

receiving the signal at the first location on the second optical path.

17. The method of claim 16, wherein the loop back connector is connected to a multifiber connector positioned at a breakout location of a distribution cable.