Optical fiber connector structure

• US 4,887,880 A
• Filed: 08/31/1988
• Issued: 12/19/1989
• Est. Priority Date: 08/31/1988
• Status: Expired due to Fees

• Current Assignee: Raynet Corp. (Raychem Corporation)
• Original Assignee: Raynet Corp. (Raychem Corporation)
• Inventors: Levinson, Frank H.
• Primary Examiner(s): FONT, FRANK G
• Application Number:
  US07/239,170
• Time in Patent Office: 475 Days
• Field of Search: 350/96.15, 350/96.16, 350/96.29, 350/96.30, 350/96.33, 350/96.34
• US Class Current: 385/48
• CPC Class Codes: G02B 6/02033 Core or cladding made from organic material, e.g. polymeric material G02B1/04 takes precedence
• CPC Class Codes: G02B 6/2552 reshaping or reforming of light guides for coupling using thermal heating, e.g. tapering, forming of a lens on light guide ends
• CPC Class Codes: G02B 6/2804 forming multipart couplers without wavelength selective elements, e.g. "T" couplers, star couplers
• CPC Class Codes: G02B 6/2808 using a mixing element which evenly distributes an input signal over a number of outputs
• CPC Class Codes: H04B 10/2581 Multimode transmission

Abstract

An optical fiber tap for connecting polymer optical fibers is achieved by heating an end section of the fibers to be connected and deforming the end sections into a non-circular cross-sectional shape so as to form a throughput cross-sectional area and a add/drop throughput area, the optical fiber ends being thereafter aligned so as to allow for efficient signal extraction and injection.

Claims

1. An apparatus for tapping an optical fiber, comprising:

an elongated first optical fiber having a noncircular end which has an end cross-section taken along a plane perpendicular to a longitudinal axis of the fiber which includes a throughput area and a light-add/light-drop area, a core of the throughput area being integral with a core of the light-add/light-drop area, the light-add/light-drop area and throughput area being enveloped by a common cladding;

an elongated second optical fiber having an end which has an end cross-section optically coupled to the first optical fiber end throughput area;

optical path means optically interconnecting the light-add/light-drop area and at least one of an electro-optic transducer and a sensor.

2. The apparatus of claim 1, the first optical fiber comprising a multimode optical fiber.

3. The apparatus of claim 1, the optical path means including a waveguide optically interconnecting the light-add/light-drop area and the at least one of the transducer and sensor.

4. The apparatus of claim 1, the second optical fiber end being non-circular, the end cross-section of the second optical fiber including a throughput area and an light-add/light-drop area, the throughput area of the first and second fibers being optically interconnected while the light-add/light-drop areas are maintained out of phase.

5. The apparatus of claim 4, further comprising at least one of a second electro-optic transducer and a second sensor optically coupled to the second fiber light-add/light-drop area.

6. The apparatus of claim 1, the first and second fiber ends each including a polymer core surrounded by a polymer cladding.

7. The apparatus of claim 1, the first and second optical fiber throughput areas being shaped, sized and arranged so as to induce an attenuation to an optical signal propagating therebetween which is less than 1.0 dB.

8. The apparatus of claim 1, the first and second optical fiber throughput areas being shaped, sized and arranged so as to induce an attenuation to an optical signal propagating therebetween which is between 5 and 12 dB.

9. The apparatus of claim 1, the first optical fiber end being part of a first optical fiber and the second optical fiber end being part of a second optical fiber, the first and second optical fibers having substantially uniform noncircular cross-sections throughout their length.

10. The apparatus of claim 1, the first optical fiber end being part of a first optical fiber and the second optical fiber end being part of a second optical fiber, the first and second optical fibers having substantially uniform circular cross-sections in sections adjacent the first and second fiber ends.

11. The apparatus of claim 1, the optical path means optically interconnecting the light-add/light-drop area at a sensor, the sensor being arranged so as to modulate light withdrawn from the light-add/light-drop area and then reinjecting the modulated light into the light-add/light-drop area.

12. A method of tapping an optical fiber comprising the steps of:

deforming an end section of a first preformed optical fiber from a first cross-sectional profile to a connectable second cross-sectional profile, the second profile being non-circular and including a throughput area and an light-add/light/drop area;

optically connecting the throughput area to a second optical fiber end;

optically connecting at least one of an electro-optic transducer and a sensor to the light-add/light-drop area.

13. The method of claim 12, the first optical fiber end section including a polymer core and a polymer cladding.

14. The method of claim 13, the first optical fiber end section being deformed by being heated to a softening temperature thereof and by applying pressure to the first optical fiber end section while in its softened state.

15. The method of claim 14, the first optical fiber having a substantially circular profile at a section thereof adjacent its deformed end, the end section being substantially circular prior to being deformed.

16. The method of claim 14, the second optical fiber including a polymer core and a polymer cladding, the second optical fiber end being deformed by being heated to a softening temperature thereof and by applying pressure to the second optical fiber section while in its softened state.

17. The method of claim 12, the end section of the optical fiber being deformed such that a dimensional tolerance of the throughput area is controlled so as to be within a predefined narrow range, the light-add/light-drop area having an uncontrolled variable size which is dependent on an amount of deviation of an undeformed cross-sectional size of the first optical fiber end section from a desired size.

18. A method of deforming an end section of a first preferred optical fiber from a first cross-sectional profile to a connectable second cross-sectional profile, comprising the steps of:

disposing the end section within a cavity having a cross-sectional profile similar to the first cross-sectional profile, the cavity being surrounded by an unstable memory material and being formed thereby;

heating the memory material to a temperature sufficient to cause it to dimensionally deform to a cross-sectional profile similar to the second profile.

19. The method of claim 18, the memory material comprising a metal.

20. The method of claim 18, the second profile being non-circular and including a throughput area and an light-add/light-drop area.