CN110646887A

CN110646887A - Method for removing optical fiber coating through heat

Info

Publication number: CN110646887A
Application number: CN201910897418.XA
Authority: CN
Inventors: 张海富
Original assignee: Jiangsu Kunzai New Material Technology Co Ltd
Current assignee: Jiangsu Kunzai New Material Technology Co Ltd
Priority date: 2019-09-23
Filing date: 2019-09-23
Publication date: 2020-01-03

Abstract

A method for thermally removing a coating from an optical fiber includes providing a glass fiber having a cladding and a core, and surrounding the coating (20) with a protective coating. By removing the optical fibers coated on the ends, the ends can be precisely positioned and secured to a ferrule (14) for reliable optical communication. The coating (20) can be removed by heating, with the gold being substantially thermally removed, by passing the optical fiber through the rear opening of the heated ferrule (14). In this manner, the coating is effective to remove the optical fiber from the end and insert the ferrule bore of the ferrule to determine white activation for the optical fiber connector to effectively form a ferrule assembly.

Description

Method for removing optical fiber coating through heat

Technical Field

The present invention relates to the field of optical fiber technology, and in particular, to a ferrule assembly and related assembly for thermally removing optical fiber coatings by inserting a heated ferrule to form an optical fiber connector.

Background

The present disclosure relates generally to fiber optic connectors, and more particularly to removing a polymer coating covering an optical fiber that may be used in preparing the optical fiber for attachment into a ferrule of a fiber optic connector.

The benefits of optical fibers include extremely wide bandwidth and low noise operation. Where high bandwidth is required between two interconnected locations, fiber optic cables having fiber optic connectors may be used to transfer information between these locations. Fiber optic connectors may be used to conveniently connect and disconnect fiber optic cables from an interconnection location, for example, to facilitate maintenance and upgrade.

The optical fiber connector includes a ferrule assembly having a ferrule. The ferrule serves several purposes. The ferrule includes an internal path, referred to as a ferrule bore, through which the optical fiber is supported and protected. The ferrule bore also includes an opening at an end face of the ferrule. An opening is a location where an optical core of an end of an optical fiber can be positioned in alignment with an end of another optical fiber of a complementary connector. The optical core may be as small as eight (8) microns so that the ends of the optical fibers need to be precisely aligned to establish optical connection.

Optical fibers typically include a glass fiber (e.g., cladding and optical core) surrounded by a protective polymer coating, which is removed from the end of the optical fiber before being placed within the ferrule bore of the ferrule. This is because the polymer coating does not currently have the robust mechanical properties necessary to attach to the ferrule bore to withstand the cyclic tension experienced by the fiber optic connector over time during use without displacement creep or fracture. Moreover, the glass fiber of the optical fiber is not centered within the polymer coating with sufficient precision to allow the glass fiber to be accurately positioned within the ferrule bore without removing the coating. For at least these reasons, there are a variety of methods available for removing coatings from optical fibers, including hot gas stripping, mechanical stripping, chemical stripping, and laser stripping. All of these methods have disadvantages. Hot gas stripping uses jets of heated gas (e.g., nitrogen or air) to melt and remove the coating, but typically generates a large amount of debris. The hot gas stripping process may also not completely evaporate the coating and/or may overheat the heat sensitive material immediately adjacent the fiber core.

Mechanical stripping of optical fibers involves physically removing coating material from the glass fibers with the semi-sharp edge of a stripping blade made of metal or polymer in a manner similar to mechanical stripping of metal wires. However, mechanical stripping can be problematic because the optical fibers can be damaged and a stripping blade is required that requires time-consuming inspection and replacement procedures. Chemical stripping of optical fibers uses chemicals to dissolve the coating of the glass portion of the optical fiber, but these chemicals require extensive procedures to protect the environment and safety measures to protect personnel.

Laser stripping utilizes one or more laser beams, typically using a vaporization or ablation process to strip the coating from the glass fiber because the laser energy is absorbed by the polymer coating. To remove the coating around the fiber, the laser energy must be distributed around, which generally requires increased complexity and cost. For example, complex three-dimensional mirrors may be utilized, or specialized equipment may be used to move the optical fiber relative to the laser beam.

In addition, once the coating is removed from the end of the optical fiber using any of the above methods, the optical fiber is susceptible to damage. The stripped portion of the optical fiber can be damaged simply by contact with particles that may scratch or damage the outer surface of the optical fiber from which the coating has been removed. Any coating stripping process that is performed prior to inserting the optical fiber into the ferrule must be carefully managed so that the stripped portion of the optical fiber is not damaged before being protected into the ferrule.

What is desired is a more cost effective method of preparing an end portion of an optical fiber for termination to a ferrule such that the end portion is coupled to the ferrule and to a coating on the end portion of the optical fiber. Is removed or substantially removed. The method and related apparatus should remove a portion of the coated optical fiber from the end while minimizing damage to the optical fiber. The process should also be efficient, inexpensive, and not require unsafe chemicals.

Disclosure of Invention

Embodiments disclosed herein include thermally removing fiber coatings by inserting through a heated ferrule to form a ferrule assembly and related assemblies for a fiber optic connector. The optical fiber includes a glass fiber having a cladding and a core, surrounded by a protective coating. By removing the coating from the end portion of the optical fiber, the end portion can be accurately positioned and fixed within the ferrule for reliable optical communication. The coating may be thermally removed or substantially thermally removed by inserting the optical fiber into the rear opening of the ferrule, heating the optical fiber insertion to a temperature sufficient to at least partially separate or otherwise disengage the coating from the optical fiber.

In this regard, in one embodiment, a method of terminating an optical fiber at a ferrule to create a ferrule assembly for a fiber optic connector is provided. The method includes providing a ferrule at an initial temperature, the ferrule including a trepan extending from a rear opening to a front opening. The method further includes heating the ferrule above the initial temperature with a heating device. The method further includes inserting the coated end portion of the optical fiber through the rear opening of the ferrule bore while heating the ferrule above the initial temperature to thermally remove or substantially thermally remove the coating from the coated end portion of the passed-through optical fiber. The rear of the ferrule is open. In this way, the manufacturing time is reduced compared to conventional coating removal processes, for example, a process using a stripping blade for mechanical stripping is no longer required. In some embodiments, the ferrule may be heated above an initial temperature sufficient to change the coating on the coated end of the optical fiber to a non-solid state sufficient to thermally remove or substantially thermally remove the coating.

Another example of a method of terminating an optical fiber involves providing a ferrule having a front end, a rear end, a ferrule bore extending between the front and rear ends, and an adhesive disposed in at least a portion of the ferrule. And (4) a hole. The method further includes applying energy to heat the adhesive. When the adhesive is an optical fiber, the end of the optical fiber is inserted into the ferrule bore and through the adhesive.

The end of the optical fiber includes a primary coating prior to insertion into the ferrule bore. During insertion of the end of the optical fiber by the adhesive, the heated adhesive thermally removes at least a portion of the first coating during this time. Finally, the method includes securing the optical fiber in the core-insertion hole with an adhesive.

In another embodiment, a ferrule assembly for a fiber optic connector is provided. The ferrule assembly includes a ferrule including a ferrule bore extending from a rear opening to a front opening. The ferrule assembly also includes an optical fiber coupled to the ferrule. The optical fiber includes a coated portion disposed outside the ferrule and extending to the rear opening of the ferrule. The optical fiber also includes an end portion disposed within the ferrule bore and extending from the rear opening to the front opening of the ferrule. At least twenty-five percent (25) of the outer surface of the glass portion of the end portion of the optical fiber is free of the coating. The ferrule assembly also includes a support body disposed outside and adjacent the rear opening of the ferrule.

Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described in the written description and claims hereof, as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and are intended to provide an overview or framework for understanding the nature and character of the claims.

The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments and, together with the description, serve to explain the principles and operations of the various embodiments.

Drawings

FIG. 1 is a side perspective view of a coated end portion of an optical fiber;

FIG. 2 is a side perspective view of the coated end of the optical fiber of FIG. 1;

FIG. 3 is a flow chart of an exemplary process;

fig. 4 is a sectional view along the optical axis AX of the ferrule of fig. 2;

FIG. 5 is a cross-sectional view along the optical axis Ai of the ferrule of FIG. 2;

FIG. 6 is a cross-sectional view along the optical axis Ai of the ferrule of FIG. 2;

FIG. 7 is a cross-sectional and close-up view along the optical axis AX of a ferrule-formed ferrule assembly;

fig. 8 is a cross-sectional view and a cross-sectional view along the optical axis Ai of the ferrule assembly;

FIG. 9 is a cross-sectional view orthogonal to the optical axis Ai of the coated portion of the optical fiber;

fig. 10 is a cross-sectional view parallel to the optical axis Ai of the ferrule assembly;

FIG. 11 is a flow chart of another exemplary process;

FIG. 12 is a side view of the ferrule;

fig. 13 is a flow chart of another exemplary process of terminating an optical fiber at a ferrule to create a ferrule assembly for a fiber optic connector.

Detailed Description

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein some, but not all embodiments are shown. Indeed, these concepts may be embodied in many different forms and should not be construed as limiting herein. Rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Wherever possible, the same reference numbers will be used to refer to the same components or parts.

Embodiments disclosed herein include thermally removing fiber coatings by inserting through a heated ferrule to form a ferrule assembly and related assemblies for a fiber optic connector. The optical fiber includes a glass fiber having a cladding and a core, surrounded by a protective coating. By removing the coating from the end portion of the optical fiber, the end portion can be accurately positioned and fixed within the ferrule for reliable optical communication. The coating may be thermally or substantially thermally removed by inserting the fiber into the rear opening of the ferrule, heating the fiber insertion above a temperature sufficient to change the coating to a non-solid state.

With respect to securing the end of the optical fiber within the ferrule, it has been found that the coating can be thermally removed from the end when the coating is inserted through the rear opening of the ferrule heated above a temperature sufficient to change the temperature. The coating is non-solid. The coating may be removed because the glass portion of the optical fiber must be positioned with sufficient precision to establish optical communication when forming part of the fiber optic connector. The coating surrounding the glass portion of the optical fiber is typically not sufficiently concentric with respect to the glass portion of the optical fiber to accurately determine the position of the optical core. Because the optical fiber is subjected to axial forces during connection and disconnection with other optical fibers that are part of the optical fiber, the coating is typically not strong enough to secure the end of the optical fiber against axial movement along the optical axis of the ferrule. A connector is provided. Thus, by removing the coating from the end, the optical fiber can be safely and accurately positioned to the ferrule by forming a direct abutment between the glass portion of the optical fiber and the inner surface of the ferrule. In this manner, the conventional process of removing the coating from the end of the optical fiber prior to insertion into the optical fiber may be eliminated to save time and reduce redundancy.

In this regard, the present disclosure is organized by section. First, fig. 1 will be used to introduce the concept of inserting an optical fiber into a heated ferrule to thermally remove a coating from the end of the optical fiber. Next, the flowchart in fig. 9. With respect to the relevant process details depicted in fig. 2 and 3, fig. 2 is discussed as part of an exemplary process of terminating an optical fiber at a terminus to create a terminus assembly for a fiber optic connector. Fig. 4-4 are then introduced to illustrate a fiber optic connector sub-assembly utilizing the ferrule assembly consistent with the exemplary process of fig. 3. Fig. 2. Fig. 5 will be discussed to describe another embodiment of the process of fig. 5. In fig. 2, the ferrule is heated therein using induction heating. Finally, FIG. 6 will be discussed to describe yet another embodiment of the process of FIG. 5.

In this regard, fig. 1 is a side perspective view of a coated end portion 10 ("end") of an optical fiber 12 adjacent a rear opening 24 of a ferrule 14 where the fiber is to be terminated to form a ferrule assembly 16. A portion of an optical fiber 12 of the tip 10 includes a glass portion 18 (sometimes referred to simply as an "optical fiber") surrounded by a coating 20 (also referred to as a "primary coating"). Glass portion 18 may include silica to provide efficient transmission of light through optical fiber 12, but is susceptible to damage. The coating 20 protects the optical fiber 12 on the outside of the ferrule 14. The ferrule 14 includes a ferrule bore 22 extending from a rear opening 24 to a front opening 26 of the ferrule 14.

In particular, the ferrule bore 22 may be used to precisely position and securely hold the glass portion 18 of the optical fiber 12 within an optical fiber connector (shown later in fig. 8) so that optical communication may be established. The ferrule 14 may include at least one back surface 28 to form a tapered volume 30 to guide the end 10 of the optical fiber 12 into the ferrule bore 22.

It should also be noted that the ferrule 14 of fig. 1 may be mounted thereon. Which in fig. 1 has been heated by energy 32 to a temperature sufficient to change coating 20 of end 10 of optical fiber 12 to a non-solid state. The energy 32 may heat the ferrule 14 while minimizing damage to the ferrule 14 and the optical fiber 12. For example, the energy 32 may be transferred using conductive heat transfer, radiant heat transfer, and/or convective heat transfer. In one embodiment, ferrule 14 may be heated by induction.

FIG. 1 is a side perspective view of a coated end 10 of an optical fiber 12. After the coating 20 of the end 10 of the optical fiber 12 is inserted through the rear opening 24 of the ferrule 14 with a force F, it is shown in fig. 1. As shown in fig. 12, the metal ring 12 passes through the rear opening 24 of the heated metal ring 14. As used herein, the phrase "heat removal" or "heat removal" refers to heat from ferrule 14 (and/or an adhesive disposed in ferrule 14; discussed below) that causes coating 20 to at least partially separate or otherwise become possible (but not necessary) to remove optical fiber 20 from optical fiber 12, while coating 20 becomes non-solid. In the embodiment shown in fig. 1, the coating 20 removed from the end portion 10 may be partially converted to a gas 34, oxidized and/or partially melted to form a support 36. The support 36 may provide protection against unwanted bending of the optical fiber 12 as it is extended. Beginning at the rear end 38 of the ferrule 14.

Which would not otherwise allow the fiber 12 to be secured to the ferrule 14 with the strength required to withstand the cyclic stresses experienced by the fiber optic connector. Also, with the coating 20 removed, the glass portion 18 of the end 10 of the optical fiber 12 may be more accurately positioned since the glass portion 18 of the end 10 of the optical fiber 12 may not be relative to the ferrule 14. Centered with sufficient accuracy within the coating 20. In this manner, the optical fiber 12 can be secured and precisely positioned onto the ferrule 14 to form the ferrule assembly 16 to enable reliable optical communication when assembled as part of an optical fiber connector (fig. 8). The glass portion 18 of the end 10 of the optical fiber 12 may be more accurately positioned relative to the ferrule 14 because the glass portion 18 of the end 10 of the optical fiber 12 may not be centered within the coating 20 with sufficient accuracy. In this manner, the optical fiber 12 can be secured and precisely positioned onto the ferrule 14 to form the ferrule assembly 16 to enable reliable optical communication when assembled as part of an optical fiber connector (fig. 8). The glass portion 18 of the end 10 of the optical fiber 12 may be more accurately positioned relative to the ferrule 14 because the glass portion 18 of the end 10 of the optical fiber 12 may not be centered within the coating 20 with sufficient accuracy. In this manner, the optical fiber 12 can be secured and precisely positioned onto the ferrule 14 to form the ferrule assembly 16 to enable reliable optical communication when assembled as part of an optical fiber connector (fig. 8).

Now having introduced the concept of optical fiber 12 and ferrule 14, and thermally removing coating 20 from end 10 of optical fiber 12, an exemplary process 44 (1) provides a ferrule assembly discussion of fig. 13 for a fiber optic connector. In this regard, fig. 2 is a flow chart of an exemplary process 44 (1) of providing a ferrule assembly 16 for a fiber optic connector. Process 44 (1) in fig. 4 is performed. Fig. 2 will be described using the terms and information provided above. Fig. 3 corresponds to blocks 46A (1), 46B (1), 46C (1), and 46D (1).

Fig. 3 is a sectional view along the optical axis Ai of the ferrule 14 of fig. 2. Referring to fig. 1, there is shown providing a ferrule 14 including a trepan 22 extending from a rear opening 24 to a front opening 26 at an initial temperature (block 46A (1) in fig. 2). The ferrule 14 may comprise zirconia for strength. The initial temperature may be ambient temperature, such as twenty (20) degrees celsius. The ferrule bore 22 may be formed by an inner surface 42 of the ferrule 14 extending from the rear opening 24 to the front opening 26. The diameter DFB (or width) of the ferrule bore 22 is approximately equal to the diameter DGP (or width). In one embodiment, the diameter DFB of the ferrule bore 22 may be within ten (10) nanometers of the diameter D. Gp of glass portion 18 of fiber 12. In this manner, the glass portion 18 of the end 10 may be better secured to the inner surface 42 of the ferrule 14 when the coating 20 is thermally removed or substantially thermally removed. Is removed from the glass portion 18 at the end 10 of the optical fiber 12.

Note that ferrule 14 may be provided with an adhesive 48 that is optionally inserted into ferrule bore 22. As shown in fig. 4, the adhesive 48 may be inserted into the ferrule bore 22 with a syringe 50. Adhesive 48 may be inserted through the rear opening 24 and/or the front opening 26 to be disposed in at least a portion of the ferrule bore. 22. The adhesive 48 may be, for example, an epoxy 52. In this way, the end 10 of the fiber 12 may be better secured within the ferrule 14, and thus more resistant to movement, which may cause attenuation.

As shown in fig. 2, referring to fig. 5, process 44 (1) may include heating ferrule 14 above an initial temperature with heater device 54 (block 46B (1) in fig. 2). In one embodiment, the heater device 54 may be an oven 56 that may heat the collar 14 with the energy 32. The ferrule 14 may be heated above an elevated temperature sufficient to alter the coating 20 on the coated end 10 of the optical fiber. 12 become non-solid. For example, the elevated temperature may be three hundred (300) degrees celsius, and the coating 20 may include an acrylate. The elevated temperature may thereby thermally remove or substantially thermally remove the coating 20 from the coated end 10 of the optical fiber 12 passing through the rear opening 24 of the ferrule 14.

Fig. 6 is a sectional view along the optical axis AX of the ferrule 14 of fig. 2. Referring to fig. 5, a force F is shown being applied to the coated end 10 of the optical fiber 12, thereby inserting the end 10 into the rear opening 24 of the ferrule 14 (block 46C (1) in fig. 2). The force F may be, for example, less than two (2) pounds, and may be applied manually or by an automatic actuator (not shown). In this manner, the diameter profile (or width) of the coated end portion 10 of the optical fiber 12 may be larger than the diameter d by the second bore 22 of the F ferrule, and the coating 20 of the end portion 10 may be pushed away from the end portion 10 of the optical fiber 12 to thermally remove, or substantially thermally remove, the end portion 10 as the coating 20.

Fig. 7 depicts a cross-sectional view and a close-up view along optical axis Ai of ferrule assembly 16 formed from ferrule 14 of fig. 1. Fig. 7 shows an end 10 of an optical fiber 12. The portion in fig. 7 (frame 46D (1) in fig. 2) disposed through the ferrule 14. Specifically, the coating 20 has been thermally removed or substantially thermally removed from the end 10 of the optical fiber 12. As used herein, substantially thermally removed means at least twenty-five (25) percent of the outer surface 58 of the glass. The glass portion 18 of the end 10 of the optical fiber 12 within the core-insertion hole 22 is free of the coating 20. It is also believed that over fifty (50) percent of the uncoated 20 over seventy-five (75) percent of the outer surface 58 of the glass portion 18 of the end portion 10 of the optical fiber 12 is also possible. In this manner, the glass portion 18 of the end 10 of the optical fiber 12 may be secured to the ferrule 14 within the ferrule bore 22, such as by an adhesive 48, to minimize attenuation caused by movement of the optical fiber. There are 12 in the ferrule 14.

The support 36 may be formed outside and adjacent to the rear opening 24 of the ferrule 14 when the coating 20 is removed from the end 10 of the optical fiber 12. The support 36 may include a coating 20 that may be partially converted to a gas 34, oxidized, and/or partially melted. The support 36 may at least partially occupy the tapered volume 30 formed by the at least one rear surface 28. In this manner, the support 36 may protect the optical fiber 12 from unwanted bending when the optical fiber 12 extends from the optical fiber 12. The rear end 38 of the ferrule 14.

It should be noted that unless explicitly stated otherwise, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a particular order. Thus, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular method be so recited.

Having now introduced the optical fiber 12, ferrule 14, and process 44 (1) of terminating the optical fiber 12 at the ferrule 14 to create a ferrule assembly 16 for a fiber optic connector, i.e., the optical fiber now discusses the connector sub-assembly 60, including the ferrule assembly 16 created by exemplary process 44 (1). In this regard, fig. 8 is a cross-sectional view along the optical axis AX of the ferrule assembly 16 of fig. 3. The ferrule assembly 16 includes a ferrule 14 coupled to an optical fiber 12 as part of an exemplary fiber optic connector sub-assembly 60.

Consistent with the discussion above with respect to fig. 1-3. As shown in fig. 1-3, the ferrule assembly 16 of the fiber optic connector sub-assembly 60 includes a ferrule 14, the ferrule 14 including a ferrule bore 22 extending from a rear opening 24 to a front opening 26. Ferrule assembly 16 also includes an externally disposed support 36. ferrule assembly 16 also includes a glass portion 18 of fiber 12 secured to ferrule 14. The optical fiber 12 may be secured to the ferrule 14 with an adhesive 48. The U-shaped piece of fiber 12 including the covered portion 62 of fiber 12 is disposed outside of the rear opening 24 of ferrule 14.

The characteristics of the optical fiber 12 make heat dissipation efficient. In this regard, fig. 9 is a cross-sectional view orthogonal to the optical axis Ai of the covering portion 62.

The optical fiber 12 of fig. 1 includes: referring to FIG. 8, there is shown a glass portion 18 surrounded by a coating 20, which includes at least an inner coating 20A and an outer coating 20B. The glass portion 18 will be discussed first, followed by the coating 20.

According to an exemplary embodiment, the optical fiber 12 is a glass optical fiber configured for high-speed data communication via transmission of electromagnetic radiation (e.g., light). In some such embodiments, optical fiber 12 is a germanium-doped silica glass fiber having a glass portion 18, the glass portion 18 including a glass core 64 and a glass cladding 66. The diameter Dc of the glass core 64 may be, for example, in a range. From eight (8) microns to 62.5 microns. The glass cladding 66 forms the outer surface 58 of the glass portion 18 of the optical fiber 12 and may include a diameter DGP of, for example, one hundred twenty five (125) microns.

Reference is continued to the figures. As shown in fig. 4, inner coating 20A may be a softer, more rubbery material than outer coating 20B. The inner coating 20A may extend, for example, from the glass portion 18 to a diameter Die of one hundred ninety (190) microns. In this manner, the inner coating 20A provides a buffer for the glass portion 18 of the optical fiber 12 to protect from external mechanical loads. The inner coating 20A may also thereby enable the coating 20 to be more easily removed from the glass portion 18 of the optical fiber 12. Overcoat layer 20B can comprise a different material composition than undercoat layer 20A, resulting in a harder coating. This material is more important than the inner coating 20A, which protects the optical fiber 12 from abrasion and environmental exposure. The overcoat 20B can, for example, extend from the inner coating 20A to a diameter Doc of two hundred fifty (250) microns. Inner coating 20A and outer coating 20B can comprise a polymeric material comprising an acrylate, and can be at least twenty (20) microns thick or more to protect the outer surface 58 of the glass portion 18 of the optical fiber 12. As the optical fiber 12 approaches the rear opening 24 of the ferrule 14, the coating 20 may be heated by the ferrule 14 to change the inner coating 20A to a non-solid state and/or thermally expand a portion of the inner coating. As shown in FIG. 2, overcoat 20B is pushed away from glass portion 18. Overcoat 20B is thereby detached from glass portion 18. In this manner, the coating 20 may promote efficient heat removal.

Specifically, in one non-limiting embodiment, the inner coating 20A can expand and/or boil, thereby cracking the outer coating 20B. The outer coating 20B may or may not be changed to a non-solid state by heat from the ferrule 14. The coating 20 is then pushed in as the glass portion 18 of the optical fiber 12 is pushed into the plug bore 22. The optical fiber 12 is (or stripped away) such that at least one back surface 28 of the ferrule 14 remains outside of the ferrule bore 22. In this particular non-limiting embodiment, the coating 20 can be thermally removed from the optical fiber 12.

Refer back to the figure. As shown in fig. 4, ferrule assembly 16 includes a glass portion 18 of end 10 of optical fiber 12 attached to an inner surface 42 of ferrule 14. Fig. 4 is a cross-sectional view parallel to the optical axis AX of the ferrule assembly 16 of fig. 3. Referring to FIG. 4, the end 10 of the optical fiber 12 is shown with the coating 20 thermally removed, or substantially thermally removed, consistent with the process of FIG. 3. 2. The outer surface 58 of the glass portion 18 of the optical fiber 12 may abut the inner surface 42 of the ferrule 14. Additionally, adhesive 48 may secure glass portion 18 of optical fiber 12 to the interior. In this manner, the optical fiber 12 may be secured and accurately positioned within the ferrule 14.

Other methods may be employed to prepare the ferrule assembly 16 for the fiber optic connector sub-assembly 60 to thermally remove the coating 20 of the end portion 10 of the optical fiber 12 by inserting the coated end portion 10 of the optical fiber. The fiber 12 enters the ferrule bore 22 through the heated rear opening 24 of the ferrule 14. In this regard, fig. 10 is a flow chart of another process 44 (2) that terminates the optical fiber 12 at the ferrule 14 to create a ferrule assembly 16 for the fiber optic connector sub-assembly 60. Process 44 (2) is similar to process 44 (1). ) And for the sake of clarity and brevity, only the differences are explained.

In this regard, the process 44 (2) includes blocks 46A (2) -46D (2), which may be similar to blocks 46A (1) -46D (1) of the process 44 (1). Frame 46B (2) includes inductively heating ferrule 14 with electromagnets 66 disposed around ferrule 14. The electromagnet 66 may include at least one coil 68 (1) -68 (N) disposed about the ferrule 14. The electromagnet 66 can be coupled to a current source 70 to provide alternating current to the electromagnet 66 to inductively heat the ferrule 14. Specifically, in one embodiment, the ferrule 14 may include zirconia or other material that may be inductively heated and thereby generate eddy currents. May be induced by an electromagnet 66. The resistance of the material to eddy currents results in inductive heating of the ferrule 14. The ferrule 14 may be heated to a temperature sufficient to change the coating 20 on the coated end 10 of the optical fiber 12 to a non-solid state.

Other processes may be employed to prepare the ferrule assembly 16 for the fiber optic connector sub-assembly 60 to thermally remove the coating 20 of the end portion 10 of the optical fiber 12 by inserting the coated end portion 10 of the optical fiber. The fiber 12 enters the ferrule bore 22 through the heated rear opening 24 of the ferrule 14. In this regard, fig. 12 is a flow chart of another process 44 (3) that terminates the optical fiber 12 at the ferrule 14 to create a ferrule assembly 16 for the fiber optic connector sub-assembly 60. Process 44 (3) is similar to process 44 (1) and for clarity and brevity, only the differences are explained.

In this regard, the process 44 (3) includes blocks 46A (3) -46D (3), which may be similar to blocks 46A (1) -46D (1) of the process 44 (1). The block 46B (3) includes heating the ferrule 14 by directing a laser beam 72 emitted from a laser 74 to impinge on the ferrule 14. The laser beam 72 may include a wavelength in the range of one hundred seventeen (157) nm. Nanometer to 10.6 microns and preferably efficiently absorbed by coating 20 at a wavelength of 9.3 microns.

At least some of the energy of the laser beam 72 incident on the ferrule 14 will be absorbed by the ferrule 14. In this manner, the ferrule 14 can be heated to a temperature sufficient to alter the coating 20 on the end of the coating. The portion 10 of the fiber 12 becomes non-solid. The laser 74 may be, for example, a carbon dioxide laser that emits a laser beam 72 having a wavelength of 9.3 microns. In one embodiment, laser 74 may be a DiamondTMC-20A laser manufactured by Coherent corporation of Santa Clara, Calif.

Unless expressly stated otherwise, it is in no way intended that any method set forth herein be construed as requiring that its steps be performed in a specific order. Thus, where a method claim does not actually recite an order to be followed by its steps or it is not otherwise specifically stated in the claims or descriptions that the steps are to be limited to a specific order, it is no way intended that any particular method be so recited.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Since modifications combinations, sub-combinations and variations of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and their equivalents.

Claims

1. A method of terminating an optical fiber at a ferrule to create a ferrule assembly for a fiber optic connector, the method comprising: and inserting the coated end portion of the optical fiber into the fiber optic ferrule through the rear opening of the ferrule bore while heating the ferrule above the initial temperature sufficiently above the initial temperature to remove or substantially thermally remove the coating from the coated end portion of the optical fiber passing through the rear opening.

2. The method of claim 1, wherein the coated end portion of the optical fiber is inserted through the rear opening of the ferrule bore to become non-solid to thermally remove or substantially thermally remove the coating while the ferrule is heated above the initial temperature sufficient to alter the coating on the coated end portion of the optical fiber.

3. The method of claim 1 or 2, wherein heating the ferrule comprises heating the ferrule above an initial temperature sufficient to thermally oxidize the coating.

4. The method of any of claims 1-3, wherein heating the ferrule comprises heating the ferrule to above 300 degrees Celsius.

5. The method of any of claims 1-4, wherein heating the ferrule comprises directing a laser beam emitted from a laser to be incident on the ferrule.

6. The method of claim 5, wherein heating the ferrule comprises directing a laser beam having a wavelength in a range from 157 nanometers to 10.6 micrometers.

7. The method of any of claims 1-4, wherein heating the ferrule comprises inductively heating the ferrule with an electromagnet disposed about the ferrule.

8. The method of any of claims 1-4, wherein heating the ferrule above the initial temperature comprises: heating the ferrule with an electromagnet disposed around at least a back end of the ferrule.

9. A ferrule assembly for a fiber optic connector, comprising: a ferrule including a ferrule bore extending from a rear opening to a front opening, an optical fiber secured to a ferrule, the optical fiber comprising: the coating portion is disposed outside the ferrule and extends to the rear opening of the ferrule; and an end disposed within the ferrule bore and extending from the rear opening to the front opening of the ferrule, wherein at least 25% of an outer surface of the glass portion of the end of the optical fiber is free of the coating, and a support disposed outside and adjacent to the rear opening of the ferrule, wherein the support is formed of a coating material that has been removed from the end of the optical fiber, and further wherein the coated portion of the optical fiber is adhered to the support.

10. The ferrule assembly of claim 9, further comprising an adhesive securing the end portion of the optical fiber to the ferrule.