Chamfering Laser Surgical Optical Fiber

Abstract

A tool for chamfering cleaved tips of optical fibers. The tool including conical bores of relatively smooth and hard material terminate at a cylindrical bore that is slightly larger than the fiber core maximum diameter and a fiber centering bore that is slightly larger than the fiber coating maximum diameter. The tool provided such that when a cleaved fiber tip is inserted into the centering bore the sharp edge falls upon the chamfer that, when rotated relative to the fiber, gently grinds the edge to the chamfer angle. Chamfering cannot occur on the core face due to the absence of tool surface at this dimension.

Claims

1. A tool for chamfering large core, multimode optical fiber comprising: a first, fiber centering bore with a diameter slightly larger than the largest fiber diameter possible at the cladding, or slightly larger than the largest fiber diameter possible primary coating diameter within the tolerance range, a second, chamfer stop bore with a diameter that is slightly larger than the largest core diameter possible for the fiber with the tolerance range and joined to the first bore by a chamfer between the different bore diameters, upon which surface the sharp edge of a cleaved fiber is ground smooth under rotation.

2. The tool of claim one where the chamfer surface between bore diameters is a ceramic material that is harder than the fiber cladding material.

3. A chamfering tool comprising: a chamfering body defining a bore that is centrosymmetric about a longitudinal axis; the bore including an centering section adjacent to a chamfer section which is adjacent to an outflow section; the centering section including a centering surface and a centering diameter; the chamfer section including a chamfer surface and a chamfer angle; the outflow section including an outflow surface and an outflow diameter.

4. The tool of claim 3, wherein the chamfering body comprises alumina, aluminum, tungsten carbide, stainless steel, or titanium.

5. The tool of claim 4, wherein the chamfering body comprises alumina.

6. The tool of claim 4, wherein the chamfering body comprises aluminum and the chamfer surface comprises anodized aluminum.

7. The tool of claim 3 further comprising a bore surface that includes the centering surface, the chamfer surface, and the outflow surface; the bore surface comprising an alumina, a zirconia, a diamond, a tungsten carbide, a titanium dioxide, a boron nitride, a boron carbide, or a silicon carbide.

8. The tool of claim 3, wherein the chamfer surface comprises an alumina, a zirconia, a diamond, a tungsten carbide, a titanium dioxide, a boron nitride, a boron carbide, or a silicon carbide.

9. The tool of claim 3, wherein the chamfer surface has a surface hardness of at least 20 GPa.

10. The tool of claim 3, wherein the centering diameter is selected from about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; and about 1055 m to 1075 m for a 910 m fiber.

11. The tool of claim 3, wherein the centering surface has a roughness average (Ra) of less than about 0.025 m, about 0.05 m, about 0.75 m, about 0.1 m, about 0.15 m, or about 0.2 m.

12. The tool of claim 3, wherein the chamfer angle is about 23 to about 68, about 34 to about 56, or about 455.

13. The tool of claim 3, wherein the outflow diameter is selected from about 210 m to 220 m for a 200 m fiber; about 285 m to 295 m for a 273 m fiber; about 375 m to 385 m for a 365 m fiber; about 565 m to 575 m for a 550 m fiber; and about 945 m to 960 m for a 910 m fiber.

14. The tool of claim 3, wherein the outflow diameter is about 10 m to about 50 m greater than a nominal fiber diameter.

15. The tool of claim 3, wherein the chamfering body defines a plurality of bores that are individually centrosymmetric about longitudinal axes; each bore including an centering section adjacent to a chamfer section which is adjacent to an outflow section; each centering section including a centering surface and a centering diameter; each chamfer section including a chamfer surface and a chamfer angle; each outflow section including an outflow surface and an outflow diameter.

16. The tool of claim 15, wherein each bore has a centering diameter selected from about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; and about 1055 m to 1075 m for a 910 m fiber.

17. The tool of claim 15, wherein the plurality of bores includes a first bore and a second bore, wherein a first bore centering diameter is different from a second bore centering diameter.

18. The tool of claim 3, wherein the bore includes a plurality of regions each including a centering section adjacent to a chamfer section which is adjacent to an outflow section; wherein the outflow section of a first region is adjacent to the centering section of a second region.

19. The tool of claim 18 further comprising a reducing section adjacent to the first outflow section and the second centering section, wherein the reducing section has a first diameter that is equal to a first outflow diameter and a second diameter that is equal to the second centering section.

20. A process comprising: inserting a cleaved end of an endoscopic fiber into a bore of the chamfering tool of claim 3; contacting the cleaved end of an endoscopic fiber with the chamfer surface; and then applying a rotational motion to the endoscopic fiber and the chamfering tool, relative to each other, thereby chamfering a cladding carried on the cleaved end of the endoscopic fiber.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0010] For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawing figures wherein:

[0011] FIG. 1 depicts a modified fiber scoring wafer that incorporates an embodiment of the invention in a top view FIG. 1A with detail FIG. 1B and cross-sectional view FIG. 1C with detail FIG. 1D;

[0012] FIG. 2 depicts a preferred embodiment of a single fiber size chamfering tool designed for ease of use in intraoperative fiber tip reprocessing;

[0013] FIG. 3 is a cross-sectional side view detail of the chamfering element 10 in FIG. 2;

[0014] FIG. 4 depicts a fiber inserted into an alternative embodiment (FIG. 4A) of the chamfering element 10 in FIG. 2 where FIG. 4B provides some detail and FIG. 4C provides greater detail;

[0015] FIG. 5 depicts a scheme for construction of a low cost chamfering die such as depicted in FIG. 3, where FIG. 5A is a side view of a blank aluminum cylinder, FIG. 5B is the cylinder after precision boring, FIG. 5C is an isometric view after anodization and FIG. 5D is the completed die in partial cross-section;

[0016] FIG. 6 depicts a side view of a prior art thermally chamfered fiber FIG. 6A in comparison to a side view of the fiber FIG. 6B produced using a chamfering tool such as disclosed here, with detail FIG. 6C;

[0017] FIG. 7 depicts a side view FIG. 7A and top view FIG. 7B of a universal chamfering tool for optical fiber embodiment of the invention; and

[0018] FIG. 8 depicts a side view FIG. 8A of a chamfering tool and an expanded view FIG. 8B of the bore through the chamfering body.

[0019] While specific embodiments are illustrated in the figures, with the understanding that the disclosure is intended to be illustrative, these embodiments are not intended to limit the invention described and illustrated herein.

DETAILED DESCRIPTION

[0020] The invention disclosed herein provides an easy to use tool for chamfering the edges of freshly cut optical fiber, incapable of extending the chamfer into the fiber core and that is compatible with multiple sterilization methods.

[0021] FIG. 1 illustrates a ceramic (e.g. alumina) wafer tool for scoring and chamfering laser surgical fibers, in this case standard fiber sizes used in laser lithotripsy The maximum core, minimum cladding, and maximum coating dimensions of standard fibers used in laser lithotripsy are detailed in Table 1, below. Herein, these dimensions are limiting for the chamfering tool. The minimum cladding thickness is not a function of the minimum cladding dimension and the maximum core dimension, but rather it is a function of the minimum cladding to core diameter ratio and the minimum cladding diameter. As such, the typical cladding thickness is offered for reference.

[0022] Fiber scoring wafers (aka cleaving tiles) are ubiquitous in the laser surgical marketplace. Logo marked wafers are often used as promotional items at tradeshows and symposia. FIG. 1 illustrates a two inch scoring wafer that is marked with a company logo, product name and slogan as well as a metric rule as a convenient reference in tip preparation. The depicted scoring wafer includes five chamfering holes 100 which correspond to each of five standard (nominal) fiber sizes: 200, 273, 365, 550 and 910.

TABLE-US-00001 TABLE 1 Critical Fiber Dimensions (millimeters) Fiber Fiber Fiber Clad Core Max Cladding Min Coating Max Thickness 0.208 0.235 0.278 0.020 0.283 0.294 0.335 0.014 0.373 0.392 0.438 0.018 0.562 0.590 0.640 0.025 0.940 0.985 1.050 0.040

[0023] FIG. 1A illustrates a possible location of the chamfering holes 100 on the wafer 110 with FIG. 1B providing a detail view of the holes with hole size identifiers: 200, 273, 365, 550 and 910. FIG. 10 provides a reference for the cross-section hole detail drawing FIG. 1D where the hole sizes are again identified as 200 for the 200 m fiber hole, 273 for the 273 m fiber hole, 365 for the 365 m fiber hole, 550 for the 550 m fiber hole and 910 for the 910 m fiber hole.

[0024] The most challenging fiber dimension for chamfering is the 273 m core; it has the thinnest cladding at 14 m, so this hole is chosen for illustrative dimensioning. The chamfer stop bore 290 for the 273 m core fiber is approximately 285 m to 290 m or slightly larger than the largest possible fiber core that is produced within standard manufacturing tolerances. The fiber centering bore 345 for the 273 m fiber is approximately 340 m to 345 m in diameter or slightly larger than the fiber coating diameter. The two bore diameters are joined by a 30 to 120 included angle chamfering surface.

[0025] Partial rotation, reverse and repeat can be sufficient to chamfer the fiber in the operating room but such a chamfering wafer may find more utility in interoperative reprocessing where fibers may be easily rotated relative to a stationary wafer. Intraoperative reprocessing with the wafer 100 depicted in FIG. 1 may prove more difficult because fibers are typically attached to the laser console at one end and resist rotation. For intraoperative fiber reprocessing, a chamfering tool (e.g., FIG. 2) designed for single hand operation, with a rotating ball 50 for the palm, an extension handle 40, a knurled portion 30 for finger rotation, a housing 20 and a centrosymmetric chamfering die 10 is likely preferable. The die housing 20 may be adapted for quick die swapping (e.g., 20 or a combination of 20 and 30 akin to a replaceable tip screwdriver) to accommodate different fiber sizes or separate whole tools may be provided.

[0026] FIG. 3 shows a detailed view of a preferred embodiment of a chamfering die 90 made from anodized aluminum, with a fiber guide bore 80 leading to the precise fiber coating accommodating bore 75 and conical chamfering surface 70. The precise bore 60 is slightly larger than the maximum fiber core diameter and can collect the fine silica dust produced by the chamfering operation. The most challenging fiber size of 273 m core is illustrated where bore 60 is 285 m to 290 m or slightly larger than the largest possible fiber core that is produced within standard fiber manufacturing tolerances. The precision fiber centering bore 75 for the 273 m fiber is approximately 340 to m 345 m in diameter or slightly larger than the fiber coating diameter. The fiber guide bore 80 can be approximately 400 m in diameter.

[0027] It may be desirable to limit the length of the precision fiber centering bore 75, as illustrated, to reduce the length of fiber that may incur coating damage to that very near the fiber output surface. Approximately 0.5 mm to 1 mm of close-fitting centering bore 75 is sufficient for insuring the sharp edge of the cleaved fiber is properly positioned upon the chamfer surface 70. This length is typically burned bare of coating in production fibers, so failures due to fractures from scratching is this short section of fiber should not increase the frequency or severity over historical levels.

[0028] FIG. 4 depicts a typical jacketed laser surgical fiber 110 with a short stripped section 120 that is inserted into an alternative embodiment of a chamfering die 130 where the die 130 is a modified tungsten carbide wire drawing die with a classically filleted lead-in 140. Rather than terminate in a precision bore 160, chosen to be slightly larger than the fiber core 200, as in a standard wire drawing die, upon a second, larger bore 150 that is slightly larger than the fiber coating 170 maximum diameter, is produced within the filleted lead-in. The fiber plastic coating 170 and glass cladding 180 are depicted after being chamfered and slightly offset from the chamfering surface 190. The die 130 may be mounted within a hand tool similar to that depicted in FIG. 2.

[0029] FIG. 5 illustrates production steps for fabricating a fiber chamfering die similar to that depicted in FIG. 3 where FIG. 5A is a chamfered aluminum cylinder 210 that is roughly 5 mm in diameter and 3 mm tall. In FIG. 5B the aluminum cylinder 220 has been equipped with precisely dimensioned bores: a bore slightly larger than a 200 m fiber's core maximum dimension 230 and a bore slightly larger than the fiber coating dimensions 240 (see Table 1 for critical dimensions). A chamfer 250 joins the two bores. FIG. 5C illustrates the aluminum cylinder 260 after thin film anodization 265 (dark). FIG. 5D depicts a counterbored 270 and chamfered 275 fiber lead-in produced post anodization leaving the fiber chamfer surface 280 anodized. Boring the fiber lead-in after anodization reduces the risk of inadvertent damage being imparted to the inserted portion of the fiber not involved in centering the fiber.

[0030] FIG. 6A is a depiction of a chamfered fiber from prior art where the fiber core 300 and cladding 305 are melted by one of various means to fillet 310 the sharp edge that results from cleaving, in this case for passing through plastic tubes used in DNA/RNA cassettes or small diameter catheters. It should be noted that the filleting 310 extends through the glass cladding 305 and well into the fiber core 300. While laser filleting can be performed without extending curvature into the fiber core, maintaining a perfectly flat fiber face is relatively difficult when using thermal methods.

[0031] FIG. 6B and detail FIG. 6C reproduce the fiber tip of FIG. 4 for direct comparison to the prior art. FIG. 6B presents the fiber core 315 with glass cladding 320 with the plastic coating (ala hard polymer cladding) 325 intact but the thick polymer coating 330 stripped away. The fiber tip FIG. 6C detail shows that the chamfer 355 only affects the fiber coating 350 and glass cladding 340, leaving the fiber core 335 with the flat, snap-cut face.

[0032] FIG. 7 illustrates a universal chamfering tool embodiment where smaller fibers pass freely through the chamfering tool segments for larger fibers. For orientation, the insertion side 33 is up or out of the page in the top view of FIG. 7B and up is to the right in FIG. 7A, the view from the side 99 of the universal die. A 200 m core fiber would pass down through the 910 m fiber centering bore 91 and the 910 m fiber chamfering surface 91immediately below, through the 910 m fiber chamfer stop bore 94 and associated non-tool chamfer 84, into the 550 m fiber centering bore 55 and the 550 m fiber chamfering surface 55 immediately below, into the 550 m fiber chamfer stop bore 54 and associated non-tool chamfer 44, into the 365 m fiber centering bore 36 and the 365 m fiber chamfering surface 36 immediately below, into the 273 m centering bore 27 that serves a dual role as the 365 m fiber stop bore and through the 273 m fiber chamfering surface 27 immediately below that, and finally into the 200 m fiber centering bore 2 that serves a dual role as the 273 m fiber stop bore, it's 200 m fiber chamfering surface 2 and the 200 m fiber stop bore 1.

[0033] FIG. 8 illustrates another embodiment having a conical procession leading to a first centering section. In one example, the chamfering tool includes a chamfering body 1 defining a bore 2 that is centrosymmetric about a longitudinal axis 3. The bore 2 can include a centering section 4 adjacent to a chamfer section 5 which is adjacent to an outflow section 6. Notably, the centering section 4 can include a centering surface 7 and a centering diameter 8. The chamfer section 5 including a chamfer surface 9 and a chamfer angle 10. Where the chamfer angle is the deflection from the longitudinal axis 3. The outflow section 6 includes an outflow surface 11 and an outflow diameter 12.

[0034] In one instance, the chamfering body 1 is composed of or includes alumina, aluminum, tungsten carbide, stainless steel, or titanium. In one preferable example, the chamfering body comprises alumina. In another preferable example, the chamfering body 1 comprises aluminum and the chamfer surface 9 comprises anodized aluminum. In another instance, the chamfering body 1 can be held within a support composed of the same or different composition as the chamfering body (see e.g., FIG. 2).

[0035] In another instance, the chamfering tool includes a bore surface that includes the centering surface 7, the chamfer surface 9, and the outflow surface 11. In one example, the bore surface can be composed of an alumina, a zirconia, a diamond, a tungsten carbide, a titanium dioxide, a boron nitride, a boron carbide, or a silicon carbide. In another example, the bore surface is composed of a material with hardness greater than the hardness of the fiber core. In one preferable example, the chamfer surface 9 is composed of an alumina, a zirconia, a diamond, a tungsten carbide, a titanium dioxide, a boron nitride, a boron carbide, or a silicon carbide. In another preferable example, the chamfer surface 9 has a surface hardness of at least 20 GPa. In yet another preferable example, the centering surface 7 can have a roughness average (Ra) of less than about 0.025 m, about 0.05 m, about 0.75 m, about 0.1 m, about 0.15 m, or about 0.2 m; preferably less than about 0.025 m, about 0.05 m, about 0.75 m, or about 0.1 m. In still another preferable example, the chamfer surface 9 has a roughness average that is greater than the centering surface 7 roughness on average.

[0036] In another instance, the centering diameter is selected to correspond to the nominal diameter of an optical fiber. The five standard optical fibers have nominal diameters of 200, 273, 365, 550 and 910 m. In one example, the centering diameter can be about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; or about 1055 m to 1075 m for a 910 m fiber. In an example wherein the chamfering tool includes a plurality of bores (e.g., FIG. 1), the centering diameters can be have the same or different centering diameters, each selected from about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; and about 1055 m to 1075 m for a 910 m fiber.

[0037] In another example, the chamfering tool can include a single bore that can be utilized to chamfer fibers of differing diameter (e.g., FIG. 7), the bore may include at least two centering diameters selected from about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; and about 1055 m to 1075 m for a 910 m fiber. In one instance, the chamfering body defines a plurality of bores that are individually centrosymmetric about longitudinal axes; each bore including an centering section (e.g., 36) adjacent to a chamfer section (e.g., 36) which is adjacent to an outflow section (e.g., 27); each centering section including a centering surface and a centering diameter; each chamfer section including a chamfer surface and a chamfer angle; each outflow section including an outflow surface and an outflow diameter. In this instance, each bore can have a centering diameter selected from about 285 m to 295 m for a 200 m fiber; about 340 m to 350 m for a 273 m fiber; about 445 m to 455 m for a 365 m fiber; about 645 m to 655 m for a 550 m fiber; and about 1055 m to 1075 m for a 910 m fiber. By way of example, FIG. 7A depicts a chamfering tool having a single bore with a plurality of axially symmetric chamfering regions/sections. In one example, chamfering regions can overlap; for example, the tool can include a first region and a second region, for example for a 200 m fiber and a 273 m fiber, respectively. In this example, the first region includes an outflow section 2, a chamfer surface 27, and a centering section 27; the second region includes an outflow section 27 which overlaps with or is identical to the first region's centering section, a chamfer surface 36, and a centering section 36. In another example, the chamfering regions can be separated by a reducing chamfer; for example, the first region includes an outflow section 54, a chamfer surface 55, and a centering section 55; the second region includes an outflow section 94, a chamfer surface 91, and a centering section 91. These two regions are separated by a reducing chamfer 84. In still another example, the tool can include a plurality of regions wherein first and second regions have centering and outflow regions that overlap and wherein a third region is divided from another region (e.g., the second region or a fourth region) by a reducing chamfer.

[0038] In another instance, the chamfer angle is about 23 to about 68, preferably about 34 to about 56, In a preferable instance, the chamfer angle is about 455.

[0039] In yet another instance, the outflow section can include an outflow diameter that is approximately equal to or slightly larger than the nominal fiber diameter. In one example, the outflow diameter can be selected from about 210 m to 220 m for a 200 m fiber; about 285 m to 295 m for a 273 m fiber; about 375 m to 385 m for a 365 m fiber; about 565 m to 575 m for a 550 m fiber; and about 945 m to 960 m for a 910 m fiber. In another example, the outflow diameter is about 10 m to about 50 m greater than a nominal fiber diameter, preferably, about 10 m to about 35 m greater than a nominal fiber diameter.

[0040] Yet another embodiment is a process of using the above described chamfering tool to provide a chamfer on a cleaved optical fiber. The process can include providing the chamfering tool, and rotating the fiber or chamfering tool in relation to the other, thereby chamfering the cleaved surface of the optical fiber.