METHOD OF WELDING A PROTECTIVE STRUCTURE TO AN OPTICAL FIBER TIP

Abstract

A method of welding a protective structure to a tip of a surgical laser fiber involves inserting the optical fiber into a length of tubing, and positioning the fiber and the tubing in a rotatable fixture arranged to simultaneously rotate the fiber and tubing while laser radiation is directed through a transparent material of the tubing, so that one or both contacting surfaces of the tubing and the fiber absorb the laser radiation and heat up to weld the tubing to the fiber. The tubing may be a length of polymer material.

Claims

1. A method of attaching a protective structure to a tip of an optical fiber, comprising the steps of: positioning, in a rotatable fixture, the fiber and a length of tubing configured to serve as the protective structure; and simultaneously rotating the fiber and length of tubing while directing laser radiation through a transparent material of the length of tubing, wherein one or both of respective contacting surfaces of the tubing and the fiber is made of a material that absorbs the laser radiation and therefore heats up when the laser radiation is directed through the transparent material of the tubing to weld the tubing to the fiber and create a weld or fused area that extends circumferentially around the fiber.

2. The method of attaching a protective structure to a tip of an optical fiber as recited in claim 1, further comprising the step of monitoring heating by detecting changes in transmission and reflection of ambient lighting resulting from heat-induced changes in the optical properties of the material or materials to which the welding energy is applied.

3. The method of attaching a protective structure to a tip of an optical fiber as recited in claim 1, wherein the tubing is a length of polymer tubing.

4. Apparatus for attaching a protective structure to a tip of an optical fiber, comprising: a rotatable fixture arranged to relatively position and rotating an optical fiber and a length of tubing into which the optical fiber has been inserted; and a waveguide for directing laser radiation through a transparent material of the length of tubing so that one or both of respective contacting surfaces of the tubing and the fiber is made of a material that absorbs the laser radiation and therefore heats up when the laser radiation is directed through the transparent material of the tubing to weld the tubing to the fiber and create a weld or fused area that extends circumferentially around the fiber.

5. Apparatus as claimed in claim 4, wherein the tubing is a length of polymer tubing.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a side view of a standoff tip undergoing a welding procedure in accordance with the principles of a preferred embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Throughout the following description and drawings, like reference numbers/characters refer to like elements. It should be understood that, although specific exemplary embodiments are discussed herein there is no intent to limit the scope of present invention to such embodiments. To the contrary, it should be understood that the exemplary embodiments discussed herein are for illustrative purposes, and that modified and alternative embodiments may be implemented without departing from the scope of the present invention.

[0015] As illustrated in FIG. 1, a polymer layer 39 is stripped or removed from an end section 38 of fiber 31 to a distance that is commonly used in the industry (for example 5 mm) leaving an underlying cladding layer made of a hard polymer material such as fluoroacrylate and the glass fiber core intact. A length of radiation-transmissive polymer tubing 32 that forms a standoff tip of the type disclosed in copending PCT Publication No. WO 2017/192869 or Provisional Patent Appl. Ser. No. 62/648,108 is positioned over the stripped end section 38 and a remaining section 39 coated with a pigmented and laser absorptive polymer fiber coating. The tubing 32 and fiber 31 are held by respective fixtures 34 and 35 that permit the tubing 32 and fiber 31 to be simultaneously rotated. Fixtures 34 and 35 may, for example, consist of or include the jaws, collets, or compression fittings of a lathe or similar rotating machine, and are rotated at the same speed to prevent distortion or twisting of the tubing 32 relative to the fiber 31 during welding.

[0016] During welding, a waveguide 33 is positioned so that a laser beam 37 transmitted through the waveguide will irradiate a section of the overlapped polymer materials. The laser is then activated to heat the area 36 to be welded as the tubing and fiber are rotated. Alternatively, the laser beam may be directed at the weld point by a movable mirror, or by a lens system, or by physically moving the laser source or the parts to be welded so that the beam may be properly positioned along an axis of the fiber and tubing during welding.

[0017] Heating of the materials is monitored by monitoring transmission and reflection of ambient lighting. As the materials are heated, their optical properties change. The resulting thermal lensing effect allows the welding operator or optical sensors to visualize the temperature of the melting materials. When the materials reach a temperature sufficient to allow fusion, the laser is deactivated to enable the parts to cool. The parts may then be inspected under various lighting conditions to verify a complete weld.

[0018] Although a specific protective structure is illustrated, the fiber tip protective structures to which the method of the invention may be applied include caps, ferrules, sleeves, sheaths, standoff catheters, or any other protective structures that are placed over and fixed to the distal or treatment end a surgical laser optical fiber, for purposes that are not limited to protection of the fiber tip or scope or to any particular type of surgical applications. Accordingly, the length of tubing that forms the protective structure is not limited to a particular material, and in particular is not limited to polymers.