Multi-core optical fiber for multi-point laser probe

Abstract

The present application relates to a multi-core optical fiber for a multi-point laser probe. The present disclosure relates to a multi-core fiber cable (MCF). In some embodiments, the MCF includes a plurality of cores surrounded by a cladding and a coating surrounding the cladding, wherein one or more of the plurality of cores has a refractive index greater than a refractive index of the cladding. The MCF further includes a probe including a probe tip coupled to a distal end of the MCF; and a lens at a distal end of the probe tip. In some embodiments, the lens is configured to translate a laser beam from the distal end of the MCF to produce a laser beam multi-point pattern on a target surface; and the distal end of the MCF terminates at an interface with the lens.

Description

[0001] This application is a divisional application of the invention patent application filed on December 12, 2018, with application number 201880080456.X and invention title "Multi-core optical fiber for multi-point laser probe". Technical Field

[0002] This disclosure relates to a multi-point laser probe, and more specifically to a system and method for delivering a multi-point laser beam via a surgical probe having multi-point fiber optic cables. Background Technology

[0003] Lasers are used in a wide variety of medical procedures to assist in surgery and treat a patient's anatomical structures. For example, in laser photocoagulation, laser probes are used to ablate blood vessels at various laser ablation points on the retina. Some types of laser probes ablate multiple points at once, allowing for faster and more effective photocoagulation. Some of these multi-point laser probes split a single laser beam into multiple beams displaying a laser dot pattern and deliver these beams to an array of optical fibers displaying corresponding fiber patterns. Typically, the fibers should be tightly packed so that the fiber pattern matches the laser dot pattern. Furthermore, the laser dot pattern should be precisely aligned with the fiber pattern.

[0004] Besides ablating blood vessels at the laser ablation point, the laser can also damage the rod and cone cells in the retina that provide vision, thus affecting visual acuity. Since vision is most acute in the central macula of the retina, surgeons position the laser probe to create ablation points in the peripheral retinal region. In this way, some peripheral vision can be sacrificed while preserving central vision. During the procedure, the surgeon drives the probe with a non-ablation aiming beam to illuminate the retinal area to be photocoagulated. Due to the availability of low-power red laser diodes, the aiming beam is typically a low-power red laser. Once the surgeon has positioned the laser probe to illuminate the desired retinal points, the surgeon activates the laser via a foot pedal or other means and then performs photocoagulation on the illuminated area. After ablation of the retinal points, the surgeon repositions the probe to illuminate new points with the aiming beam, activates the laser, repositions the probe, and so on, until the desired number of ablation laser points are distributed across the retina.

[0005] For diabetic retinopathy, panretinal photocoagulation (PRP) can be performed, and the number of laser photocoagulation sessions required for PRP is typically large. For example, 1,000 to 1,500 points are usually ablated. Therefore, it is readily apparent that if the laser probe is a multi-point probe capable of ablating multiple points simultaneously, the photocoagulation process will be faster (assuming sufficient laser source power). Accordingly, multi-point / multi-fiber laser probes have been developed and described in U.S. Patent Nos. 8,951,244 and 8,561,280, the entire contents of which are incorporated herein by reference.

[0006] Vitreoretinal surgery also benefits from directing illumination light onto the eye and retinal tissue. Vitreoretinal surgeons typically use laser probes to deliver the laser aiming beam and the laser treatment beam, and also use additional instruments to direct the illumination beam onto the surface of the retina to visualize the patient's anatomy. Summary of the Invention

[0007] According to one embodiment, this disclosure relates to a multi-point laser probe comprising: a probe body shaped and sized for a user to grip; a probe tip including a cannula configured for insertion into an eye; a graded-index (GRIN) lens disposed within the cannula at its distal portion; and a multi-core fiber optic cable (MCF) extending at least partially through the cannula. The MCF may include: a plurality of cores formed of germanium-doped silicon dioxide; a cladding formed of molten silicon dioxide; a coating surrounding the cladding; and a distal end disposed at an interface with the GRIN lens. The cladding may surround the plurality of cores. The refractive index of one or more of the plurality of cores may be greater than the refractive index of the cladding. A portion of the coating may be omitted from a length of the distal end of the MCF, and the GRIN lens may be configured to translate a laser beam from the distal end of the MCF to generate a multi-point pattern of laser beams on a target surface.

[0008] Another embodiment relates to a multi-point laser probe comprising an MCF (Metallic Coil Array) and a probe, the MCF including a plurality of cores surrounded by a cladding and a coating surrounding the cladding. The probe may include a probe tip coupled to a distal end of the MCF. The multi-point laser probe may also include a lens located at the distal end of the probe tip. The lens may be configured to translate a laser beam from the distal end of the MCF to generate a multi-point pattern of laser beams on a target surface. The distal end of the MCF may terminate at an interface with the lens. The refractive index of one or more of the plurality of cores may be greater than the refractive index of the cladding.

[0009] Another embodiment relates to a method for applying a multi-point laser beam pattern. The method may include: generating a laser beam using a laser source; collimating the laser beam; guiding the collimated laser beam to a diffractive optical element (DOE) configured to generate a multi-point laser beam pattern; and focusing the multi-point laser beam pattern onto an interface plane at the proximal end of an MCF. Each laser beam in the multi-point laser beam pattern may be transmitted to one of a plurality of cores of the MCF. The laser beam may propagate along the cores of the MCF. The plurality of cores may be surrounded by a cladding, and the cladding may be surrounded by a coating. The refractive index of each of the plurality of cores may be greater than the refractive index of the cladding, and a portion of the coating may be omitted from a length at the distal end of the MCF. The method may further include transmitting the multi-point laser beam pattern to the distal end of the MCF and guiding the multi-point laser beam pattern through a lens to the distal end of a surgical probe.

[0010] The various embodiments disclosed herein may include one or more of the following features. The plurality of cores may form a 2x2 array, which may be configured to match a 2x2 multi-point pattern of a diffractive optical element (DOE) from a laser system. The distal end of the MCF may abut against the GRIN lens at the interface with positive pressure. The distal end of the MCF may be separated from the GRIN lens by an air gap. A portion of the coating length may be removed from the MCF, and this length may be in the range of 0.5 mm to 5.0 mm extending proximally from the distal end of the MCF. The length of this portion of the coating removed from the MCF may be in the range of 1.0 mm to 3.0 mm extending proximally from the distal end of the MCF.

[0011] The various embodiments disclosed herein may also include one or more of the following features: A portion of the coating may be omitted from a length of the distal end of the MCF. The length of the coating omitted from the distal end of the MCF may range from 1.0 mm to 3.0 mm. The plurality of cores may form a 2x2 array configured to match a 2x2 multi-point pattern of a diffractive optical element (DOE) from a laser system. The lens may include a GRIN lens, and the distal end of the MCF may abut the GRIN lens with positive pressure. The lens may include a GRIN lens, and the distal end of the MCF may be separated from the GRIN lens by a gap. The probe tip may include a cannula configured for insertion into an eye. The distal end of the MCF and the lens may be disposed within the cannula. A portion of the coating may be omitted at the MCF, thereby improving the power manipulation characteristics of the multi-point laser probe. The lens, which may be located at the distal end of the probe tip, may include a GRIN lens. The distal end of the MCF may abut the GRIN lens with positive pressure. The distal end of the MCF can be separated from the GRIN lens through an air gap. The coating may include a polyimide coating. The plurality of cores may include germanium-doped silicon dioxide. The cladding may include fused silicon dioxide. Attached Figure Description

[0012] To gain a more thorough understanding of this technology, its features, and its advantages, please refer to the following description in conjunction with the accompanying drawings, in which:

[0013] Figure 1 An exemplary system for generating a multi-point pattern of a laser beam for delivery to a surgical subject, according to a specific embodiment of the present invention, is shown.

[0014] Figure 2 An exemplary multi-point laser probe according to a specific embodiment of the present invention is shown.

[0015] Figure 3 and Figure 4 An exemplary multi-core fiber optic cable (MCF) for use with a non-illuminated multi-point laser probe, according to a specific embodiment of the present invention, is shown.

[0016] Figure 5 An exemplary MCF for use with an illuminating multi-point laser probe, according to a specific embodiment of the invention, is shown at one end.

[0017] Figure 6 This is a detailed cross-sectional view of the distal portion of an exemplary multi-point laser probe tip according to a specific embodiment of the present invention.

[0018] Figures 7A to 7F2Various aspects of a multi-point / multi-fiber laser probe, compared to multiple aspects of an MCF laser probe, are illustrated according to specific embodiments of the invention to highlight the individual advantages and benefits of a multi-core fiber optic cable laser probe.

[0019] Figure 8 Exemplary operations performed by a surgical laser system according to a specific embodiment of the present invention are shown.

[0020] Figure 9 The distal portion of an exemplary multi-point laser probe, operable to generate a multi-point pattern of a laser beam according to a specific embodiment of the invention, is shown.

[0021] Figure 10 The distal portion of another exemplary multi-point laser probe according to a specific embodiment of the invention is shown, in which a lens with a convex end is arranged between the distal end of the MCF and the protective window.

[0022] Figure 11 This is a side view of the exposed end of an exemplary multi-point laser probe according to a specific embodiment of the present invention, showing the exposed end of the MCF aligned with a lens.

[0023] Figure 12 The exposed end of the MCF and the lens are misaligned due to the annular gap formed between the MCF and the inner wall of the cannula.

[0024] Figure 13 A ring according to a specific embodiment of the invention is shown, the ring being arranged within an annular gap formed around the inner cladding of the MCF at the exposed end of the MCF.

[0025] Figure 14 Another exemplary multi-point laser probe cannulation including countersunk holes is shown according to a particular embodiment of the present invention.

[0026] Figure 15 An exemplary multi-point laser probe according to a specific embodiment of the present invention is shown, wherein alignment of the exposed end of the MCF is provided by a reduced inner diameter of the cannula.

[0027] Figure 16 This demonstrates a potential risk of damage to the distal end of the MCF during assembly, according to a specific embodiment of the invention.

[0028] Figure 17 and Figure 18 The invention illustrates the formation of a necked portion of the cannula of an exemplary multi-point laser probe according to a specific embodiment of the invention, for maintaining alignment of the distal end of the MCF with the lens.

[0029] Figure 19An exemplary operation for generating a multi-point laser probe according to a specific embodiment of the present invention is shown. Detailed Implementation

[0030] In the following description, details are illustrated by way of example to aid understanding of the disclosed subject matter. However, it will be apparent to those skilled in the art that the disclosed embodiments are exemplary and not an exhaustive list of all possible embodiments. Therefore, it should be understood that references to the described examples are not intended to limit the scope of this disclosure. Those skilled in the art to which this disclosure pertains will, under normal circumstances, be fully capable of conceiving of any changes and further modifications to the described apparatus, instruments, and methods, as well as any further application of the principles of this disclosure. Specifically, it is fully conceivable that features, components, and / or steps described for one implementation can be combined with features, components, and / or steps described for other implementations of this disclosure.

[0031] This disclosure describes illuminated and unilluminated multi-core laser probes and systems, as well as associated methods. Figure 1 An exemplary system 100 for generating multi-point patterns of laser beams, according to certain embodiments, is shown.

[0032] System 100 includes a surgical laser system 102, which includes one or more laser sources for generating a laser beam that can be used during ophthalmic surgery. For example, the ophthalmic surgical laser system 102 may alternatively generate a surgical treatment beam having a first wavelength (e.g., about 532 nanometers (nm)) and a laser aiming beam having a second wavelength (e.g., about 635 nm). A user, such as a surgeon or surgical staff, can control the surgical laser system 102 (e.g., via a foot switch, voice command, etc.) to alternately emit the laser aiming beam and the treatment beam to treat a patient's anatomy, such as performing photocoagulation. In some cases, the surgical laser system 102 may include a port through which the laser beam can be emitted. The surgical laser system 102 may include a laser system port adapter containing optical elements (not shown) for generating a multi-point pattern of the laser beam from the laser source.

[0033] System 100 can deliver a multiplexed light beam from the port via a multi-core fiber optic cable (MCF) 110 to a surgical probe 108. Probe 108 can generate a multi-point pattern of the laser beam to be delivered to the retina 120 of the patient's eye 125. Probe 108 includes a probe body 112 that houses and protects the MCF 110 and a probe tip 140. The distal portion 145 of the probe tip 140 also includes a lens (not shown, described in more detail below) that translates the multiplexed light beam from the distal end of the MCF 110 onto the retina 120.

[0034] Various systems and methods can be used to create multi-point patterns of laser beams and to multiplex these patterns with an illumination beam. In some cases, a port adapter may include optical elements operable to generate multi-point patterns and / or multiplex beams. In some implementations, the surgical laser system 102 may also include a concave chimney port (not shown), and the port adapter may include a ferrule serving as a convex connector to the concave chimney port. The ferrule may include an opening allowing laser light from the surgical laser system 102 to enter, and one or more optical elements for collimating the laser light received from the laser source. In some examples, the optical element in the ferrule may be a graded-index (GRIN) lens, the length and pitch of which are selected such that the optical element collimates the laser light received at the opening of the ferrule at a selected distance adjacent to a diffractive optical element (DOE). In other examples, the optical element may be one of several other types of lenses (e.g., spherical, aspherical, biconvex glass lenses, etc.). The DOE can focus a multi-point pattern of laser beams onto the interface plane at the proximal end of the MCF, so that each laser beam in the multi-point laser pattern of the laser beam propagates along the entire length of a selected core among the multiple cores contained within the MCF to the distal end of the surgical probe.

[0035] In operation, the laser source of the surgical laser system 102 generates a laser beam. Collimating optics in the surgical laser system 102 are guided to laser collimation by diffractive optics configured to generate a multi-point laser pattern for the laser beam. The multi-point laser pattern is then guided to a condenser lens and focusing optics of the surgical laser system 102 to focus the multi-point pattern onto the proximal interface plane of the MCF, such that each laser beam in the multi-point laser pattern propagates along the entire length of a selected core among a plurality of cores contained within the MCF 110. The multi-point laser pattern is transmitted by the MCF 110 to a probe 108 disposed at the distal end of the MCF 110. The multi-point laser pattern exits the MCF 110 and is transmitted through a lens at the distal portion 145 of the probe 108. The multi-point laser pattern exiting the probe 108 can be projected onto the retina 120 of the eye 125.

[0036] Figure 2 Showed in more detail Figure 1An embodiment of the probe tip 140. As described above, probe 108 includes a probe body 112, the shape and size of which are determined for user gripping. Probe tip 140 extends from probe body 112, and includes a sheath 251 and a cannula 250. As shown, cannula 250 is partially received by sheath 251 and extends beyond its distal end. In the example shown, probe tip 140 includes a straight portion 216 (e.g., the straight portions of sheath 251 and cannula 250) and a curved portion 218 (e.g., the curved portion of cannula 250). In other implementations, probe tip 140 may have other shapes. For example, in some cases, probe tip 140 may be completely straight, include more than one curved portion, be completely curved, or shaped in any desired manner.

[0037] The probe tip 140 can be formed of one or more materials, including, for example, stainless steel, titanium, nitinol, and platinum. In some examples, a first portion of the probe tip 140 (e.g., a straight portion 216) may include a first material, while a second portion of the probe tip 140 (e.g., a curved portion 218) may include a second material. In some cases, the first material may be different from the second material. For example, in some cases, the first material may include stainless steel, such as tubular stainless steel, while the second material may include nitinol, such as tubular nitinol. The distal portion 145 of the probe tip 140 can be inserted into the eye to perform a surgical procedure.

[0038] Figure 3 and Figure 4 The distal end of an exemplary MCF 300 (e.g., similar to MCF 110) is shown from different angles. The MCF 300 includes a plurality of cores 302 disposed within a cladding 304, which may be formed of molten silicon dioxide. The laser source discussed above, such as the laser provided by the surgical laser system 102, can be split into multiple beams. Each beam is directed into one of the cores 302 of the MCF 300. Thus, each core 302 conducts one of the beams along the length of the MCF 300. In some implementations, these cores 302 may be made, for example, of germanium-doped silicon dioxide, and the cladding 304 may be made of molten silicon dioxide, such that the laser traveling along the cores 302 is contained within the cores 302 and prevented from escaping from the cores 302 into the cladding 304. For example, the refractive index of one or more cores 302 may be greater than the refractive index of the cladding 304.

[0039] Although four cores 302 are shown in the illustrated example, the scope of this disclosure is not limited thereto. Rather, in other implementations, the MCF 300 may include fewer cores 302, and in other implementations, it may include more than four cores 302. In some implementations, the MCF 300 may include two, four, or more inner cores 302, and in some examples, these cores 302 may form a 2x2 array that matches a 2x2 multipoint pattern generated by diffractive optics that may be arranged in a surgical laser system, such as surgical laser system 102. A coating 306 is formed on the cladding 304. In some cases, the coating 306 may be a polyimide coating. In other cases, the coating 306 may be formed from other materials, such as acrylate. In some implementations, the refractive index of the coating 306 may be greater than, less than, or equal to the refractive index of the cladding 304.

[0040] In some embodiments, the diameter of each core 302 may be about 75 + / - 2 μm, the outer diameter of the cladding 304 may be about 295 + / - 5 micrometers (μm), and the outer diameter of the coating 506 may be about 325 + / - 5 μm. In some embodiments, the centers of two adjacent cores 302 may be about 126 + / - 5 μm apart, while the distance between the centers of two cores 302 that are diagonally opposite each other may be about 178 + / - 5 μm.

[0041] exist Figure 3 and Figure 4 In this context, MCF 300 is a non-illuminating MCF. That is, while each core 302 is adapted for conducting light, such as laser light, the cladding 304 itself is not used for conducting light for general illumination at the treatment site.

[0042] Figure 5An example of an illuminating MCF, shown as MCF 500, is illustrated. MCF 500 includes a plurality of cores 502 disposed within an inner cladding 504, which may be formed of molten silica. These cores 502 function similarly to the core 302 described above. While four cores 502 are shown in the illustrated example, the scope of this disclosure is not limited thereto. Rather, in other implementations, MCF 500 may include fewer cores 502, and in other implementations, more than four cores 502 may be included. In some implementations, MCF 500 may include two, four, or more inner cores 502, and in some examples, these cores 502 may form a 2x2 array that matches a 2x2 multipoint pattern generated by diffractive optics that may be disposed in a surgical laser system, such as surgical laser system 102. An outer cladding 506 is formed on the inner cladding 504. MCF 500 also includes a coating 508 formed on the outer cladding 506. Coating 508 may refer to the outer cladding. In some cases, the outer cladding 504 and the coating 508 may be formed of polymer materials.

[0043] An illumination MCF is an MCF that transmits light for general illumination (as opposed to targeted lasers for treatment) through its cladding to provide general illumination at the treatment site. Therefore, the inner cladding 504 can be used to transmit light along it to provide general illumination at the treatment site (as opposed to lasers for treatment). In the illumination MCF 500, the refractive index of the outer cladding 506 can be less than that of the inner cladding 504. The outer cladding 506 (which may be a hard silica cladding) can be formed from a polymeric material that may be unstable at high temperatures. Therefore, a portion of the outer cladding 506 can be peeled off or otherwise removed from the MCF 500, as described below, close to the interface with the lens (e.g., about 0.5 to 5 mm), to improve the power manipulation capability of the probe containing the MCF 500. In some embodiments, the coating 508 is removed by a length of about 50 millimeters (mm) measured from the distal end of the MCF 500. This length may correspond to the length of a cannula (e.g., cannula 250). Coating 508 can be removed to allow the MCF500 to be fitted into the cannula, because when coating 508 is on it, the outer diameter of the MCF 500 can be larger than the inner diameter of the cannula.

[0044] In some embodiments, the diameter of each core 502 may be approximately 75 + / - 2 μm, the outer diameter of the inner cladding 504 may be 295 + / - 5 μm, the outer diameter of the outer cladding 506 may be 325 + / - 5 μm, and the outer diameter of the coating 508 may be 425 + / - 30 μm. In some embodiments, the centers of two adjacent cores 502 may be approximately 126 + / - 5 μm apart, while the distance between the centers of two cores 502 that are diagonally opposite each other may be approximately 178 + / - 5 μm.

[0045] Figure 6 yes Figure 2 A detailed cross-sectional view of the distal portion 145 of the probe tip 140 is shown. Note that the distal portion 145 of the probe tip 140 can also be the distal portion of the cannula 250. As described above, the probe tip 140 (including the cannula 250) can be formed of one or more materials, such as stainless steel, titanium, nitinol, or platinum. An MCF 600 (which can be an illuminated MCF (e.g., the MCF 500 described above) or a non-illuminated MCF (e.g., the MCF 300 described above) extends through the cannula 250 of the probe tip 140 and includes a plurality of cores 602, which may be respectively similar to... Figure 3 and Figure 5 Cores 302 and 502 are functional. In the example shown, the MCF 600 includes four cores 602, but as explained above, the MCF 600 may include fewer or additional cores, for example, to provide a desired number of laser beams. For illustrative purposes, the MCF 600 is described as a non-illuminating MCF. However, the scope of this disclosure also includes illuminated MCFs.

[0046] The distal portion 604 of the MCF 600 is located at the distal portion 145 of the probe tip 140 and is described in more detail below. The distal portion 604 terminates at an interface 606 with a lens 608. The interface 606 can be configured to translate the geometry of a multiplexed multi-point laser pattern from the distal end of the MCF 600, through the lens 608, onto a target surface, such as tissue at a treatment site.

[0047] A portion of the cladding 610 of the MCF 600 is removed (e.g., by peeling) at its distal end 616, thereby exposing the cladding 612. Thus, the cladding 612 of the MCF 600 is exposed at interface 606. In some cases, a length L measured from the distal end 616 of the MCF 600 can be removed or omitted from the cladding 610 to mitigate or eliminate thermal problems (e.g., temperature rise at the interface between the MCF 600 and the lens 608), thereby improving the performance of the laser probe. For example, removing the cladding 610 at interface 606 between the MCF 600 and the lens 608 improves the power manipulation characteristics of the probe 108. That is, by removing the cladding 610, the power level of the laser passing through the probe 108 can be greater than the power level of the laser that would have passed through the probe 108 without removing the cladding 610 from the MCF 600 at interface 606. Therefore, with the outer cladding 610 removed as described, a higher thermal load on the probe 108, especially at the interface 606, is possible.

[0048] In some cases, the length L can be in the range of 0.5 mm to 5.0 mm. In other cases, the length L can be in the range of 1.0 mm to 3.0 mm and can be any length therein. Specifically, in some cases, the length L can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, or 3.0 mm. Alternatively, the length L can be any length between these values. At interface 606, the distal end face 618 of the MCF 600 can abut against the proximal end face 614 of the lens 608. In other cases, the distal end face 618 of the MCF 600 can be offset from the proximal end face 614 of the lens 608.

[0049] In some implementations, the distal surface 618 formed at the distal end 616 of the MCF 600 can abut against the proximal surface 614 of the lens 608 with positive pressure. In other implementations, the distal surface 618 of the MCF 600 can be separated from the proximal surface 614 of the lens 608 by an air gap. In still other implementations, one or more optical transmission elements or materials can be located at the interface 606 between the MCF 600 and the lens 608. In some implementations, the lens 608 can be a GRIN lens, a spherical lens, or an aspherical lens. In still other implementations, the lens 608 can be a set of lenses formed of an optically transparent material.

[0050] Lens 608 may include one or more lenses formed of visible transparent glass or ceramic. For example, the material used to form one or more of these lenses 608 may include fused silica, borosilicate, or sapphire. In some implementations, lens 608 may include a single-element cylindrical GRIN rod lens operable to receive one or more laser beams from the distal end 616 of MCF 600 and to redirect the received laser beams toward the distal tip 620 of probe tip 140. In some cases, the distal tip 620 of probe tip 140 may also correspond to the distal end of lens 608. In other cases, a protective window may be arranged between the distal end of lens 608 and the distal tip 620 of probe tip 140. In yet other implementations, the window may extend from the distal tip 620 of probe tip 140.

[0051] Although MCF 600 is described in the context of a non-lighting type, the scope of this disclosure is not limited thereto. Rather, the concepts described herein also apply to lighting MCFs. Therefore, MCF 600 can be a lighting MCF, similar to... Figure 5 The MCF500.

[0052] Figures 7A to 7D , Figures 7E1 to 7E2 ,as well as Figures 7F1 to 7F2Examples of multi-point / multi-fiber laser probes as described herein are compared with those of MCF laser probes to highlight the many different advantages and benefits of MCF laser probes. Figures 7A to 7B Multiple optical fibers 710 (not shown) can be used in multi-point / multi-fiber laser probes, where each fiber 710 is used to conduct a single laser beam. More specifically, Figure 7A A front view of an optical fiber 710 housed within a multi-lumen tube 760 (e.g., a microspacer) is shown. As illustrated, the multi-lumen tube 760 includes four tunnel-shaped passages or apertures 716, each accommodating an optical fiber 710. An adhesive 715 is used to bond each optical fiber 710 to its corresponding aperture 716. Figure 7B A side view of the optical fiber 710 extending from the cannula 750 is shown. Note that... Figure 7B Not shown Figure 7A Multi-lumen tube.

[0053] Typically, precisely controlling multiple individual optical fibers 710 is challenging during the fabrication of multi-point / multi-fiber laser probes. Multi-point / multi-fiber laser probe designs may require precise alignment of multiple individual optical fibers 710 within the inner diameter (ID) of a ferrule to receive the multiple laser beams with the desired high coupling efficiency. For example, using a polyimide tube to manage multiple individual optical fibers 710 and stripping each fiber 710 individually can be time-consuming. After stripping, inserting the multiple optical fibers 710 into corresponding holes in a multi-cavity tube 760 can be difficult and slow. Furthermore, these optical fibers 710 are individually split, retracted into the polyimide tube and multi-cavity tube 760, flush-mounted by stops, and UV-bonded together during adhesion. This assembly then undergoes secondary thermosetting to improve adhesion stability at high temperatures. This fabrication process associated with multi-point / multi-fiber designs is complex and slow. The adhesive 715 used between each optical fiber and its corresponding hole or housing 716 in the multi-cavity tube 760 may also be susceptible to thermal damage and may cause probe failure.

[0054] and Figure 7A and Figure 7B compared to, Figure 7C and Figure 7D The MCF 720 was showcased, similar to... Figures 4 to 6 The MCF 300, MCF 500, and MCF 600 are shown. More specifically, Figure 7C A front view of the MCF 720 is shown, which includes multiple cores 702 embedded in a cladding 704 coated with a coating 724. Figure 7DA side view of the MCF 720 extending from the cannula 752 is shown. As shown, compared to the multiple fibers 710 of a multi-point / multi-fiber laser probe, the MCF 720 is a single fiber with multiple cores 702, each core transmitting a laser beam.

[0055] Laser probes incorporating MCF, such as MCF 720, do not require adhesive between the cores 702, as the cores 702 are embedded in the cladding 704 and contained within a single fiber. Therefore, MCF-incorporated laser probes can exhibit significantly improved power manipulation capabilities. Furthermore, the assembly of MCF laser probes is simpler, as only a single fiber needs to be aligned and manipulated during manufacturing. Consequently, polyimide tubes and multi-cavity tubes are not required to manage multiple individual fibers during assembly, and stripping a single MCF 720 takes significantly less time than stripping multiple individual fibers 710 of a multi-point / multi-fiber probe.

[0056] Furthermore, the use of MCF in laser probes allows for precise control over the direction of the propagating beam. More specifically, using MCF ensures that the beam propagated by the laser probe is precisely controlled and does not point towards the inner surface of the cannula. Figures 7E1 to 7E2 and Figures 7F1 to 7F2 A comparison is shown between the laser beam pattern associated with multiple fibers of a multi-point / multi-fiber laser probe and the laser beam pattern associated with the core of an MCF.

[0057] Figure 7E1 The optical fiber pattern is depicted at the distal end of an optical fiber assembly comprising multiple optical fibers 710 within a multi-cavity tube 760. Figure 7E2 It shows a laser beam point 772, corresponding to Figure 7E1 The laser beam pattern 770 is a fiber pattern. As shown, some fibers 710 (e.g., the upper right core and the lower right core) are not centered within the path 716 of the multi-cavity tube 760, which causes the beam propagating from these fibers 710 to potentially skew outwards, such as... Figure 7E2 As shown. In some cases, some optical fibers 710 may not be centered within their corresponding passages 716 due to a loose tolerance between the outer diameter of the optical fiber 710 and the inner diameter of the passage 716 of the multi-lumen tube 760, causing the optical fiber 710 to instead point towards the inner surface of the cannula (not shown). Therefore, the beam propagated by the optical fiber 710 also points towards the inner surface of the cannula, rather than towards the patient's eye in a straight line. This causes these beams to escape from the lens of the laser probe, such as lens 608, and be absorbed by the inner surface of the cannula, potentially leading to overheating of the cannula. Furthermore, the lack of centering of the optical fiber 710 within its corresponding passage 716 results in undesirable uniformity between the four corresponding beam points.

[0058] and Figures 7E1 to 7E2 compared to, Figures 7F1 to 7F2The fiber pattern and bundle pattern associated with MCF are shown respectively. Figure 7F1 The cores 702 of the MCF are shown, pointing in a straight direction and not tilted outwards. This is because these cores 702 are tightly embedded together within the cladding. Therefore, the cores 702 are able to propagate the bundle point 782 ( Figure 7F2 As shown in beam pattern 782, these beam points also point in a straight direction and not toward the inner surface of the cannula (not shown) in which the MCF is housed. In this way, the use of the MCF improves the control of the laser beam pattern of the laser probe (e.g., the desired uniformity between the four beam points) and increases power manipulation by preventing overheating of the cannula due to the beam pointing toward the inner surface of the cannula.

[0059] Therefore, the disclosed MCF laser probe design simplifies manufacturing by eliminating complex and costly manufacturing requirements, improves power control by eliminating adhesive failure during the bonding of multiple fibers at their distal ends or by eliminating the introduction of contaminants into the distal fiber assembly of the multi-fiber probe, increases coupling efficiency by employing a precisely aligned MCF and avoiding the difficulties associated with aligning individual fibers with multiple input laser beams in a multi-fiber assembly, and improves control over the laser beam pattern (which further improves power control). These and other advantages will be apparent to those skilled in the art in light of this disclosure.

[0060] Figure 8 An exemplary flowchart 800 is shown, illustrating steps in a method for applying a multi-point laser beam pattern according to a specific embodiment of the present invention. In some embodiments, operation 800 is performed by a system, such as... Figure 1 The surgical laser system 102 performs the procedure, the system being coupled to an MCF laser probe, such as... Figure 1 MCF laser probe 108.

[0061] In box 802, the system generates a laser beam via a laser source. As described above, the laser source may be part of or connected to the surgical laser system 102.

[0062] At box 804, the system collimates the laser beam. A collimated laser beam is a laser beam with parallel rays.

[0063] At block 806, the system guides the collimated laser beam to a diffractive optical element (DOE), which is configured to generate a multi-point laser pattern for the laser beam. As those skilled in the art will recognize, the DOE is used to shape and split the laser beam.

[0064] At frame 808, the system guides the laser beam in a multi-point pattern to the focusing lens.

[0065] At box 810, the system focuses a multi-point pattern of laser beams onto the interface plane near the MCF, such that each laser beam in the multi-point laser pattern of the laser beam is transmitted to and propagates along one of the multiple cores of the MCF, which are surrounded by a cladding, and the cladding is surrounded by a coating, each of the multiple cores having a refractive index greater than that of the cladding, and a portion of the coating is omitted from a length from the far end of the MCF.

[0066] For example, surgical laser system 102 focuses a multi-point pattern of laser beams onto the interface plane of the proximal end of an MCF (e.g., MCF 110, MCF 300, MCF 500, MCF 600, etc.), such that each laser beam in the multi-point laser pattern is transmitted to and propagates along one of a plurality of cores of the MCF (e.g., cores 302, 502, 602, etc.), said plurality of cores being surrounded by cladding (e.g., cladding 304, 504, 506, 612), and the cladding being surrounded by coatings (e.g., 306, 508, etc.), the refractive index of each of said plurality of cores being greater than the refractive index of the cladding, and from a distance of a length from the distal end of the MCF (e.g., ... Figure 6 (The length L is shown) omitting a portion of the coating.

[0067] At box 812, the system transmits a multi-point pattern of the laser beam to the far end of the MCF. For example, the system transmits a multi-point pattern of the laser beam to the far end of the MCF (e.g., far end 616).

[0068] At frame 814, the system guides a multi-point pattern of laser beam through a lens (e.g., lens 608) to the distal tip (e.g., distal tip 620) of a surgical probe (e.g., probe 108).

[0069] Figure 9A distal portion of another exemplary probe 901, operable to generate a multi-point pattern of laser beams, is shown. The exemplary probe 901 shown includes an illumination MCF 900, which may be similar to the MCF 500 described above. Thus, probe 901 is operable to emit both general illumination for illuminating a surgical area and multiple laser beams for treating a treatment site, such as the retina. Probe 901 may be similar to probe 108 in many respects. As shown, probe 901 includes a cannula 902. Cannula 902 includes an inner surface 936 defining an internal passage 942. MCF 900 extends through at least a portion of cannula 902 to a first interface 906 with lens 908. MCF 900 may abut against lens 908, or a gap, such as an air-filled gap, may be provided between the distal end 916 of MCF 900 and the proximal end 914 of lens 908. In some cases, the distal end 916 of the MCF 900 can abut against the proximal end 914 of the lens 908 with positive pressure. In some cases, the lens 908 can be formed of fused silica, borosilicate, or sapphire. In some cases, the lens 908 can be a spherical lens. The lens 908 can be a GRIN lens, such as a single-element cylindrical GRIN rod lens, operable to receive one or more laser beams from the distal end of the MCF 900 and redirect the received laser beams toward the distal tip 920 of the probe 901.

[0070] The probe 901 also includes a protective window 918 that extends from the second interface 922 with the lens 908. For example... Figure 9 As shown, the protective window 918 abuts against the lens 908. In other implementations, a gap, such as an air-filled gap, may exist between the protective window 918 and the lens 908. In the example shown, the protective window 918 extends distally beyond the distal end 924 of the cannula 902, and the distal end 926 of the protective window 918 defines the distal tip 920 of the probe 901. In other implementations, the distal end 926 of the protective window 918 may be aligned with the distal end of the distal end 924 of the cannula 902 such that the distal end 924 of the cannula 902 and the distal end 926 of the protective window 918 are substantially flush. Those skilled in the art will recognize that the relative positions of the end surfaces of the distal end 924 of the cannula 902 and the distal end 926 of the protective window 918 may vary slightly due to manufacturing tolerances.

[0071] The protective window 918 can be formed of an optically stable and high-temperature resistant material. In some cases, the protective window 918 can be formed of sapphire or quartz. In some cases, the protective window 918 can have a flat proximal surface, such as... Figure 9 As shown. In other cases, the protective window 918 may have a convex proximal surface 928. Figure 10An example of this type of lens is shown.

[0072] exist Figure 10 In this embodiment, lens 1008 has convex proximal and distal ends. Although lens 1008 is elongated in the longitudinal direction, in other examples it can instead be a spherical or spherical lens. In some implementations, lenses with flat proximal and / or flat distal ends, such as... Figure 9 The lens 908 shown can be used in conjunction with the protective window 1018, which has a convex proximal end, similar to... Figure 10 As shown. In other implementations, the probe may include a lens with a convex proximal end and / or a convex distal end, such as a spherical lens or Figure 9 The lens shown is used with a protective window having a flat proximal end, for example... Figure 9 The protection window 918 shown is combined.

[0073] See back Figure 9 MCF 900 includes an outer cladding layer 930, which can be similar to... Figure 5 The outer sheath 506 is shown. The outer sheath 930 is peeled off from the inner sheath 932, for example, by peeling off a length L measured from the distal end 916 of the MCF 900 and extending proximally, thereby exposing the underlying inner sheath 932.

[0074] In some cases, the length L can range from 0.5 mm to 5.0 mm. In other cases, the length L can range from 1.0 mm to 3.0 mm and can be any length therein. Specifically, in some cases, the length L can be 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, or 3.0 mm. Additionally, the length L can be any length between these values. As explained above, removing a portion of the outer cladding can improve the thermal manipulation characteristics of the probe, thereby increasing the power level of laser energy transmitted through the probe. A portion of the core 933 extending through the inner cladding 932 is shown.

[0075] However, with a portion of the outer cladding 930 removed, an annular gap 934 exists between the inner cladding 932 and the inner surface 936 of the cannula 902. The annular gap 934 introduces the risk of misalignment between the MCF 900 and the lens 908 (i.e., the MCF 900 may be off-center relative to the lens 908). Figure 11 This is a side view of the exposed end 938 of probe 901, where the exposed end 938 of MCF 900 is aligned with lens 908. The exposed end 938 of MCF 900 is the portion of MCF 900 with the outer sheath 930 removed.

[0076] However, Figure 12This illustrates that the exposed end 938 of the MCF 900 is misaligned with the lens 908 due to the annular gap 934. (As shown...) Figure 12 As shown, the exposed end 938 of the MCF 900 is not concentric with the lens 908. When the exposed end 938 of the MCF 900 is misaligned with the lens 908, the resulting laser spot and illumination beam pattern are no longer concentric with the cannula 902. This misalignment between the MCF 900 and the lens 908 may also cause some light to be propagated for general illumination and pass through the inner cladding 932, impacting the inner wall 936 of the cannula 902. This reduces the illumination efficiency of the probe 901 and results in an undesirable illumination pattern.

[0077] In some embodiments, to maintain alignment between the MCF 900 and the lens 908, a ring formed of a thermally stable material may be arranged in the annular gap 934 to maintain concentricity between the MCF 900 and the internal passage of the cannula and the lens. In some embodiments, the material may include, for example, polyimide, metal, stainless steel, nickel, silver, copper, brass, etc. While polyimide and metal are possible materials for manufacturing the ring, other materials may also be used. Figure 13 An example of a ring used to maintain alignment between the MCF 900 and the lens 908 is shown.

[0078] Figure 13 A ring 940 is shown disposed within an annular gap 934 formed around the inner cladding 932 at the exposed end 938 of the MCF 900. The ring 940 maintains the concentricity of the MCF 900 and the lens 908, for example, by restricting lateral movement of the exposed end 938 of the MCF 900. In some cases, the inner diameter of the ring 940 corresponds to the outer diameter of the exposed end 938 of the MCF 900. In other cases, the outer diameter of the ring 940 corresponds to the inner diameter of the internal passage 942. The ring 940 may span the entire length L of the exposed end 938 or be less than the entire length L.

[0079] Figure 14 Another exemplary implementation for maintaining alignment between the MCF 900 and the lens 900 is shown. Figure 14In the example shown, cannula 1402 includes an internal passage 942 having a first inner diameter 1444 that more closely matches the outer diameter of MCF 900. Cannula 1402 also includes a countersunk hole 946 having a second inner diameter 1448 larger than the first inner diameter 1444. The countersunk hole 946 is configured to accommodate a lens 908 and a protective window 918 (if included) within cannula 1402 because the cross-sectional size of these components is larger than that of the MCF 900. Therefore, along the exposed end 938, the passage 942, with its reduced cross-sectional size compared to the countersunk hole 946, is able to maintain greater alignment between the exposed end 938 of the MCF 900 and the lens 908 compared to a situation where the inner diameter 1444 of the passage 942 is the same as the inner diameter 1448 of the countersunk hole 946. This improves the alignment between the MCF 900 and the lens 908. In some cases, the countersunk hole 946 extends proximally from the distal end of the cannula 1402.

[0080] Figure 15 The following example is shown: The reduced inner diameter 1550 of the cannula 1502 provides alignment of the exposed end 938 of the MCF 900. The necked portion 1552 of the cannula 1502 (possibly a result of coiling) provides the reduced diameter 1550. This reduced inner diameter 1550 can correspond to the outer diameter of the exposed end 938 of the MCF 900. The reduced inner diameter 1550 maintains the alignment of the exposed end 938 with the lens 908, thereby achieving improved general illumination performance and alignment of the laser dot pattern with the longitudinal axis of the cannula 1502.

[0081] Figure 16 Shown in Figure 15 The background shown illustrates the potential risk of damage to the MCF 900 during the assembly of the multi-point laser probe. If the necked portion 1652 of the cannula 1602 (e.g., formed by a curling applied to the cannula 1602) is formed before the MCF 900 is introduced into the necked portion 1652, there is a risk of damage to the distal end 1654 (especially the edge 1656 of the distal end 1654) when attempting to insert it through the necked portion 1652. During assembly, misalignment of the distal end 1654 with the necked portion 1652 can generate forces that may gouge and damage the distal end 1654 of the MCF 900. Even small loads applied to the distal end 1654, especially its edge 1656, can cause damage, such as gouging of the distal end 1654 and the edge 1656, resulting in performance degradation regardless of poor general lighting, inaccurate or distorted laser dot patterns, or both. Such damage may render the resulting laser probe unusable. Therefore, a necking portion can be formed in the cannula after the MCF is introduced, such as... Figure 17 and Figure 18 As shown.

[0082] Figure 17 and Figure 18 The distal end 1654 of the MCF 800 is shown abutting the lens 908 at the first interface 906. However, as explained above, a gap may be provided between the distal end 1654 of the MCF 800 and the lens 908. In some implementations, one or both of the lens 908 and the window 918 may be mounted in the insertion tube 1702 before the MCF 900 is assembled. In some implementations, the MCF 900 may be mounted before one or both of the lens 908 and the window 918.

[0083] When the MCF 900 is positioned at the desired location within the cannula 1702, a necking portion 1752 can be formed within the cannula 1702, for example, by coiling. The necking portion 1752 maintains the concentricity of the exposed end 938 of the MCF 900 with the lens 908. This eliminates the risk of damage to the distal end 1654 of the MCF 900 by the necking portion 1752.

[0084] In some cases, the necking portion 1752 is a reduced annular body that completely surrounds the exposed end 938 of the MCF 900. Thus, the necking portion 1752 defines a reduced diameter 1858 of the internal passage 942 that corresponds to the outer diameter of the exposed end 938. In some cases, the reduced diameter 1858 of the necking portion 1752 is equal to or slightly larger than the outer diameter of the exposed end 938. As an example, a 5 μm annular gap may be formed between the inner surface of the cannula 1702 at the necking portion 1752 and the outer surface of the exposed end 938. In some embodiments, the exposed end 938 may contact the inner surface of the necking portion 1752 at one or more locations.

[0085] In some embodiments, the necking portion 1752 may have diametrically opposed protrusions formed at one or more locations around the circumference of the cannula 1702, thereby aligning the exposed end 938 of the MCF 900 with the lens 908. For example, in some cases, the necking portion 1752 may include two sets of diametrically opposed protrusions offset from each other by 90°. In some other implementations, three or more non-diametrically opposed protrusions may be formed in the cannula to center the exposed end 938 of the MCF 900. In some cases, protrusions may be formed along a common circumference of the cannula 1702. In other implementations, one or more protrusions may be longitudinally offset relative to one or more other protrusions.

[0086] Additionally, although the MCF 900 is described as an illumination MCF, in some implementations the MCF 900 can be a non-illumination MCF and is still within the scope of this disclosure.

[0087] Figure 19 An exemplary flowchart 1900 is shown according to a specific embodiment of the present invention, illustrating steps in a method for generating a multi-point laser probe.

[0088] At frame 1902, a probe tip is provided, which includes a cannula configured for insertion into the eye. For example, a technician or machine could provide a probe tip 901 with a cannula 1702, such as... Figure 18 As shown.

[0089] At frame 1904, insert the lens into the cannula. For example, insert lens 908 into cannula 1702.

[0090] At frame 1906, the MCF is inserted into the cannula near the lens. For example, the MCF 900 is inserted into cannula 1702 near the lens 908. The MCF 900 includes a plurality of cores 933. As shown, the MCF 900 includes a cladding 932, shown at the exposed end 938 of the MCF 900.

[0091] At frame 1908, a necking portion is formed in the cannula, the necking portion having a reduced cross-sectional size to maintain the exposed portion of the MCF centered within the cannula. For example, a necking portion 1752 is formed in cannula 1702.

[0092] While some of the accompanying figures described herein illustrate a probe with a protective window, it should be understood that the protective window may be omitted. Further within the scope of this disclosure, the ends of the lens and / or protective window may be shapes other than flat. For example, one or more of the distal and proximal ends of the lens and / or protective window may have a convex shape, as described herein.

[0093] The subject matter disclosed above should be considered illustrative rather than restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments falling within the true spirit and scope of this disclosure. Therefore, for the maximum permissible extent permitted by law, the scope of this disclosure shall be determined by the broadest possible interpretation of the following claims and their equivalents and shall not be limited to or confined to the specific embodiments described above.

Claims

1. A multi-point laser probe system, comprising: Laser source; Diffractive optical elements are optically connected to the laser source; The probe body, the shape and size of which are determined for the user to grip; A probe tip, the probe tip including a cannula configured for insertion into the eye; A graded-index GRIN lens arranged in the insertion tube; A protective window at the distal portion of the cannula; A multi-core optical fiber (MCF) extending at least partially through the cannula, the MCF comprising: Multiple cores with uniform core diameter and spacing; A cladding layer surrounding the plurality of cores, wherein the refractive index of one or more of the plurality of cores is greater than the refractive index of the cladding layer; The proximal end optically connected to the diffractive optical element; and Arranged at the distal end of the interface with the GRIN lens, and The diffractive optical element is configured to separate the laser from the laser source to generate a multi-point pattern of laser beams entering the interface plane at the near end of the multi-core optical fiber to simultaneously transmit the multi-point laser beams along the plurality of cores of the multi-core optical fiber, wherein the multi-point pattern is configured to be aligned with the uniform diameter and spacing of the plurality of cores. The GRIN lens is positioned between the distal end of the MCF and the protective window.

2. The multi-point laser probe system as described in claim 1, wherein, The distal end of the MCF abuts against the GRIN lens at the interface with positive pressure.

3. The multi-point laser probe system as described in claim 1, wherein, The cladding is further configured to transmit general illumination light, such that the probe is configured to emit general illumination light and the multi-point laser beam.

4. The multi-point laser probe system as described in claim 1, further comprising: A second cladding layer surrounding the cladding layer, the second cladding layer comprising a polymer, and A coating surrounding the second cladding layer, the coating comprising a polymer.

5. A multi-point laser probe system, comprising: Laser source; Diffractive optical elements are optically connected to the laser source; A multi-core optical fiber (MCF) includes a plurality of cores surrounded by a cladding, wherein the plurality of cores have a uniform core diameter and spacing, and wherein the refractive index of one or more of the plurality of cores is greater than the refractive index of the cladding, wherein the near end of the multi-core optical fiber is optically connected to the diffractive optical element, and wherein the far end of the multi-core optical fiber is disposed at the interface with a GRIN lens. A probe, the probe including a probe tip coupled to the distal end of the MCF; as well as A protective window at the distal end of the intubation tube; The GRIN lens is located at the distal end of the probe tip, and The distal end of the MCF terminates at the interface with the GRIN lens; The diffractive optical element is configured to separate the laser from the laser source to generate a multi-point pattern of laser beams entering the interface plane at the near end of the multi-core optical fiber to simultaneously transmit the multi-point laser beams along the plurality of cores of the multi-core optical fiber, wherein the multi-point pattern is configured to be aligned with the uniform diameter and spacing of the plurality of cores. The GRIN lens is positioned between the distal end of the MCF and the protective window.

6. The multi-point laser probe system of claim 5, further comprising a coating surrounding the cladding.

7. The multi-point laser probe system as described in claim 5, The plurality of cores comprises germanium-doped silicon dioxide; and The cladding layer comprises molten silicon dioxide.

8. The multi-point laser probe system as described in claim 5, wherein, The probe tip includes a cannula configured for insertion into the eye, wherein the distal end of the MCF and the GRIN lens are disposed within the cannula.

9. The multi-point laser probe system as described in claim 5, wherein, The cladding is further configured to transmit general illumination light, such that the probe is configured to emit general illumination light and the multi-point laser beam.

10. The multi-point laser probe system of claim 5, further comprising: A second cladding layer surrounding the cladding layer, the second cladding layer comprising a polymer, and A coating surrounding the second cladding layer, the coating comprising a polymer.

11. A method for applying a multi-point laser beam pattern, the method comprising: A laser beam is generated using a laser source; The laser beam is collimated; The collimated laser beam is guided to a diffractive optical element (DOE), which is configured to generate a multi-point laser pattern for the laser beam. Guide the multi-point pattern of the laser beam to the focusing lens; A multi-point pattern of laser beams is focused onto the interface plane at the near end of a multi-core fiber MCF, such that each laser beam in the multi-point laser pattern of the laser beam is transmitted to one of the multiple cores of the MCF and propagates along it, the multiple cores having a uniform core diameter and spacing, and wherein the multiple cores are surrounded by a cladding, wherein the refractive index of each of the multiple cores is greater than the refractive index of the cladding. The multi-point pattern of the laser beam is transmitted to the far end of the MCF, wherein the laser beam of the multi-point pattern is transmitted simultaneously along multiple cores of the multi-core fiber, wherein the multi-point pattern is configured to be aligned with the uniform diameter and spacing of the multiple cores.

12. The method of claim 11, wherein a second cladding layer surrounds the cladding layer, the second cladding layer comprising a polymer, and wherein a coating surrounds the second cladding layer, the coating comprising a polymer.

13. The method of claim 11, further comprising: General illumination light is directed onto the cladding so that it is transmitted along the cladding.

14. The method of claim 11, wherein the MCF further comprises: A second cladding layer surrounding the cladding layer, the second cladding layer comprising a polymer, and A coating surrounding the second cladding layer, the coating comprising a polymer.

15. The method of claim 11, wherein the plurality of cores comprises germanium-doped silicon dioxide, and the cladding comprises molten silicon dioxide.

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