Optical combiner for distributing laser / power to multi-core output fiber and laser system incorporating same

Abstract

An optical combiner includes: an optical fiber bundle having a plurality of input optical fibers; an output fiber having an inner core surrounded by an outer core; a splice that fuses the optical fiber bundle to the output optical fiber; at least a first input fiber from the plurality of input fibers, the at least first input fiber being aligned and registered with the inner core; and at least a second input fiber from the plurality of input fibers, the at least second input fiber being aligned and registered with the outer core. A laser system combines a light combiner with a plurality of lasers that generate laser light.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application relies on and claims priority from U.S. Provisional Patent Application No. 63 / 410,370 filed on September 27, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present invention relates to a structure of an optical combiner for distributing laser / power to a multi-core output optical fiber. More specifically, in at least one embodiment, the present invention is contemplated to include a structure of an optical combiner for distributing laser / power between an inner core and an outer core of a multi-core output optical fiber. The present invention also includes a laser system incorporating the optical combiner. Background Art

[0004] As will be apparent to those skilled in the art, it is commonplace to connect one or more lasers to an output optical fiber so that laser light generated by the lasers can be directed to a target area via the output optical fiber.

[0005] To this end, the prior art provides a variety of solutions.

[0006] Some of these solutions involve lenses and optical focusing devices that couple and concentrate / direct the laser light into the output fiber.

[0007] Other solutions involve only optical fiber components. Summary of the invention

[0008] Among other objects, the present invention aims to provide a structure for an optical combiner that connects two or more lasers to a multi-core output optical fiber via an optical fiber bundle in a simple and reliable manner.

[0009] Therefore, one aspect of the present invention is to provide an optical combiner, which includes a fiber bundle having a plurality of input optical fibers and an output optical fiber having an inner core surrounded by an outer core. The fiber bundle is fused to the output optical fiber. At least a first input optical fiber from the plurality of input optical fibers is aligned with the inner core. At least a second input optical fiber from the plurality of input optical fibers is aligned with the outer core.

[0010] In one contemplated embodiment of the optical combiner, at least one of the plurality of input optical fibers comprises a plurality of claddings.

[0011] In another contemplated embodiment of the optical combiner, the output optical fiber comprises multiple claddings.

[0012] In another embodiment, the optical combiner may be configured such that the plurality of input fibers include a first input fiber, a second input fiber, a third input fiber, a fourth input fiber, a fifth input fiber, a sixth input fiber, and a seventh input fiber.

[0013] In this configuration, the first input fiber is envisioned to be surrounded by the second, third, fourth, fifth, sixth and seventh input fibers.

[0014] Here, the third input fiber, the fourth input fiber, the fifth input fiber, the sixth input fiber, and the seventh input fiber are also aligned and registered with the outer core.

[0015] In another contemplated embodiment, the plurality of input optical fibers includes a first input optical fiber, a second input optical fiber, and a third input optical fiber.

[0016] Here, the first input fiber is disposed adjacent to the second input fiber and the third input fiber in a linear configuration.

[0017] In this configuration, the second and third input fibers are envisioned to be in alignment with the outer core.

[0018] In another contemplated configuration of the optical combiner of the present invention, the first input optical fiber is arranged adjacent to the second input optical fiber and the third input optical fiber in a triangular configuration.

[0019] In this configuration, the third input fiber is also aligned with the outer core.

[0020] It is contemplated that the optical combiner of the present invention may be incorporated with a glass support structure wherein a plurality of input optical fibers are disposed within the glass support structure.

[0021] It is also contemplated that the optical combiner may be configured such that the output fiber includes a first output fiber segment that is fused to a second output fiber segment at a second splice.

[0022] If so, the second splice may be a multi-core step-up splice.

[0023] The present invention is also contemplated to include a laser system that combines multiple lasers that generate laser light and an optical combiner connected to the multiple lasers. The optical combiner includes: a fiber bundle having multiple input fibers that receive laser light from the multiple lasers; an output fiber having an inner core surrounded by an outer core that receives laser light from the fiber bundle; a connector that fuses the fiber bundle to the output fiber; at least a first input fiber from the multiple input fibers, the at least first input fiber being aligned with the inner core; and at least a second input fiber from the multiple input fibers, the at least second input fiber being aligned with the outer core.

[0024] In one contemplated embodiment of the laser system, at least one of the plurality of input fibers comprises a plurality of claddings.

[0025] In another contemplated embodiment of the laser system, the output optical fiber comprises multiple claddings.

[0026] In contemplated embodiments, the laser system may be configured such that the plurality of input fibers include a first input fiber, a second input fiber, a third input fiber, a fourth input fiber, a fifth input fiber, a sixth input fiber, and a seventh input fiber, a first laser from the plurality of lasers provides light to the first input fiber, and at least a second laser from the plurality of lasers provides light to at least a second input fiber.

[0027] Here, the first input optical fiber may be surrounded by the second input optical fiber, the third input optical fiber, the fourth input optical fiber, the fifth input optical fiber, the sixth input optical fiber, and the seventh input optical fiber.

[0028] It is contemplated that the laser system may be configured such that the third, fourth, fifth, sixth, and seventh input fibers are also aligned with the outer core.

[0029] In another contemplated configuration of the laser system, the plurality of input fibers includes a first input fiber, a second input fiber, and a third input fiber, a first laser from the plurality of lasers provides light to the first input fiber, and at least a second laser from the plurality of lasers provides light to at least the second input fiber.

[0030] Here, the first input fiber is arranged adjacent to the second input fiber and the third input fiber in a linear configuration. If so, the third input fiber is envisioned to be aligned with the outer core.

[0031] In another configuration, the laser system is configured so that the first input fiber is disposed adjacent to the second input fiber and the third input fiber in a triangular configuration. If so, the third input fiber is also contemplated to be aligned with the outer core.

[0032] The laser system may also be configured to include a glass support structure, wherein a plurality of input optical fibers are disposed in the glass support structure.

[0033] Furthermore, the laser system may include an output fiber, wherein the first output fiber segment is fused to the second output fiber segment at a second joint. The second joint may be a multi-core step joint.

[0034] Other advantages and features of the present invention will become more apparent from the discussion given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The present invention will now be described in conjunction with the accompanying drawings, in which:

[0036] Figure 1 is a diagrammatic side view of a first embodiment of a laser system incorporating a contemplated embodiment of the optical combiner of the present invention;

[0037] Figure 2 A diagrammatic cross-sectional view of a first embodiment of an input fiber bundle and a diagrammatic cross-sectional view of a contemplated embodiment of an output fiber, wherein the input fiber bundle and the output fiber are contemplated to be fused to each other in the optical combiner of the present invention;

[0038] Figure 3 for Figure 2 a combined pictorial cross-sectional view of a first embodiment of an input fiber bundle and an output fiber, illustrating one manner in which the first embodiment of the input fiber bundle is contemplated to be aligned with the output fiber when it is fused to one another;

[0039] Figure 4 Shows Figure 2 A diagrammatic cross-sectional view of a second embodiment of an input fiber bundle is shown and Figure 2 A diagrammatic cross-sectional view of an output optical fiber is shown, wherein the input optical fiber bundle and the output optical fiber are envisioned to be fused to each other in the optical combiner of the present invention;

[0040] Figure 5 yes Figure 2 a combined pictorial cross-sectional view of a second embodiment of an input fiber bundle and an output fiber, illustrating one manner in which the second embodiment of the input fiber bundle is contemplated to be aligned with the output fiber when it is fused to one another;

[0041] Figure 6 Shows Figure 2 A diagrammatic cross-sectional view of a third embodiment of an input fiber bundle is shown and Figure 2 A diagrammatic cross-sectional view of an output optical fiber is shown, wherein the input optical fiber bundle and the output optical fiber are envisioned to be fused to each other in the optical combiner of the present invention;

[0042] Figure 7 yes Figure 2 a combined pictorial cross-sectional view of a third embodiment of an input fiber bundle and an output fiber, illustrating one manner in which the third embodiment of the input fiber bundle is contemplated to be aligned with the output fiber when it is fused to one another;

[0043] Figure 8 Shows Figure 2 A diagrammatic cross-sectional view of a fourth embodiment of an input fiber bundle is shown and Figure 2 A diagrammatic cross-sectional view of an output optical fiber is shown, wherein the input optical fiber bundle and the output optical fiber are envisioned to be fused to each other in the optical combiner of the present invention;

[0044] Fig. 9 for Figure 2 a combined pictorial cross-sectional view of a fourth embodiment of an input fiber bundle and an output fiber, illustrating one manner in which the fourth embodiment of the input fiber bundle is contemplated to be aligned with the output fiber when it is fused to one another;

[0045] Fig.10 is a diagrammatic side view of a second contemplated embodiment of the laser system of the present invention, showing a contemplated variation of the configuration of the output optical fiber;

[0046] Fig.11 is a diagrammatic cross-sectional view of a fifth embodiment of an input fiber bundle, which is conceived as Figure 3 A variation of the first embodiment of the input fiber bundle shown;

[0047] Fig.12 is a pictorial cross-sectional side view of a multi-core step connector of the type that may be used in conjunction with the present invention; and

[0048] Fig.13 is a graphical representation of a cross-section of an optical fiber having multiple claddings. DETAILED DESCRIPTION

[0049] The present invention will now be described in conjunction with one or more embodiments. Where possible, the same reference numerals are used to refer to similar structures and / or features. Unless otherwise specified, the use of the same reference numerals should not be understood to mean that each structure using the same reference numeral is identical to each other structure using the same reference numeral. On the contrary, it is obvious to those skilled in the art that variations and equivalents of these structures may be adopted. Even if not explicitly discussed herein, these variations and equivalents are considered to be included by the present invention.

[0050] The present invention will also be described in conjunction with one or more materials. Any material described herein is intended to be an example of a possible material that can be adopted, and is not intended to limit the scope of the present invention. In addition, unless otherwise stated, any discussion of the specific characteristics and parameters of any material should not be construed as a limitation on the material.

[0051] The various illustrations of the present invention are not drawn to scale unless otherwise specified. As a result, any applicable dimensions are intended to be included in these drawings.

[0052] Figure 1 is a diagrammatic side view of a laser system 10 in accordance with the teachings of the present invention. The laser system 10 incorporates one contemplated embodiment of an optical combiner 12 in accordance with the present invention.

[0053] In the illustrated embodiment, the laser system 10 includes seven lasers 14 , 16 , 18 , 20 , 22 , 24 , 26 connected to seven input optical fibers 28 , 30 , 32 , 34 , 36 , 38 , 40 .

[0054] Although seven lasers 14, 16, 18, 20, 22, 24, 26 are shown, it is contemplated that any number of lasers greater than or equal to two may be employed by the laser system 10. Thus, in several contemplated embodiments, the laser system 10 may employ two, three, four, five, six, seven, or more lasers without departing from the scope of the present invention.

[0055] Likewise, although seven input fibers 28, 30, 32, 34, 36, 38, 40 are shown, it is contemplated that any number of input fibers greater than or equal to two may be employed with the laser system 10. Thus, the laser system 10 may employ two, three, four, five, six, seven, or more input fibers without departing from the scope of the present invention.

[0056] It is worth noting that, in theory, there is no upper limit to the number of lasers and input fibers that may be employed / used in the present invention. However, practical considerations suggest that the maximum number may be about 19 lasers and 19 input fibers. Therefore, in other embodiments, it is contemplated that the laser system 10 may include eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, or nineteen lasers and / or input fibers.

[0057] In the illustrated embodiment, one laser is associated with one input fiber. It is noteworthy that this association is merely illustrative of one contemplated arrangement of lasers and input fibers. For example, in alternative arrangements and configurations, multiple lasers may be connected to a single input fiber without departing from the scope of the present invention. Likewise, multiple input fibers may be connected to a single laser. Furthermore, it is contemplated that one or more input fibers may not be connected to a laser at all.

[0058] The laser system 10 of the present invention is contemplated to require at least two lasers and two input fibers. However, the actual number may be selected as needed or desired for a particular installation and / or application, as should be apparent to one skilled in the art.

[0059] exist Figure 1 In the illustrated embodiment, the lasers 14, 16, 18, 20, 22, 24, 26 may be of any type. The lasers may generate light of different intensities from one another. The lasers may also generate light of different wavelengths from one another.

[0060] In one non-limiting example, each of the lasers 14, 16, 18, 20, 22, 24, 26 may generate light of the same power.

[0061] In one non-limiting example, each of the lasers 14, 16, 18, 20, 22, 24, 26 may generate light of the same wavelength. In other non-limiting examples, the lasers 14, 16, 18, 30, 22, 24 may generate light of different wavelengths from one another.

[0062] Although not intended to limit the present invention, by way of example only, it is suggested that each of the lasers 14, 16, 18, 20, 22, 24, 26 may be a 1 kW laser, meaning that each laser generates 1 kW of output light. In other non-limiting examples, one or more of the lasers 14, 16, 18, 20, 22, 24, 26 may be a ≤ 1 kW, 1 kW, 2 kW, 3 kW, 4 kW, 5 kW, 6 kW, and / or ≥ 6 kW laser, or other power levels. The lasers 14, 16, 18, 20, 22, 24, 26 need not generate the same power to remain within the scope of the present invention.

[0063] As should be apparent to one skilled in the art, the lasers 14, 16, 18, 20, 22, 24, 26 may have any wavelength and any output intensity / power as desired / required for a particular application. In other words, as is apparent from the foregoing non-limiting examples, the scope of the present invention is not limited to any particular laser power and / or wavelength. Furthermore, one or more of the lasers 14, 16, 18, 20, 22, 24, 26 may be single mode or multimode lasers without departing from the scope of the present invention.

[0064] It is also contemplated that one or more of the lasers 14, 16, 18, 20, 22, 24, 26 may be controllable, such that, for example, the output power may be adjusted during operation. One or more of the lasers 14, 16, 18, 20, 22, 24, 26 may also be adjustable in other ways without departing from the scope of the present invention.

[0065] like Figure 1 As shown, input optical fibers 28, 30, 32, 34, 36, 38, 40 extend from lasers 14, 16, 18, 20, 22, 24, 26 to optical fiber bundle 42. Input optical fibers 28, 30, 32, 34, 36, 38, 40 are contemplated to be made primarily of fused silica with suitable dopants known to those skilled in the art. These dopants are typically used to increase or decrease the refractive index.

[0066] The details of the optical fiber bundle 42 will be combined Figures 2 to 9 The illustrated embodiment is described.

[0067] It is worth noting that although the fiber bundle 42 is shown as a separate structure, the fiber bundle should not be considered as a structure and / or component that is independent of the input optical fibers 28, 30, 32, 34, 36, 38, 40. Instead, the name of the fiber bundle 42 is intended to describe a structure in which the input optical fibers 28, 30, 32, 34, 36, 38, 40 are combined together so that the laser light from the lasers 14, 16, 18, 20, 22, 24, 26 can be introduced and / or input into the output optical fiber 44. The fiber bundle 42 can be a structure in which the input optical fibers 28, 30, 32, 34, 36, 38, 40 are fused together, for example, fused into a single component.

[0068] As with input optical fibers 28, 30, 32, 34, 36, 38, 40, output optical fiber 44 is contemplated to be made primarily of fused silica with appropriate dopants known to those skilled in the art.

[0069] The fiber bundle 42 is connected to the output optical fiber 44 via a first connector 46. Details of the connector are not provided here because connectors are well known to those skilled in the art. The first connector 46 is an optical and physical connection between the fiber bundle 42 and the output optical fiber 44, which allows light from the lasers 14, 16, 18, 20, 22, 24, 26 to be transmitted from the input optical fibers 28, 30, 32, 34, 36, 38, 40 to the output optical fiber 44. Without limiting the meaning of the term "connector", as will be understood by those skilled in the art, the connector 46 fuses the fiber bundle 42 to the output optical fiber 44 in an integral structure without a free space beam.

[0070] Light that travels through output fiber 44 exits the output fiber at distal end 48. The exiting light is represented by arrow 50 and is referred to herein as output light 50.

[0071] Further references Figure 1 It is worth noting that the optical combiner 12 of the present invention includes the output ends of the input optical fibers 28, 30, 32, 34, 36, 38, 40, the optical fiber bundle 42, the input end of the output optical fiber 44, the first connector 46 and a section of the output optical fiber 44. The dotted box depicts the optical combiner 12.

[0072] It is worth noting that the names of the structures listed in the dotted frame of the optical combiner 12 are not intended to limit the present invention. It should be obvious to those skilled in the art that modifications and substitutions can be made without departing from the scope of the present invention.

[0073] Figure 2A diagrammatic cross-sectional view of a first embodiment of an input fiber optic bundle, referred to herein as a first input fiber optic bundle 52, is shown on the left side of the figure. Figure 2 A pictorial cross-sectional view of a contemplated embodiment of output optical fiber 44 is also provided. As described above, first optical fiber bundle 52 is contemplated to be Figure 1 A first connector 46 is shown connected to the output optical fiber 44 .

[0074] Throughout Figures 2 to 9 , the graphical cross-sectional view of the output optical fiber 44 is the same. This convention is deliberately adopted to simplify the discussion of the present invention.

[0075] Output optical fiber 44 is depicted as a dual core optical fiber, meaning that optical fiber 44 includes an inner core 86 surrounded by an annular outer core 88, as discussed in more detail in the following paragraphs. For this reason, output optical fiber 44 is also referred to herein as a multi-core output optical fiber 44.

[0076] Although the output optical fibers 44 are uniformly illustrated in all figures, it is noted that the configuration of the output optical fibers 44 may vary from the depicted embodiment without departing from the scope of the present invention. For example, the output optical fibers 44 may be configured as a dual-ring (three-core) configuration, which would be applicable if the input optical fiber bundle 42 combines nineteen separate input optical fibers in a 1:6:12 arrangement (one optical fiber, surrounded by six optical fibers, which in turn are surrounded by twelve optical fibers). As should be apparent to those skilled in the art, other configurations of the output optical fibers 44 and corresponding input optical fiber bundles 42 may also be employed.

[0077] Furthermore, although the output optical fiber 44 is shown as a single structure, it is contemplated that the output optical fiber 44 may include two or more output optical fibers and / or output optical fiber segments that are spliced ​​and / or fused to one another. Fig.10 This envisioned embodiment is shown in FIG.

[0078] exist Fig.10 In the illustrated embodiment, the output optical fiber 44 has a first output optical fiber segment 44a contained within the optical combiner 12. The second output optical fiber segment 44b is located outside the optical combiner 12. The first output optical fiber segment 44a is fused to the second output optical fiber segment 44b at a second connector 47. The first output optical fiber segment 44a and the second output optical fiber segment 44b together form the output optical fiber 44.

[0079] In one non-limiting example, the first output fiber segment 44a can be identical in composition and cross-section to the second output fiber segment 44b.

[0080] In another non-limiting example, Fig.12 As shown, the second connector 47 may be a multi-core step connector 130 .

[0081] Typically, taking into account fiber manufacturing and connector alignment tolerances, a multi-core step connector (e.g., the multi-core step connector 130 discussed below) is designed so that the first optical fiber and the second optical fiber ensure that light propagating in the inner core of the first optical fiber is effectively coupled into the inner core of the second optical fiber, and light propagating in the outer core of the first optical fiber is effectively coupled into the outer core of the second optical fiber. Specifically, the dimensions and tolerances of the (fiber) core and cladding regions are specified to ensure high coupling efficiency between the inner cores and between the outer cores, wherein crosstalk or loss from any guide region is minimized. This design ensures good manufacturability and maintainability (i.e., high yield) when splicing between the first optical fiber and the second optical fiber is performed in a factory or on-site.

[0082] exist Fig.12 In the illustrated multi-core step connector 130, a first output fiber segment 132 is connected to a second output fiber segment 134. The multi-core step connector 130 allows two optical fibers 132, 134 (which are both multi-core optical fibers) to be joined to each other in a manner that manages tolerances and variations between the fiber segments 132, 134. Tolerances include, but are not limited to, dimensional tolerances and alignment tolerances associated with the fiber segments 132, 134.

[0083] exist Fig.12 In the depicted non-limiting example, the first output fiber segment 132 has a first inner core 136 surrounded by a first inner core cladding 138. The first output fiber segment 132 also has a first outer core 140 surrounded by a first outer core cladding 142. Likewise, the second output fiber segment 134 has a second inner core 144 surrounded by a second inner core cladding 146. The second output fiber segment 134 also has a second outer core 148 surrounded by a second outer core cladding 150.

[0084] To ensure that light passing through the first inner core 136 is transmitted to the second inner core 144, the diameter of the second inner core 144 is slightly larger than the diameter of the first inner core 136. Similarly, to ensure that light passing through the first outer core 140 is transmitted to the second outer core 148, the thickness of the second outer core 148 is slightly larger than the thickness of the first outer core 140, so that the first output fiber segment 132 and the second output fiber segment 134 have the same outer diameter, as shown, and the thickness of the second inner core cladding 146 is less than the thickness of the first inner core cladding 138. Similarly, the thickness of the second outer core cladding 150 is less than the thickness of the first outer core cladding 142.

[0085] Fig.12 Also included is a refractive index profile 152 of the first output fiber segment 132. The profile illustrates the refractive index n of the first core 136. a Greater than the refractive index n of the first inner core cladding 138 b Similarly, the refractive index n of the first outer core 140 is aGreater than the refractive index n of the first outer core cladding 142 b As should be apparent to those skilled in the art, refractive index profile 152 is merely exemplary. Other profiles may be employed without departing from the scope of the present invention. Furthermore, the structure of multi-core step connector 130 may be used in any position of the present invention for splicing two optical fibers together, as needed and / or desired. Further, refractive index profile 152 is considered applicable to any of the optical fibers discussed herein.

[0086] return Figure 2 , the first optical fiber bundle 52 will Figure 1 The output ends of the input optical fibers 28, 30, 32, 34, 36, 38, 40 are shown combined into a dense configuration. Specifically, in the first optical fiber bundle 52, the input optical fibers 28, 30, 32, 34, 36, 38, 40 are arranged as a central input optical fiber 28 surrounded by six lateral input optical fibers 30, 32, 34, 36, 38, 40. The central input optical fiber 28 is also referred to as the first input optical fiber 28. The six lateral input optical fibers are referred to as the second to seventh input optical fibers 30, 32, 34, 36, 38, 40. This arrangement is generally referred to as a "hexagonal dense arrangement" by those skilled in the art.

[0087] Although not intended to limit the present invention, a first input fiber 28 is connected to the first laser 14, a second input fiber 30 is connected to the second laser 16, a third input fiber 32 is connected to the third laser 18, a fourth input fiber 34 is connected to the fourth laser 20, a fifth input fiber 36 is connected to the fifth laser 22, a sixth input fiber 38 is connected to the sixth laser 24, and a seventh input fiber 40 is connected to the seventh laser 26.

[0088] exist Figure 2 In the figure, in order to more easily identify which input optical fibers 28, 30, 32, 34, 36, 38, 40 are connected to which lasers 14, 16, 18, 20, 22, 24, 26, the input optical fibers 28, 30, 32, 34, 36, 38, 40 are numbered 1-7. The numbers 1-7 correspond to the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 and the first to seventh lasers 14, 16, 18, 20, 22, 24, 26.

[0089] As should be apparent, the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are connected to the first to seventh lasers 14, 16, 18, 20, 22, 24, 26 and Figure 1 and Figure 2The first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are associated in the manner shown, but this is not intended to limit the present invention. The first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 can be arranged in any order. In addition, on the contrary, without departing from the scope of the present invention, the first to seventh lasers 14, 16, 18, 20, 22, 24, 26 can be attached to any one of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 in any applicable order.

[0090] like Figure 2 As shown, the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are contemplated to include first to seventh input optical fiber cores 54, 56, 58, 60, 62, 64, 66 surrounded by claddings designated as first to seventh input optical fiber claddings 68, 70, 72, 74, 76, 78, 80. It is contemplated that the first to seventh input optical fiber cores 54, 56, 58, 60, 62, 64, 66 have a first refractive index n1 (also referred to as a refractive index), and the first to seventh input optical fiber claddings 68, 70, 72, 74, 76, 78, 80 have a second refractive index n2 (n2) that is less than the first refractive index n1. <n1)。

[0091] In one contemplated non-limiting embodiment, each of the first through seventh input fiber cores 54, 56, 58, 60, 62, 64, 66 is contemplated to be made of the same material and, therefore, have the same first refractive index n1. Likewise, the first through seventh input fiber claddings 68, 70, 72, 74, 76, 78, 80 are contemplated to be made of the same material and have the same second refractive index n2.

[0092] It is worth noting that any of the first to seventh input fiber cores 54, 56, 58, 60, 62, 64, 66 may be made of different materials and thus may have different refractive indices from each other. Likewise, any of the first to seventh input fiber claddings 68, 70, 72, 74, 76, 78, 80 may be made of different materials so that they have different refractive indices from each other.

[0093] exist Figure 2 In the illustrated embodiment, it is contemplated that the first through seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 have the same diameter. Furthermore, it is contemplated that the first through seventh input optical fiber cores 54, 56, 58, 60, 62, 64, 66 have the same diameter. Thus, it is also contemplated that the first through seventh input optical fiber claddings 68, 70, 72, 74, 76, 78, 80 have the same thickness.

[0094] However, it is worth noting that the diameters of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40, the diameters of the first to seventh input optical fiber cores 54, 56, 58, 60, 62, 64, 66, and the diameters / thicknesses of the first to seventh input optical fiber claddings 68, 70, 72, 74, 76, 78, 80 may be varied without departing from the scope of the present invention. In addition, the diameters of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40, the diameters of the first to seventh input optical fiber cores 54, 56, 58, 60, 62, 64, 66, and the diameters / thicknesses of the first to seventh input optical fiber claddings 68, 70, 72, 74, 76, 78, 80 may be different from one another without departing from the scope of the present invention.

[0095] Without limiting the present invention, it is separately contemplated that, for example, the diameter / thickness of the first input fiber cladding 68 may be greater than the diameter / thickness of the second to seventh input fiber claddings 70, 72, 74, 76, 78, 80. This may provide some advantages, as should be apparent to one skilled in the art.

[0096] Furthermore, it is worth noting that the output optical fiber 44 and / or any of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 may have multiple claddings (e.g., two or more claddings) without departing from the scope of the present invention. Fig.13 1 shows a multi-clad fiber 152 as an example of this contemplated structure. Here, a multi-clad core 154 is surrounded by a first cladding 156. The first cladding 156 is in turn surrounded by a second cladding 158. Additional claddings may also be employed without departing from the scope of the present invention.

[0097] Continue to refer Figure 2 , the first through seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are surrounded by an optional first glass support structure 82, which may be configured as a capillary or tube disposed around the first through seventh input optical fibers 28, 30, 32, 34, 36, 38, 40. It is contemplated that the first glass support structure 82 will provide structure and support for the first through seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 disposed therein.

[0098] Alternatively, the first glass support structure 82 may be omitted without departing from the invention.

[0099] Continue to refer Figure 2, a first interstitial space 84 is established in the cylindrical channel 83 between the first glass support structure 82 and the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40. In this embodiment, the first interstitial space 84 is a cylindrical space (circular in cross section). It is contemplated that the first interstitial space 84 in the cylindrical channel 83 is filled with air. However, the first interstitial space 84 may be filled with any other material without departing from the scope of the present invention.

[0100] Another non-limiting example of the fifth optical fiber bundle 128 is shown at Fig.11 The fifth optical fiber bundle 128 is conceived to be similar to the first optical fiber bundle 52 in that the first through seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are arranged in a close-packed hexagonal configuration.

[0101] In the fifth optical fiber bundle 128, there is no gap space 84 between the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40. Here, the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 are disposed within a glass and / or fused silica carrier 84a. In a variation of the fifth optical fiber bundle 128, the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 may be fused to each other, thereby also avoiding a structure having any gap space 84.

[0102] As should be apparent to one skilled in the art, other configurations of the fifth optical fiber bundle 128 are possible without departing from the scope of the present invention.

[0103] return Figure 2 , the output optical fiber 44 is depicted on the right side of the illustration.

[0104] The output fiber 44 is a multi-core output fiber 44 that includes an inner core 86 surrounded by an outer core 88. The inner core 86 is surrounded by an inner core cladding 90. Likewise, the outer core 88 is surrounded by an outer core cladding 92. The outer core cladding is surrounded by an (optional) output fiber glass support structure 94 that is similar to the first glass support structure 82 described above.

[0105] In a non-limiting example, it is contemplated that the inner core 86 and the outer core 88 will be made of the same material so that the inner core 86 and the outer core 88 have the same refractive index. Here, in order to distinguish the refractive index of the inner core 86 and the outer core 88 from the first refractive index n1 and the second refractive index n2 discussed in conjunction with the first optical fiber bundle 52, the refractive index of the inner core 86 and the outer core 88 is referred to as a third refractive index n3.

[0106] This structure of output optical fiber 44 is not intended to be limiting of the present invention.Inner core 86 may be made of a different material than outer core 88, such that the inner and outer cores do not share the same third refractive index n3.

[0107] In this same non-limiting example, it is contemplated that the inner core cladding 90 and the outer core cladding 92 will be made of the same material, such that the inner core cladding 90 and the outer core cladding 92 have the same refractive index. Here, in order to distinguish the refractive index of the inner core cladding 90 and the outer core cladding 92 (i.e., the first refractive index n1, the second refractive index n2, and the third refractive index n3 described above), the refractive index of the inner core cladding 90 and the outer core cladding 92 is referred to as a fourth refractive index n4. As should be apparent to those skilled in the art, the fourth refractive index n4 is contemplated to be less than the third refractive index n3 (n4 <n3)。

[0108] In an alternative configuration, the inner core cladding 90 may be made of a different material than the outer core cladding 92, such that the inner core cladding and the outer core cladding do not share the same fourth refractive index n4.

[0109] like Figure 2 As shown, the first fiber bundle 52 is configured with a first fiber bundle diameter 96. The output fiber 44 is configured with an output fiber diameter 98. In the illustrated embodiment, the first fiber bundle diameter 96 is the same as the output fiber diameter 98. However, this configuration is not intended to limit the present invention. The first fiber bundle diameter 96 can be smaller than the output fiber diameter 98. Alternatively, it is contemplated that the output fiber diameter 98 can be smaller than the first fiber bundle diameter 96.

[0110] Figure 3 yes Figure 2 A combined pictorial cross-sectional view of a first embodiment of an input fiber bundle 52 and an output optical fiber 44 is shown.

[0111] When spliced ​​together at the first connector 46, it is contemplated that the first input optical fiber 28 in the input optical fiber bundle 52 will be aligned with the inner core 86 of the output optical fiber 44. Also, it is contemplated that the second through seventh input optical fibers 30, 32, 34, 36, 48, 40 will be aligned with the outer core 88 of the output optical fiber 44 as shown.

[0112] In another non-limiting embodiment, multiple input optical fibers may be registered with the inner core 86 without departing from the scope of the present invention.

[0113] When the first optical fiber bundle 52 and the output optical fiber 44 are connected Figure 3When spliced ​​together in the manner shown, light from the first laser 14 passes through the first input fiber 28 and is guided or coupled into the inner core 86 of the output fiber 44. Similarly, light from one or more of the second to seventh lasers 16, 18, 20, 22, 24, 26 passes through the corresponding input fiber of the second to seventh input fibers 30, 32, 34, 36, 38, 40 and is guided or coupled into the outer core 88. The light that passes through the inner core 86 and the outer core 88 is emitted from the output fiber 44 as output light 50.

[0114] Figure 4 A diagrammatic cross-sectional view of a second embodiment of an input fiber bundle 100 and a diagrammatic cross-sectional view of an output fiber 44 are shown. Figure 2 and Figure 3 As with the illustrated embodiment, the second fiber bundle 100 and the output fiber 44 are contemplated to be coupled to each other in the optical combiner 12 of the present invention.

[0115] As is apparent from this figure, the structure of the second fiber optic bundle 100 differs from the first fiber optic bundle 52 in several respects.

[0116] In this second embodiment, the second optical fiber bundle 100 includes only three input optical fibers, namely the first input optical fiber 28, the second input optical fiber 30, and the fifth input optical fiber 36. As should be apparent, these three specific input optical fibers are shown here because these three specific input optical fibers are consistent with the position orientation of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 in the first optical fiber bundle 52. However, the present invention is not limited to this choice. Without departing from the scope of the present invention, any three input optical fibers of the first to seventh input optical fibers 28, 30, 32, 34, 36, 38, 40 can be used as the three input optical fibers in the second optical fiber bundle 100.

[0117] In the second optical fiber bundle 100, the input optical fibers 28, 30, 36 are arranged in a linear manner within the second optical fiber bundle 100. In this way, the input optical fibers 28, 30, 36 are disposed in a rectangular channel 102, which defines a rectangular second gap space 104 within the second optical fiber bundle 100. Here, the second glass support structure 106 is configured to define the rectangular channel 102 and the second gap space 104. It is worth noting that the channel 102 can have any other shape besides a rectangle without departing from the scope of the present invention. For example, the channel 102 can be oval, elliptical, etc.

[0118] like Figure 4 As shown, the output optical fiber 44 is constructed in the same manner as previously described.

[0119] In the second embodiment, the second fiber bundle 100 has a second fiber bundle diameter 106. The second fiber bundle diameter 106 is the same as the output fiber diameter 98 of the output optical fiber 44.

[0120] Figure 5 is a combined pictorial cross-sectional view of a second embodiment of a second input fiber bundle 100 and an output optical fiber 44.

[0121] As shown, the second input fiber bundle 100 is spliced ​​to the output fiber 44 such that the first input fiber 28 is aligned with the inner core 86 of the output fiber 44. In the second embodiment, the second input fiber 30 and the fifth input fiber 36 are aligned with the outer core 88. As a result, light from the first laser 14 passes through the first input fiber 28 and is guided or coupled into the inner core 86 of the output fiber 44. Light from the second input fiber 30 and the fifth input fiber 36 is guided or coupled into the outer core 88. As in the first embodiment, light that passes through the inner core 86 and the outer core 88 is emitted from the output fiber 44 as output light 50.

[0122] Figure 6 There is shown a diagrammatic cross-sectional view of a third embodiment of third fiber bundle 108 and a diagrammatic cross-sectional view of output fiber 44. As with the first and second embodiments discussed above, third fiber bundle 108 and output fiber 44 are contemplated to be coupled to one another in optical combiner 12 of the present invention.

[0123] The structure of the third fiber optic bundle 108 differs from the first fiber optic bundle 52 and the second fiber optic bundle 100 in several respects.

[0124] In this third embodiment, the third fiber bundle 108 includes only three input optical fibers, namely, the first input optical fiber 28, the second input optical fiber 30, and the third input optical fiber 32. As in the discussion of the second fiber bundle 100, the first input optical fiber 28, the second input optical fiber 30, and the third input optical fiber 32 have been selected because their respective positional orientations are consistent with the orientations of the first input optical fiber 28, the second input optical fiber 30, and the third input optical fiber 32 shown in conjunction with the first fiber bundle 52.

[0125] As discussed in conjunction with the second fiber bundle 100, the present invention should not be construed as limited to relying only on the first input fiber 28, the second input fiber 30, and the third input fiber 32. Any of the first through seventh input fibers 28, 30, 32, 34, 36, 38, 40 may be employed without departing from the scope of the present invention.

[0126] In the third optical fiber bundle 108, the input optical fibers 28, 30, 32 are arranged in a dense configuration, wherein the three input optical fibers 28, 20, 32 are arranged in a triangular pattern. The three input optical fibers 28, 30, 32 are combined into a twisted bundle, which causes the three input optical fibers 28, 30, 32 to be wound together in a spiral manner. The three input optical fibers 28, 30, 32 are arranged in a cylindrical channel 110 (similar to the cylindrical channel arranged in the first optical fiber bundle 52). A third interstitial space 112 is defined within the cylindrical channel 110.

[0127] Unlike the first fiber bundle 52, since the first fiber bundle 52 only includes three input optical fibers 28, 30, 32, the cylindrical channel 110 has a smaller diameter, and therefore the third glass support structure 114 has a third fiber bundle diameter 116 that is smaller than the first fiber bundle diameter 96 or the second fiber bundle diameter 106. As shown, the third fiber bundle diameter 116 is also smaller than the output fiber diameter 98. However, the configuration shown should not be construed as limiting the present invention. The dimensions of the third glass support structure 114 can be set so that the third fiber bundle diameter 116 is equal to or greater than the output fiber diameter 98.

[0128] like Figure 6 As shown, the output optical fiber 44 is constructed in the same manner as previously described.

[0129] Figure 7 is a combined pictorial cross-sectional view of a second embodiment of the third input fiber bundle 108 and the output optical fiber 44.

[0130] Here, because the first input fiber 28 is not at the center of the third input fiber bundle 108, and because the input fibers 28, 30, 32 are not arranged linearly, the center of the third fiber bundle 108 is offset relative to the center of the output fiber 44 when they are spliced ​​together. However, as previously described, the first input fiber 28 is aligned with the inner core 86 of the output fiber 44. In this third embodiment, the second input fiber 30 and the third input fiber 32 are aligned with the outer core 88. As a result, light from the first laser 14 passes through the first input fiber 28 and is guided or coupled into the inner core 86 of the output fiber 44. Light from the second input fiber 30 and the third input fiber 32 is guided or coupled into the outer core 88.

[0131] As in the first and second embodiments, light that passes through the inner core 86 and the outer core 88 is emitted from the output optical fiber 44 as output light 50 .

[0132] Figure 8There is shown a diagrammatic cross-sectional view of the fourth fiber bundle 118 and a diagrammatic cross-sectional view of the output optical fiber 44. As previously mentioned, the fourth fiber bundle 118 and the output optical fiber 44 are contemplated to be coupled to each other in the optical combiner 12 of the present invention.

[0133] The fourth fiber optic bundle 118 differs from the first fiber optic bundle 52 , the second fiber optic bundle 100 , and the third fiber optic bundle 108 in several respects.

[0134] Although the fourth fiber bundle 118 also relies on the first input fiber 28, the second input fiber 30, and the third input fiber 32 to provide light from the first to third lasers 14, 16, 18 to the output fiber 44, the fourth fiber bundle 118 incorporates an offset cylindrical channel 120 surrounding the first input fiber 28, the second input fiber 30, and the third input fiber 32. The offset cylindrical channel 120 defines a fourth interstitial space 122 surrounding the first input fiber 28, the second input fiber 30, and the third input fiber 32.

[0135] As from Figure 8 and Fig. 9 As is apparent from the diagram, the fourth glass support structure 124 does not have a uniform thickness due to the offset placement of the offset cylindrical channel 120. In this embodiment, the fourth fiber bundle 118 has a fourth fiber bundle diameter 126 that is smaller than the output fiber diameter 98 but larger than the third fiber bundle diameter 116. As with the other embodiments, the configuration shown should not be construed as limiting the present invention. The dimensions of the fourth glass support structure 124 can be designed such that the fourth fiber bundle diameter 126 is equal to or larger than the output fiber diameter 98.

[0136] Fig. 9 is a combined pictorial cross-sectional view of the fourth input fiber bundle 118 and the output optical fiber 44.

[0137] As with the third fiber bundle 108, the manner in which the fourth fiber bundle 118 is spliced ​​to the output fiber 44 is slightly more complex than in the first or second embodiments. However, as previously described, the first input fiber 28 is aligned with the inner core 86 of the output fiber 44. In this fourth embodiment, the second input fiber 30 and the third input fiber 32 are aligned with the outer core 88. As a result, light from the first laser 14 passes through the first input fiber 28 and is guided or coupled into the inner core 86 of the output fiber 44. Light from the second input fiber 30 and the third input fiber 32 is guided or coupled into the outer core 88.

[0138] As in the first, second, and third embodiments, light that passes through the inner core 86 and the outer core 88 is emitted from the output optical fiber 44 as output light 50 .

[0139] As described above, the embodiments of the present invention are exemplary only and are not intended to limit the present invention. Features from one embodiment may be interchangeable with other embodiments, as should be apparent to those skilled in the art. Therefore, variations and equivalents of the embodiments described herein are intended to fall within the scope of the appended claims.

Claims

1. A photosynthetic combiner, comprising: an optical fiber bundle, the optical fiber bundle comprising a plurality of input optical fibers; an output optical fiber comprising an inner core surrounded by an outer core; a connector, the connector fusing the optical fiber bundle to the output optical fiber; at least a first input optical fiber from the plurality of input optical fibers, the at least first input optical fiber being aligned and registered with the inner core; as well as At least a second input optical fiber from the plurality of input optical fibers is aligned and registered with the outer core.

2. The optical combiner according to claim 1, wherein: At least one of the plurality of input optical fibers includes a plurality of claddings.

3. The optical combiner according to claim 1, wherein: The output optical fiber includes a plurality of claddings.

4. The optical combiner according to claim 1, wherein: The plurality of input optical fibers include: The first input optical fiber, the second input optical fiber, the third input optical fiber, the fourth input optical fiber, the fifth input optical fiber, the sixth input optical fiber and the seventh input optical fiber.

5. The optical combiner according to claim 4, wherein: The first input fiber is surrounded by the second input fiber, the third input fiber, the fourth input fiber, the fifth input fiber, the sixth input fiber, and the seventh input fiber.

6. The optical combiner according to claim 5, wherein: The third input fiber, the fourth input fiber, the fifth input fiber, the sixth input fiber, and the seventh input fiber are also aligned and registered with the outer core.

7. The optical combiner according to claim 1, wherein: The plurality of input optical fibers include: The first input optical fiber, the second input optical fiber and the third input optical fiber.

8. The optical combiner according to claim 7, wherein: The first input optical fiber is disposed adjacent the second input optical fiber and the third input optical fiber in a linear configuration.

9. The optical combiner according to claim 8, wherein: The second input optical fiber and the third input optical fiber are aligned and registered with the outer core.

10. The optical combiner according to claim 7, wherein: The first input optical fiber is disposed adjacent to the second input optical fiber and the third input optical fiber in a triangular configuration.

11. The optical combiner according to claim 10, wherein: The third input optical fiber is also aligned with the outer core.

12. The optical combiner according to claim 1, wherein: The optical combiner also includes: A glass support structure, wherein the plurality of input optical fibers are disposed in the glass support structure.

13. The optical combiner according to claim 1, wherein: The output optical fiber comprises: A first output optical fiber segment is fused to a second output optical fiber segment at a second splice.

14. The optical combiner according to claim 13, wherein: The second joint is a multi-core step joint.

15. A laser system comprising: a plurality of lasers that generate laser light; as well as An optical combiner, the optical combiner being connected to the plurality of lasers, wherein the optical combiner comprises: a fiber optic bundle comprising a plurality of input optical fibers receiving the laser light from the plurality of lasers; an output optical fiber comprising an inner core surrounded by an outer core that receives the laser light from the optical fiber bundle; a connector, the connector fusing the optical fiber bundle to the output optical fiber; at least a first input optical fiber from the plurality of input optical fibers, the at least first input optical fiber being aligned and registered with the inner core; and At least a second input optical fiber from the plurality of input optical fibers is aligned and registered with the outer core.

16. The laser system of claim 15, wherein: At least one of the plurality of input optical fibers includes a plurality of claddings.

17. The laser system of claim 15, wherein: The output optical fiber includes a plurality of claddings.

18. The laser system of claim 15, wherein: The plurality of input optical fibers include the first input optical fiber, the second input optical fiber, the third input optical fiber, the fourth input optical fiber, the fifth input optical fiber, the sixth input optical fiber and the seventh input optical fiber, a first laser from the plurality of lasers provides light to the first input optical fiber, and At least a second laser from the plurality of lasers provides light to at least the second input optical fiber.

19. The laser system of claim 18, wherein: The first input fiber is surrounded by the second input fiber, the third input fiber, the fourth input fiber, the fifth input fiber, the sixth input fiber, and the seventh input fiber.

20. The laser system of claim 19, wherein: The third input fiber, the fourth input fiber, the fifth input fiber, the sixth input fiber, and the seventh input fiber are also aligned and registered with the outer core.

21. The laser system of claim 15, wherein: The plurality of input optical fibers include the first input optical fiber, the second input optical fiber and the third input optical fiber, a first laser from the plurality of lasers provides light to the first input optical fiber, and At least a second laser from the plurality of lasers provides light to at least the second input optical fiber.

22. The laser system of claim 21, wherein: The first input optical fiber is disposed adjacent the second input optical fiber and the third input optical fiber in a linear configuration.

23. The laser system of claim 22, wherein: The third input optical fiber is also aligned with the outer core.

24. The laser system of claim 21, wherein: The first input optical fiber is disposed adjacent to the second input optical fiber and the third input optical fiber in a triangular configuration.

25. The laser system of claim 24, wherein: The third input optical fiber is also aligned with the outer core.

26. The laser system of claim 15, wherein: The laser system further comprises: A glass support structure, wherein the plurality of input optical fibers are disposed in the glass support structure.

27. The laser system of claim 15, wherein: The output optical fiber comprises: A first output optical fiber segment is fused to a second output optical fiber segment at a second splice.

28. The laser system of claim 27, wherein: The second joint is a multi-core step joint.

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