Stray light stripper for combiner

Abstract

The invention relates to a stray light stripper for a combiner. In some implementations, an optical fiber combiner includes a glass tube. A stray light stripper may be defined at a surface of the glass tube. The stray light stripper may be defined by perturbations in the surface of the glass tube or a layer of material on the glass tube having a different refractive index than the refractive index of the glass tube. The perturbations may be grooves, notches, or etches. The optical fiber combiner may include an optical fiber bundle disposed within a glass tube, the optical fiber bundle including a plurality of optical fibers.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This patent application claims priority to U.S. Provisional Patent Application No. 63 / 590,585, filed on October 16, 2023, entitled “STRAY LIGHT STRIPPERFOR A GLASS TUBE”. The disclosure of that prior application is considered a part of this patent application and is incorporated by reference into this patent application. Technical Field

[0003] The present invention generally relates to fiber lasers and stray light strippers for combiners. Background Art

[0004] Pump combiners and pump-signal combiners are important components of high-power fiber lasers. Pump combiners or pump-signal combiners combine the light input into the fiber to increase the total power of the light emitted by the fiber laser. Summary of the invention

[0005] In some implementations, an optical system includes a fiber oscillator or a fiber amplifier. The optical system may include an input system, the input system including a plurality of laser sources. The plurality of laser sources may include at least one of one or more first laser sources configured to generate signal light or one or more second laser sources configured to generate pump light. The optical system may include an output fiber optically coupled to the fiber oscillator or the fiber amplifier, the output fiber including one or more cores configured to carry signal light and a cladding surrounding the one or more cores configured to carry pump light. The optical system may include a fiber combiner arranged between the input system and the output fiber, the fiber combiner including a glass tube, wherein a stray light stripper is defined at a surface of the glass tube. The fiber combiner may include a fiber bundle disposed within the glass tube, the fiber bundle including a plurality of optical fibers.

[0006] In some implementations, the optical system includes a fiber oscillator and a fiber amplifier, wherein the fiber combiner is a first fiber combiner optically coupled to the fiber oscillator, and wherein the optical system further includes a second fiber combiner optically coupled to the fiber amplifier.

[0007] In some implementations, the plurality of laser sources includes at least one first laser source configured to generate signal light and at least one second laser source configured to generate pump light.

[0008] In some implementations, the plurality of laser sources includes a plurality of second laser sources configured to generate pump light.

[0009] In some implementations, the plurality of laser sources includes a plurality of first laser sources configured to generate signal light.

[0010] In some implementations, the stray light stripper is defined by a chemical etch in the surface of the glass tube or a groove in the surface of the glass tube.

[0011] In some implementations, the stray light stripper is configured to strip the stray light in the glass tube without stripping the pump light in the glass tube.

[0012] In some implementations, a fiber combiner is disposed between the input system and the output fiber in a counter-pumping configuration.

[0013] In some implementations, a fiber combiner includes a glass tube. A stray light stripper may be defined at a surface of the glass tube. The stray light stripper may be defined by a disturbance in the surface of the glass tube or a material on the glass tube having a refractive index different from that of the glass tube. The disturbance may be a groove, a notch, or an etched portion. The fiber combiner may include a fiber bundle disposed within the glass tube, the fiber bundle including a plurality of optical fibers.

[0014] In some implementations, the plurality of optical fibers includes one or more signal optical fibers and one or more pump optical fibers.

[0015] In some implementations, the plurality of optical fibers includes a plurality of pump fibers.

[0016] In some implementations, the plurality of optical fibers includes a plurality of signal optical fibers.

[0017] In some implementations, the perturbation is a chemical etch.

[0018] In some implementations, the perturbations are grooves in a sawtooth pattern.

[0019] In some implementations, the stray light stripper is defined at a non-tapered portion of the glass tube.

[0020] In some implementations, the stray light stripper is defined at a non-tapered portion of the glass tube and at a tapered portion of the glass tube.

[0021] In some implementations, the perturbation includes: a first row of grooves presenting a zigzag pattern centered at a 0° position relative to the circumference of the glass tube; a second row of grooves presenting a zigzag pattern centered at a 90° position relative to the circumference of the glass tube; a third row of grooves presenting a zigzag pattern centered at a 180° position relative to the circumference of the glass tube; and a fourth row of grooves presenting a zigzag pattern centered at a 270° position relative to the circumference of the glass tube.

[0022] In some implementations, a method includes forming a stray light stripper on a glass tube, inserting an optical fiber bundle into the glass tube, wherein the optical fiber bundle includes a plurality of optical fibers, tapering a portion of the glass tube and a portion of the optical fiber bundle disposed within the glass tube, cutting the optical fiber bundle, and splicing the optical fiber bundle to an output optical fiber.

[0023] In some implementations, forming the stray light stripper includes etching a surface of the glass tube using a chemical etching process.

[0024] In some implementations, forming the stray light stripper includes using laser ablation to form grooves or notches in a surface of the glass tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is a cross-sectional view of an example combiner.

[0026] Figure 2 An example combiner is illustrated.

[0027] Figure 3 is a top view of a portion of a glass tube with a stray light stripper.

[0028] Figure 4 is a top view of a portion of a glass tube with a stray light stripper.

[0029] Figure 5 An example optical system is illustrated.

[0030] Figure 6 is a flow diagram of an example process associated with fabrication of a combiner. DETAILED DESCRIPTION

[0031] The following detailed description of example implementations refers to the accompanying drawings.The same reference numbers in different drawings may identify the same or similar elements.

[0032] Combiners (such as pump combiners and pump-signal combiners) are important components of high-power fiber lasers. For example, a pump combiner typically combines pump light to produce a combined pump light with increased power. In many cases, the pump combiner is arranged in a beam configuration that is joined to another optical structure (e.g., a master oscillator power amplifier (MOPA) and / or a single-pass fiber laser structure) that is configured to deliver hundreds of watts (W) / kilowatts (kW) of pump power. The beam configuration can be achieved by arranging the pump fibers into a specific close-packed configuration (e.g., a hexagonal close-packed configuration, etc.) and melting and tapering the individual pump fibers into a beam of a target size. In addition, in a pump-signal combiner, a signal fiber is included in the bundle together with the individual pump fibers. In this way, various pump fibers can be used to couple pump power from multiple pump sources into the cladding of an output fiber, and the signal light can propagate through the core of the signal fiber included in the pump-signal combiner into the core of the output fiber. By enclosing the bundle in a glass tube, stable and efficient packaging of the optical fiber bundle can be achieved. Without using a glass tube, the number of optical fibers in the bundle and / or the arrangement of the optical fibers in the bundle may have constraints that are not imposed when using a glass tube.

[0033] A combiner using a glass tube can be included in a high-power fiber laser system in a reverse pumping configuration or a forward pumping configuration. In the reverse pumping configuration, a considerable amount of the forward propagating light of the system can propagate into the fiber bundle of the combiner. The light in the fiber cladding may then enter the glass tube as undesirable stray light. In the forward pumping configuration, the backward propagating light of the system may similarly enter the glass tube as stray light due to backward amplified spontaneous emission (ASE), backward stimulated Raman scattering (SRS), backward stimulated Brillouin scattering (SBS), back reflection, etc. The stray light in the glass tube may cause excessive heating of the combiner, which may damage the fiber coating and / or the adhesive used to package the bundle in the glass tube. Damage to the combiner may cause the performance of the high-power fiber laser system to be impaired.

[0034] Some implementations described herein provide a stray light stripper on a glass tube of a combiner (e.g., a pump combiner, a pump-signal combiner, or a signal combiner). The stray light stripper can be defined by a perturbation in the surface of the glass tube, such as a groove, a notch, or an etching. Additionally or alternatively, the stray light stripper can be defined by a layer of material applied to the glass tube having a refractive index different from that of the glass tube. The stray light stripper allows stray light in the glass tube to escape and scatter from the glass tube. In this way, overheating and damage to the combiner can be avoided, thereby improving the performance and service life of the combiner, as well as improving the performance of a high power (e.g., multi-kilowatt) fiber laser system that includes the combiner.

[0035] Figure 1 is a cross-sectional view of example combiners 100, 120, and 140. As described herein, combiners 100, 120, and 140 can be used to scale power in multi-kilowatt fiber lasers. Combiners 100, 120, and 140 can be fiber combiners. Combiner 100 is shown as a pump combiner, combiner 120 is shown as a pump-signal combiner, and combiner 140 is shown as a signal combiner. Each combiner 100, 120, and 140 may include an enclosing tube 102 (e.g., a glass tube, a capillary, etc.) containing a fiber bundle 104. The fiber bundle 104 of combiner 100 may include a plurality of pump fibers 106 (shown as a 7×1 pump combiner). The fiber bundle 104 of combiner 120 may include a signal fiber 108 surrounded by a plurality of pump fibers 106 (shown as a (6+1)×1 pump-signal combiner). The fiber bundle 104 of the combiner 140 may include a plurality of signal fibers 108 (shown as a 7x1 signal combiner). Using the confining tube 102, there may be nearly any number of pump ports and / or signal ports in the combiner.

[0036] In some implementations, a combiner (e.g., combiner 100, 120, or 140) can be manufactured by fusing several optical fibers into a fiber bundle 104, packaging the fiber bundle 104 into a confining tube 102, and collapsing the confining tube 102 onto the fiber bundle 104. For example, the optical fibers of the fiber bundle 104 can be packaged into the confining tube 102, and then the assembly can be fused and tapered. The diameter of the fused and tapered assembly can be matched to the diameter size of the core of the output optical fiber. The combiner bundle and the output optical fiber can then be spliced ​​to complete the combiner.

[0037] As mentioned above, Figure 1 are provided as examples. Other examples can be found in the Figure 1 Different from what is described.

[0038] Figure 2 An example combiner 200 is shown. The combiner 200 is a fiber optic combiner. The combiner 200 is Figure 2 However, in some implementations, combiner 200 may be a pump combiner or a signal combiner.

[0039] like Figure 2As shown, the combiner 200 may include a fiber bundle 205 (e.g., corresponding to the fiber bundle 104). The fiber bundle 205 includes a plurality of optical fibers 210, 220. For example, the fiber bundle 205 may include one or more pump fibers 210 and / or one or more signal fibers 220. As shown, the fiber bundle 205 includes a plurality of pump fibers 210 surrounding a signal fiber 220. In some implementations, the fiber bundle 205 may include a plurality of pump fibers 210 without a signal fiber 220. In some implementations, the fiber bundle 205 may include a plurality of signal fibers 220 without a pump fiber 210. The (plurality) pump fibers 210 may be arranged or configured to receive pump light from a corresponding pump light source (not shown). The (plurality) signal fibers 220 may be arranged or configured to receive signal light from a corresponding signal light source (not shown).

[0040] In some implementations, the pump fiber 210 and the signal fiber 220 may each include a fiber core circumferentially surrounded by a fiber cladding. Alternatively, in some implementations, the signal fiber 220 may not have a fiber cladding (e.g., the signal fiber 200 may only have a fiber core), or the signal fiber 220 may have a fiber cladding having a fiber cladding thickness different from a corresponding fiber cladding thickness of the fiber cladding of the pump fiber 210. For example, the signal fiber 220 may have a fiber cladding having a fiber cladding thickness less than a corresponding fiber cladding thickness of the fiber cladding of the pump fiber 210.

[0041] like Figure 2 As further shown, the combiner 200 may include a glass tube 230 (e.g., corresponding to the surrounding tube 102). For example, the glass tube 230 may be a capillary tube (e.g., a hollow, open-ended glass tube). The glass tube 230 may have a circular cross-section. The optical fiber bundle 205 may be disposed within the glass tube 230. For example, the interior region of the glass tube 230 may be defined by a space within the glass tube 230, such as a space between the inner surfaces of one or more walls of the glass tube 230. Thus, the optical fiber bundle 205 may be disposed within the interior region of the glass tube 230 (e.g., the optical fiber bundle 215 may be inserted into and may fill (or substantially fill) the interior region of the glass tube 230). In addition, the combiner 200 may be coupled to an output optical fiber 240. The output optical fiber may include one or more cores configured to carry signal light, and a cladding surrounding the one or more cores configured to carry pump light.

[0042] In some implementations, the pump fiber 210, the signal fiber 220, the glass tube 230, and the output fiber 240 can each include glass (e.g., silica-based glass, silica-based glass, fluoride glass, or another type of glass). In some implementations, the pump fiber 210, the signal fiber 220, the glass tube 230, and the output fiber 240 can include the same glass type or different glass types.

[0043] As described above, light propagating into the optical fibers 210, 220 via the output optical fiber 240 (e.g., in a direction opposite to the light propagation direction of the combiner 200) can generate cladding light that can enter the glass tube 230. In some implementations, the stray light stripper 250 can be defined at a surface of the glass tube 230. The surface can be an inner surface and / or an outer surface of the glass tube 230. In some examples, the stray light stripper 250 can be formed before the optical fiber bundle 205 is inserted into the glass tube 230. For example, the stray light stripper 250 can be formed at a surface of the glass tube 230, and then the optical fiber bundle 205 can be inserted into the glass tube 230.

[0044] The stray light stripper 250 may be configured to strip stray light in the glass tube 230. For example, the stray light stripper 250 may be configured to strip stray light in the glass tube 230 without stripping pump light in the glass tube 220 (e.g., the stray light stripper 250 may be configured to selectively strip stray light in the glass tube 230). When the combiner 200 is used in a reverse pumping configuration, forward propagating light may propagate into the glass tube 230 and become stray light. When the combiner 200 is used in a forward pumping configuration, reverse propagating light (e.g., due to reverse ASE, reverse SRS, reverse SBS, reverse reflection, etc.) may propagate into the glass tube 230 and become stray light. "Stripping" light from the glass tube 230 means allowing the light to escape from the glass tube 230.

[0045] The stray light stripper 250 may be defined over the entire surface of the glass tube 230, or over a region (e.g., less than the entire surface) of the surface of the glass tube 230. As shown, the glass tube 230 may be tapered, which corresponds to the taper of the optical fiber bundle 205. The stray light stripper 250 may be defined at the non-tapered portion 230-1 of the glass tube 230 and / or the tapered portion 230-2 of the glass tube 230. For example, the stray light stripper 250 may be defined only at the non-tapered portion 230-1, or at both the non-tapered portion 230-1 and the tapered portion 230-2.

[0046] As an example, for a signal combiner, the stray light stripper 250 may be defined anywhere on the surface of the glass tube 230 (e.g., because the signal light is not intended to be guided in the glass tube). For a pump combiner or a pump-signal combiner, the stray light stripper 250 may be defined anywhere on the surface of the non-tapered portion 230-1 of the glass tube 230 and / or at the beginning of the tapered portion 230-2 of the glass tube 230 (e.g., where the pump light does not leak into the glass tube 230). In other words, the pump light may leak into the portion of the glass tube 230 where the pump light is guided by the glass tube 230, and the stray light stripper 250 may be defined anywhere on the surface of the glass tube 230 except for the portion where the pump light is guided. As the pump fiber 210 is tapered, the numerical aperture of the light will increase, and high numerical aperture light (e.g., above a threshold) will escape from the pump fiber 210 and leak into the glass tube 230 (e.g., the stray light stripper 250 can be located at a position where the numerical aperture is below the threshold associated with pump light leakage into the glass tube 230).

[0047] In some implementations, the stray light stripper 250 can be defined by a perturbation in the surface of the glass tube 230. The perturbation can be a groove, notch, etching, or other irregularity in the surface of the glass tube 230. Additionally or alternatively, the perturbation can be a taper or other angular feature in the surface of the glass tube 230 (e.g., resulting from mechanical polishing of the glass tube 230).

[0048] The grooves and / or notches in the surface of the glass tube 230 may be produced using laser ablation (e.g., CO2 laser ablation) on the glass tube 230. In some implementations, the grooves and / or notches may extend continuously around the circumference of the glass tube 230. In some implementations, the grooves and / or notches may be arranged in one or more rows (e.g., where a "row" of grooves or notches refers to a sequence or pattern of grooves or notches extending linearly and longitudinally along the surface of the glass tube 230). In some implementations, the multiple rows of grooves and / or notches may be located at different positions around the circumference of the glass tube 230. For example, the stray light stripper 250 may include multiple rows of grooves and / or notches, wherein the first row is centered at a 0° position relative to the circumference of the glass tube 230, the second row is centered at a 90° position relative to the circumference of the glass tube 230, the third row is centered at a 180° position relative to the circumference of the glass tube 230, and the fourth row is centered at a 270° position relative to the circumference of the glass tube 230. In some implementations, a row of grooves and / or notches can include straight lines, curves, and / or dots, etc. In some implementations, the grooves in the surface of the glass tube 230 can have a sawtooth (eg, oscillating, sinusoidal, etc.) pattern.

[0049] The etched portion in the surface of the glass tube 230 may be a chemical etched portion. For example, the etched portion in the surface of the glass tube 230 may be produced using chemical etching. The etched portion may have a regular pattern or a random pattern.

[0050] In some implementations, the stray light stripper 250 can be defined by a layer of material on the glass tube 230. The layer of material can have a refractive index different from that of the glass tube 230. For example, the layer of material has a refractive index that can be higher than that of the glass tube 230. The material can be a type of glass (e.g., a different type of glass than that of the glass tube 230) or a polymer.

[0051] As mentioned above, Figure 2 are provided as examples. Other examples can be found in the Figure 2 Different from what is described.

[0052] Figure 3 2 is a top view of a portion of a glass tube 230 having a stray light stripper 250. As shown, the stray light stripper 250 may include a plurality of rows of grooves 252 in a surface of the glass tube 230. As described herein, each row of grooves 252 may have a zigzag pattern. The stray light stripper 250 may include a first row of grooves 252 and a second row of grooves 252 located on opposite sides of the glass tube 230, and a third row of grooves 252 and a fourth row of grooves 252 located on opposite sides of the glass tube 230 (e.g., centered at 0°, 90°, 180°, and 270° relative to the circumference of the glass tube 230, respectively).

[0053] As mentioned above, Figure 3 are provided as examples. Other examples can be found in the Figure 3 Different from what is described.

[0054] Figure 4 2 is a top view of a portion of a glass tube 230 having a stray light stripper 250. As shown, the stray light stripper 250 may include an etched portion located in the surface of the glass tube 230, which may be produced using chemical etching. The stray light stripper 250 may include a continuous etched region or a plurality of discrete etched regions. In some implementations, the etched region may extend around the circumference of the glass tube 230.

[0055] As mentioned above, Figure 4 are provided as examples. Other examples can be found in the Figure 4 Different from what is described.

[0056] Figure 5An example optical system 500 is illustrated. The optical system 500 can be a fiber laser system and / or a fiber amplifier system. For example, the optical system 500 can be a high power (e.g., multi-kilowatt) fiber laser system. In some implementations, the optical system 500 can include a master oscillator power amplifier (MOPA) configuration.

[0057] The optical system 500 may include active components (e.g., that generate optical gain and / or optical amplification). For example, the active components may include a fiber oscillator 510 and / or a fiber amplifier 515 (e.g., one or more fiber amplifiers 515). In the illustrated example, the optical system 500 includes a fiber oscillator 510 and a subsequent fiber amplifier 515 in the direction of light propagation of the optical system 500. The fiber oscillator 510 may include an active fiber. For example, the core of the active fiber may be doped with rare earth ions, such as ytterbium ions and / or erbium ions. The active fiber may be arranged between a fiber Bragg grating (e.g., at an input end of the active fiber and an output end of the active fiber), and the fiber Bragg grating forms an optical cavity (i.e., an optical resonator) with the active fiber (e.g., for generating laser light). As described above, the fiber amplifier 515 may also include an active fiber (e.g., it is not part of the optical cavity).

[0058] like Figure 5 As further shown, the optical system 500 may include one or more groups of laser sources 520 and / or laser outputs 525. For example, each group of laser sources 520 may define an input system of the optical system 500. In addition, each group of laser sources 520 may include multiple laser sources. The multiple laser sources in a group of laser sources 520 may include one or more first laser sources configured to generate signal light and / or one or more second laser sources configured to generate pump light. For example, a group of laser sources 520 may include at least one first laser source configured to generate signal light, and at least one second laser source configured to generate pump light. As another example, a group of laser sources 520 may include multiple second laser sources configured to generate pump light.

[0059] In the illustrated example, the first group of laser sources 520-1 corresponding to the first input system may include one or more laser sources configured to provide signal light and / or one or more laser sources configured to provide first pump light, wherein the signal light and the first pump light are provided to a first combiner 200-1 (e.g., having a stray light stripper 250, as described herein) disposed between the first input system and an output optical fiber in an end-pumped or forward-pumped configuration. For example, as described herein, the output optical fiber may include one or more cores configured to carry signal light, and a cladding surrounding the core configured to carry pump light. The output optical fiber may be optically coupled to the fiber oscillator 510. Thus, the combiner 200-1 may combine the signal light and the pump light provided by the first group of laser sources 520-1 to form a first combined light (e.g., in a manner similar to that described elsewhere herein). In some implementations, the first combiner 200-1 may be configured as a pump combiner.

[0060] In some implementations, the first combiner 200-1 can provide the first combined light to the fiber oscillator 510, which can provide the first combined light to the second combiner 200-2 (e.g., having a stray light stripper 250, as described herein). Figure 5 As shown, a second group of laser sources 520-2 corresponding to a second input system can be configured to provide a second pump light to a second combiner 200-2 arranged between the second input system and the output fiber in a cascade pumping configuration. The output fiber can be optically coupled to a fiber amplifier 515. Therefore, the second combiner 200-2 can combine the first combined light and the second pump light to form a second combined light. The second combiner 200-2 can provide the second combined light to a fiber amplifier 515 (e.g., to one or more fiber amplifiers 515), which can amplify the second combined light and provide the second combined light to a third combiner 200-3 (e.g., which has a stray light stripper 250, as described herein).

[0061] For example, Figure 5 As shown, a third group of laser sources 520-3 corresponding to a third input system can be configured to provide a third pump light (e.g., which propagates in a direction opposite to the propagation direction of the second combined light) to a third combiner 200-3 arranged between the third input system and an output optical fiber in an anti-pump or reverse pump configuration. The output optical fiber can be optically coupled to the optical fiber amplifier 515. Therefore, the third combiner 200-3 can combine the second combined light and the third pump light to form a third combined light, and provide the third combined light to a laser output 525 (e.g., which can emit the third combined light toward a target of the optical system 500).

[0062] As mentioned above, Figure 5are provided as examples. Other examples can be found in the Figure 5 Different from what is described.

[0063] Figure 6 is a flow chart of an example process 600 associated with manufacturing a combiner. In some implementations, Figure 6 One or more process blocks of are performed by a manufacturing system. In some implementations, Figure 6 One or more process blocks of the manufacturing system are performed by another device or a group of devices that are separate from or include the manufacturing system (e.g., another system or subsystem configured to prepare a stray light stripper, prepare an optical fiber bundle, prepare a tapered capillary, etc.).

[0064] like Figure 6 As shown, process 600 may include forming a stray light stripper on a glass tube (block 610). In some implementations, forming the stray light stripper may include etching a surface of the glass tube using a chemical etching process. Additionally or alternatively, forming the stray light stripper may include using laser ablation to form grooves or notches in the surface of the glass tube.

[0065] like Figure 6 As further shown, process 600 may include inserting a fiber bundle into a glass tube, wherein the fiber bundle includes a plurality of optical fibers (block 620). The optical fibers may include one or more signal fibers and / or one or more pump fibers.

[0066] like Figure 6 As further shown, process 600 may include tapering a portion of the glass tube and a portion of the optical fiber bundle disposed within the glass tube (block 630). Figure 6 As further shown, process 600 may include cutting the optical fiber bundle (block 640). Figure 6 As further shown, process 600 may include splicing the fiber bundle to an output optical fiber (block 650).

[0067] although Figure 6 An example block diagram of process 600 is shown, but in some implementations, Figure 6 Process 600 includes more blocks, fewer blocks, different blocks, or differently arranged blocks than shown. Additionally or alternatively, two or more blocks of process 600 may be performed in parallel.

[0068] The above disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementation to the precise form disclosed. Modifications and variations may be made based on the above disclosure, or may be obtained from the practice of the implementation. In addition, any implementation described herein may be combined, unless the above disclosure explicitly provides reasons why one or more implementations cannot be combined.

[0069] Although specific combinations of features are cited in the claims and / or disclosed in the specification, these combinations are not intended to limit the disclosure of various implementations. In fact, many of these features can be combined in a manner that is not specifically cited in the claims and / or not disclosed in the specification. Although each dependent claim listed below can only directly depend on one claim, the disclosure of various implementations includes the combination of each dependent claim with each other claim in the claim set. As used herein, the phrase "at least one" referring to a list of items refers to any combination of these items, including single members. For example, "at least one of a, b or c" is intended to cover a, b, c, ab, ac, bc and abc, and multiple combinations of the same items.

[0070] Unless explicitly stated, any element, behavior or indication used in this article should not be interpreted as critical or essential. In addition, as used in this article, the articles "one" and "an" are intended to include one or more items, and can be used interchangeably with "one or more". In addition, as used in the text, the article "said" is intended to include one or more items related to the article "said", and can be used interchangeably with "one or more". In addition, as used in this article, the word "set" is intended to include one or more items (for example, a combination of related items, unrelated items, or related and unrelated items), and can be used interchangeably with "one or more". If only one item is intended to be used, the phrase "only one" or similar language is used. In addition, as used in this article, the terms "have", "have", "contain" etc. are intended to become open terms. In addition, unless otherwise explicitly stated, the word "based on" is intended to mean "at least partially based on". In addition, as used in this article, the term "or" is intended to be inclusive when used in series, and can be used interchangeably with "and / or", unless otherwise explicitly stated (for example, if used in combination with "any one of ..." or "only one of ...").

Claims

1. An optical system, comprising: Fiber oscillator or fiber amplifier; An input system comprising a plurality of laser sources, wherein the plurality of laser sources comprises at least one of the following: One or more first laser sources configured to generate a signal light, or one or more second laser sources configured to generate pump light; an output optical fiber, optically coupled to the fiber oscillator or the fiber amplifier, comprising a cladding and one or more cores, the one or more cores being configured to carry the signal light, the cladding surrounding the one or more cores being configured to carry the pump light; as well as A fiber combiner, arranged between the input system and the output fiber, comprising: a glass tube, wherein a stray light stripper is defined at a surface of the glass tube; as well as The optical fiber bundle is arranged in the glass tube and includes a plurality of optical fibers.

2. The optical system according to claim 1, wherein the optical system comprises the fiber oscillator and the fiber amplifier, wherein the fiber combiner is a first fiber combiner, the first fiber combiner is optically coupled to the fiber oscillator, and The optical system further comprises a second fiber combiner optically coupled to the fiber amplifier. 3 . The optical system according to claim 1 , wherein the plurality of laser sources include at least one of the first laser sources configured to generate signal light and at least one of the second laser sources configured to generate pump light. 4 . The optical system of claim 1 , wherein the plurality of laser sources includes a plurality of the second laser sources configured to generate pump light. 5 . The optical system of claim 1 , wherein the plurality of laser sources include a plurality of the first laser sources configured to generate signal light.

6. The optical system of claim 1, wherein the stray light stripper is defined by a chemical etch in the surface of the glass tube or a groove in the surface of the glass tube. 7 . The optical system of claim 1 , wherein the stray light stripper is configured to strip the stray light in the glass tube without stripping the pump light in the glass tube.

8. The optical system of claim 1, wherein the fiber combiner is arranged between the input system and the output fiber in a counter-pumping configuration.

9. An optical fiber combiner, comprising: Glass tube, wherein a stray light stripper is defined at a surface of the glass tube, wherein the stray light stripper is defined by a disturbance in the surface of the glass tube, or a layer of material on the glass tube having a refractive index different from that of the glass tube, and wherein the perturbation is a groove, notch or etching; as well as The optical fiber bundle is arranged in the glass tube and includes a plurality of optical fibers.

10. The fiber combiner of claim 9, wherein the plurality of optical fibers comprises one or more signal optical fibers and one or more pump optical fibers.

11. The fiber combiner of claim 9, wherein the plurality of optical fibers comprises a plurality of pump fibers.

12. The fiber combiner of claim 9, wherein the plurality of optical fibers comprises a plurality of signal optical fibers.

13. The fiber combiner of claim 9, wherein the perturbation is a chemical etch.

14. The fiber combiner of claim 9, wherein the perturbations are grooves in a sawtooth pattern.

15. The fiber combiner of claim 9, wherein the stray light stripper is defined at a non-tapered portion of the glass tube.

16. The optical fiber combiner of claim 9, wherein the stray light stripper is defined at a non-tapered portion of the glass tube and a tapered portion of the glass tube.

17. The fiber combiner of claim 9, wherein the perturbation comprises: A first row of grooves in a zigzag pattern centered at a 0° position relative to the circumference of the glass tube; a second row of grooves in a zigzag pattern centered at a 90° position relative to the circumference of the glass tube; a third row of grooves in a zigzag pattern centered at a position 180° relative to the circumference of the glass tube; as well as The fourth row of grooves has a zigzag pattern centered at a position of 270° relative to the circumference of the glass tube.

18. A method comprising: forming a stray light stripper on the glass tube; inserting an optical fiber bundle into the glass tube, wherein the optical fiber bundle includes a plurality of optical fibers; tapering a portion of the glass tube and a portion of the optical fiber bundle disposed within the glass tube; cutting the optical fiber bundle; as well as The fiber bundle is spliced ​​to an output optical fiber.

19. The method of claim 18, wherein forming the stray light stripper comprises: The surface of the glass tube is etched using a chemical etching process.

20. The method of claim 18, wherein forming the stray light stripper comprises: Laser ablation is used to form grooves or indentations in the surface of the glass tube.

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