WO2025019141A2

WO2025019141A2 - Optical fiber modules for additive manufacturing systems

Info

Publication number: WO2025019141A2
Application number: PCT/US2024/035942
Authority: WO
Inventors: Stephen C. COUITT; Scott Edwin BRACKETT; Troy Michael RZEZNIKIEWICZ; Jonathan Robert SILVA; Mark Christopher MORDARSKI; Eli OLIDORT; Christopher Anthony CONSOLI; Piotr LIEBERSBACH
Original assignee: Vulcanforms Inc.
Priority date: 2023-07-14
Filing date: 2024-06-28
Publication date: 2025-01-23
Also published as: WO2025019141A3

Abstract

Systems and methods for additive manufacturing are generally described. In some embodiments, an additive manufacturing system may include at least one mechanical fixture in the form of a resilient member for accurately biasing one or more optical fibers into alignment features (e.g., grooves formed in a fiber holder) to maintain a desired position and/or orientation of the fiber without the use of adhesives. In some embodiments, the additive manufacturing system may include magnetic elements configured to facilitate precise and accurate assembly of one or more housing elements without significant manual alignment. In some embodiments, the additive manufacturing system may include an active cooling system including channels to direct cooling fluid through the system to absorb thermal energy and reduce the risk of localized hot spots. The cooling system may direct cooling fluid flow in one or more directions along the axial dimension of the one or more optical fibers.

Description

OPTICAL FIBER MODULES FOR ADDITIVE MANUFACTURING SYSTEMS

RELATED APPLICATIONS

[0001] This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/513,615, filed July 14, 2023, the content of which is incorporated by reference in its entirety for all purposes.

FIELD

[0002] Disclosed embodiments are generally related to additive manufacturing systems and methods. More specifically, systems and methods employing the use of cooling systems for thermal regulation of optical elements and alignment systems for housing assembly systems are described.

BACKGROUND

[0003] The manufacturing speed and throughput of some additive manufacturing systems such as powder bed fusion systems is limited by the rate at which the powdered material can be fused. The rate of material fusion is dependent on multiple factors, including the total power delivered to the powdered material in the build volume of the system, as well as the energy per unit mass used to fuse the powdered material. In some instances, such as in systems utilizing one or more laser energy sources to deliver power to the build volume, the rate of fusion may be increased by including a plurality of laser energy sources. For example, by increasing the number of laser energy sources that can simultaneously fuse powder in a powder bed fusion process, the total power delivered to the build volume may be increased, and thus the rate of fusion can be increased.

SUMMARY

[0004] In some embodiments, additive manufacturing systems are disclosed. An additive manufacturing system may include at least one laser energy source, an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface, at least one optical fiber optically coupling the at least one laser energy source with the optics assembly, a fiber holder configured to support at least a portion of the at least one optical fiber. The holder may include a first portion comprising a non-magnetic material, a second portion comprising a magnetic material, and at least one groove formed in and extending along at least partially across the first portion and the second portion of the holder, wherein the at least one optical fiber is disposed in the at least one groove.

[0005] In some embodiments, additive manufacturing systems are disclosed. An additive manufacturing system may include a first portion comprising a non-magnetic material, a second portion comprising a magnetic material, at least one groove formed in and extending along at least partially across the first portion and the second portion of the holder, wherein the at least one groove is configured to support at least a portion of at least one optical fiber.

[0006] In some embodiments, additive manufacturing systems are disclosed. An additive manufacturing system may include at least one laser energy source, an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface, at least one optical fiber optically coupling the at least one laser energy source with the optics assembly, a fiber holder configured to support at least a portion of the at least one optical fiber. The fiber holder may include at least one channel configured to direct a flow of cooling fluid through the fiber holder, wherein a first portion of the at least one channel is configured to direct the flow of cooling fluid in a first direction that is at least partially parallel to an axial dimension of the at least one optical fiber, and wherein a second portion of the at least one channel is configured to direct flow of cooling fluid in a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber and at least partially opposite the first direction.

[0007] In other embodiments, methods for additive manufacturing are disclosed. A method for additive manufacturing may include transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber, flowing cooling fluid through a first portion of at least one channel formed in a fiber holder along a first direction that is at least partially parallel to the axial dimension of the at least one optical fiber, and flowing the cooling fluid through a second portion of the at least one channel formed in the fiber holder along a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber, wherein the second direction is at least partially opposite the first direction.

[0008] In other embodiments still, additive manufacturing systems are disclosed. An additive manufacturing system may include at least one laser energy source, an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface, at least one optical fiber optically coupling the at least one laser energy source with the optics assembly, and a fiber holder including a first portion and a second portion, wherein the at least one optical fiber is disposed between the first portion and the second portion of the fiber holder, at least one channel configured to direct a flow of cooling fluid through the fiber holder, wherein the at least one channel includes a first portion of the at least one channel disposed in the first portion of the fiber holder and a second portion of the at least one channel disposed in the second portion of the fiber holder, and wherein a portion of the at least one optical fiber is disposed between the first portion of the at least one channel and the second portion of the at least one channel.

[0009] In other embodiments still, additive manufacturing systems are disclosed. An additive manufacturing system may include at least one laser energy source, an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface, at least one optical fiber optically coupling the at least one laser energy source with the optics assembly, and a fiber holder, wherein the fiber holder supports a portion of the at least one optical fiber, a first manifold disposed on a first surface of the fiber holder, a first lid disposed on the first manifold, wherein the first manifold is disposed between the first lid and the fiber holder, and at least one channel having a first portion formed between the first manifold and the fiber holder and a second portion formed between the first manifold and the first lid.

[0010] In other embodiments still, methods for additive manufacturing are disclosed. A method for additive manufacturing may include transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber, flowing cooling fluid through at least one channel of a fiber holder, wherein the fiber holder supports a portion of the at least one optical fiber, the at least one channel formed between the fiber holder and a first manifold of a cooling system, and flowing the cooling fluid along at least one channel formed between the first manifold and a first lid, the first lid configured to be coupled to the fiber holder.

[0011] In other embodiments still, additive manufacturing systems are disclosed. An additive manufacturing system may include at least one laser energy source, an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface, at least one optical fiber optically coupling the at least one laser energy source with the optics assembly, a holder configured to support at least a portion of the at least one optical fiber, and a cylindrical resilient member configured to bias at least the portion of the at least one optical fiber towards the holder, the cylindrical resilient member having a flat tip oriented towards and in contact with the at least one optical fiber.

[0012] In other embodiments still, methods for additive manufacturing are disclosed. A method for additive manufacturing may include transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber, and biasing at least a portion of the at least one optical fiber towards a holder with a cylindrical resilient member, the holder configured to support the at least a portion of the at least one optical fiber, the cylindrical resilient member having a flat tip oriented towards and in contact with the at least one optical fiber.

[0013] It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various nonlimiting embodiments when considered in conjunction with the accompanying figures.

[0014] Other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments of the disclosure when considered in conjunction with the accompanying figures.

BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings:

[0016] FIG. 1 shows, according to some embodiments, a schematic of a portion of a fiber optic assembly of an additive manufacturing system;

[0017] FIG. 2 shows, according to some embodiments, an additive manufacturing system;

[0018] FIG. 3 shows, according to other embodiments, an additive manufacturing system;

[0019] FIGs. 4A-4B show, according to other embodiments still, orthographic views of additive manufacturing systems;

[0020] FIG. 5 shows a partial exploded orthographic view of an additive manufacturing system from FIG. 4A;

[0021] FIG. 6 shows a close-up from FIG. 5 along detail 6;

[0022] FIGs. 7A-7D show, according to some embodiments, a process of manufacturing an alignment fixture;

[0023] FIGs. 8A-8B shows an orthographic close-up view of the alignment fixtures of FIG. 7DD;

[0024] FIGs. 9A-9C show perspective views of an upper housing according to some embodiments;

[0025] FIGs. 10A-10C show, according to some embodiments, exploded orthographic views of a housing of an additive manufacturing system;

[0026] FIG. 11 shows, according to some embodiments, a housing of an additive manufacturing system;

[0027] FIG. 12 shows, according to some embodiments, a cross-sectional view of an additive manufacturing system taken along line 12-12 in FIG. 4A;

[0028] FIGs. 13A-13B show, according to some embodiments, orthographic views of active cooling systems;

[0029] FIG. 14 shows, according to other embodiments, an orthographic view of an active cooling systems; [0030] FIG. 15 shows, according to some embodiments, a front view of an alignment features of a fiber optic assembly;

[0031] FIGs. 16A-16G show, according to some embodiments, optical fibers including endcaps; and

[0032] FIGs. 17A-17C show, according to some embodiments, top views of transmission of laser energy through endcaps coupled to optical fibers.

DETAILED DESCRIPTION

[0033] The Inventors have appreciated that additive manufacturing systems utilizing multiple optical fibers, which may be arranged in an array format, to deliver laser energy from one or more laser energy sources to powder in a build volume can present various challenges. For example, it may be difficult to accurately align the optical fibers relative to downstream optics (e.g., lenses, lens arrays, mirrors, etc.) for precise energy delivery. In some instances, additive manufacturing systems can use adhesives (e.g., epoxy resins) to fix or align a portion of the optical fibers relative to the relevant optical components.

[0034] The Inventors have recognized that in some cases, the use of adhesives alone may be insufficient to maintain a desired alignment and position of the optical fibers within the system. Given the precise tolerances required for operation of additive manufacturing systems, as well as the large scales over which such systems may operate, the Inventors have recognized that adhesives may not deliver the level of precision and longevity desired for such systems. For example, adhesives may be affected by the heat generated by delivering large powers to a build surface through the optical fibers. Thus, the Inventors have recognized a need for a supplementary component in addition to adhesives to help orient the optical fibers within the system and retain their orientation over time and during operation. [0035] In view of the above, the Inventors have recognized and appreciated the numerous benefits associated with an additive manufacturing system employing mechanical fixtures for retaining a desired position of optical fibers relative to other optical components in the system. The mechanical fixtures may serve to maintain a position of the optical fibers even when localized heating of the optical fibers and/or associated components occurs during operation, for example due to scattering, back reflection, and/or other optical effects. The Inventors have also recognized the benefits associated with mechanical fixtures which can accommodate variations in optical fiber sizes within an array, such that each optical fiber in the array is retained or otherwise fixed in the same manner.

[0036] Furthermore, the Inventors have recognized the benefits associated with a mechanical fixture system which helps retain an optical fiber, which may have a circular cross-section, within a groove formed in a fiber holder. In some cases, the optical fibers may be arranged in the groove of the holder, but not properly seated within said groove. Such misalignment of the fiber within the groove may also result in misalignment between neighboring optical fibers, which may reduce the precision and accuracy of the additive manufacturing system. Thus, the Inventors have recognized the benefits associated with a mechanical fixture that helps retain the cylindrical fibers in place regardless of their initial position within the groove.

[0037] The use of mechanical fixtures offers several benefits, including, for example, improved registration of the optical fibers with a desired position with the system.

Additionally, in some cases, the mechanical fixtures may be configured to cool or otherwise direct heat (e.g., heating from laser energy leakage) away from the optical fiber. Of course, while several potential benefits are listed above, it should be understood that embodiments in which not all of the listed benefits and/or different benefits are provided by a mechanical fixture are also contemplated as the disclosure is not limited to only the listed benefits.

[0038] In some embodiments, an additive manufacturing system may employ one or more mechanical fixtures in the form of one or more resilient members to bias or otherwise retain one or more optical fibers in a desired position relative to one or more downstream components of an optics system which serves to direct laser energy from one or more laser energy sources to a build surface of an additive manufacturing system. The one or more resilient members may apply a force either directly, or indirectly, to one or more optical fibers that is directed towards an underlying supporting portion of the mechanical fixture located opposite from the one or more resilient members.

[0039] In some embodiments, the resilient members may be formed with a substantially flat distal surface with which they may bias against the side of an optical fiber, urging the fiber into a support surface (e.g., a groove). The flat distal surface of the resilient member may help seat the optical fibers, which may be cylindrical, properly in the support structure, regardless of the initial position of the optical fibers relative to the groove. For example, if the optical fiber is initially arranged at a non-central position in the groove, the large surface area of a flat-tipped fixture may help urge the resilient member into the groove. A resilient member with a flat distal surface may therefore have an increased surface area for contacting and urging the optical fiber into the groove relative to a resilient member with a smaller distal surface area (e.g., a spheric al-tipped resilient member). Thus, a resilient member with a flat distal surface may increase the likelihood of the fibers being properly seated within the support structures (e.g., grooves), improving the overall performance of the additive manufacturing system.

[0040] In some embodiments, the supporting portion of the mechanical fixture may be an alignment fixture (e.g., a groove formed in a fiber holder) configured to keep at least a portion of the fibers aligned and oriented in a desired direction and position within the alignment fixture. This may facilitate coupling of the alignment fixture and the associated optical fibers with the overall optics assembly of the system including optical components such as lenses, optics stacks, and/or other optical components located downstream from the one or more optical fibers. In some embodiments, the mechanical fixture may include a clamp which serves to prevent or reduce transverse (e.g., perpendicular to the longitudinal axis of the fibers) movement of at least a portion of the optical fibers. In some embodiments, the mechanical fixtures may be configured to retain or otherwise fix a portion of the optical fibers without the use of adhesives. Specific constructions and features of resilient members are described in greater detail with reference to the figures below.

[0041] In some embodiments, the one or more mechanical fixture(s) of the additive manufacturing systems described herein may be associated with one or more alignment fixtures to help orient, align, and/or transversely fix a portion of the optical fibers. For example, the one or more mechanical fixtures may bias the optical fibers against an alignment fixture formed of grooves to help retain the fibers in alignment. Of course, the mechanical fixtures described herein may also retain the optical fibers against a flat surface and/or any other suitable alignment fixture, as the present disclosure is not so limited.

[0042] In some embodiments, one or more portions of a mechanical fixture (e.g., a plurality of spring-loaded pistons forming a resilient member, as will be described with respect to the figures below) may be formed of a mechanically compliant material. The mechanical fixture may be formed of any suitable material which may robustly retain the optical fibers in place without applying excessive stress to the optical components, thereby distorting the optical signal. One or more portions of the mechanical fixture may be formed of a flexible and/or compliant material, such as one or more metals. In some embodiments, one or more structural features (e.g., spring-loaded pistons) may provide the desired biasing force to the optical fibers. It should be appreciated that the materials used to construct the mechanical fixture may be machinable and/or compatible with relevant manufacturing techniques. It should be appreciated that any suitable material or combinations of materials (e.g., composites, laminates) may be employed for any portion of the mechanical fixtures described herein.

[0043] In some embodiments, the mechanical fixture may be formed as part of housing elements of the additive manufacturing system, which serve to retain the various components in place. The Inventors have recognized and appreciated the numerous benefits associated with an additive manufacturing system employing magnetic retention systems to facilitate the alignment between the housing elements. In some embodiments, the use of a magnetic retention system may facilitate the alignment and orientation of the optical fibers in a rapid and precise manner without significant manual alignment. In some embodiments, a magnetic retention system may help retain the optical fibers in place during assembly and fabrication, without applying a significant load to the fibers. In some embodiments, the magnetic retention system may include magnetic elements arranged in a housing body, which may magnetically interact with a metallic clamp positioned the optical fibers, in either a permanent or temporary manner. In some embodiments, the arrangement of the clamp on the fibers may help temporarily (or permanently) orient and align the fibers. For example, the arrangement of a clamp on the fibers may urge the fibers into an alignment fixture (e.g., grooves) in a housing element. The clamp may apply a biasing force through its magnetic interaction with the housing element. The biasing force may be high enough to urge the fibers in position into grooves, but low enough to reduce the risk of damaging or warping the optical fibers.

[0044] In some embodiments, the magnetic retention systems may magnetically bias a first housing element toward a second housing element. The magnetic biasing system may allow the housing elements to be aligned in a pre-determined arrangement, eliminating the need for high-tolerance alignment between the two elements. In other words, the magnetic attraction between the housing elements may induce precise alignment between the two (or more) elements without significant manual alignment. In some embodiments, this rapid and precise alignment process may expedite the assembly process of an additive manufacturing system.

[0045] In some embodiments, a magnetic retention system may be formed as part of a housing element. For example, a housing element may include a cavity, within which a metallic or otherwise non-magnetic body may be arranged. The metallic body may be potted or otherwise fixed in the cavity of the housing element to reduce the risk of the body moving relative to the housing due to magnetic forces. The attachment of the metallic body to the housing element may allow any further processing to be applied uniformly to both the metallic body and the housing element. For example, a series of alignment fixtures (e.g., grooves) may be formed in both of the housing element and metallic body together, such that the interface between the metallic body and the housing element may be indiscernible, allowing for more precise alignment. As will be described in greater detail below, the metallic body arranged in one housing element may interact with magnetic bodies in another housing element. In some embodiments, the magnetic bodies may be temporarily arranged in the other housing element to facilitate housing assembly, and may be subsequently removed from the system. In other embodiments, the magnetic bodies may be permanently arranged in the other housing element. The magnetic bodies may be formed at least partially of a paramagnetic and/or ferromagnetic material.

[0046] Furthermore, in view of the heat generation discussed above, the Inventors have recognized and appreciated the numerous benefits associated with an active cooling system for continually transporting heat away from the optical fibers to maintain the fibers, and the nearby components of the system, at operating temperatures. The active cooling system counteract localized heat generation associated with transmission of high power laser energy to keep the optical fibers at a functional temperature, reduce the risk of optical beam distortion as a result of heating (e.g., physical warping of the fiber and/or surrounding optical components), and prolong the lifetime of the fibers.

[0047] Thus, in some embodiments, an additive manufacturing system may include a forced fluid active cooling system for helping transport thermal energy away from the optical fibers. The active cooling system may flow fluid (e.g., water) through channels formed in one or more portions of the additive manufacturing system. Due to the fluid’s thermal conductivity, the fluid may absorb the local heat generated in the additive manufacturing system and transport said heat to an outlet. The channels may be arranged proximal to the optical fibers, without directly contacting the cooling fluid with the optical fibers. The fluid may be continually flown through the channels of the system to continuously transport thermal energy away from the additive manufacturing system. As will be described in greater detail below, the cooling system may employ structural features to ensure uniform thermal transport away from the optical fibers. In some embodiments, cooling fluid may flow generally aligned with the axial dimension of the optical fibers, whereas in other embodiments, cooling fluid may flow across the axial dimension of the optical fibers.

[0048] The cooling fluid used in the thermal systems described herein may be any suitable fluid capable of absorbing thermal energy from the system and transporting said thermal energy away from the system in a reasonable timeframe to allow for continuous cooling. The cooling fluid may include water, dielectric fluids, mineral oils, hydrocarbons, organic fluids, combinations thereof, and/or any other suitable fluid or combinations of fluids. It should be appreciated that the cooling fluid employed may be compatible with the materials of the system, such as rubber sealing gaskets, metallic housing components, and others. In some embodiments, an additive manufacturing system may be in thermal communication with, or include integrated, heat exchangers such as heat sinks for passive thermal management, or active cooling systems such as thermoelectric coolers, in addition to the active forced fluid system described above. The heat exchanger may include large surface areas (e.g., via fins) to maximize convection of heat away from the various components of the system to cool the optical fibers. It should be appreciated that any active or passive cooling systems, including combinations of both, may be employed to cool the optical fibers, as the present disclosure is not so limited.

[0049] As will be described in greater detail below, an additive manufacturing system may employ an active cooling system which may direct cooling fluid proximal to the optical fibers. In some embodiments, the active cooling system may include channels oriented at least partially across the longitudinal dimension of the optical fibers. In such systems, the cooling fluid may flow across a series of optical fibers, absorbing thermal energy as it flows. Although such systems may have simple and easy to manufacture designs, the Inventors have recognized that fluid in such a system may have a reduction of its capacity to absorb thermal energy as it passes through the channels. Accordingly, the fluid may not absorb the same amount of heat from all optical fibers equally. Furthermore, the Inventors have recognized that absorbing thermal energy across the optical fibers may induce a thermal gradient along a tangential dimension of the fibers (e.g., between a cooling fluid outlet arranged on one side of the fibers to a cooling fluid outlet arranged on the opposing side of the fibers. Such a thermal gradient may result in localized expansion and/or undesirable warpage, due to potential heating and thermal expansion of nearby elements.

[0050] Thus, in some embodiments, an additive manufacturing system may employ an active cooling system with channels oriented approximately along the longitudinal dimension of the optical fibers. Such channels may allow cooling fluid to travel along the direction of the optical fibers and absorb thermal energy along the optical fibers. In this way, the cooling system may reduce the likelihood of a significant thermal gradient along the optical fibers tangential dimension. In some embodiments, the channels may allow fluid to flow in a proximal direction along the longitudinal dimension of the optical fibers, as well as in a distal direction along the longitudinal dimension. In this way, the fluid may pass along a greater interfacial distance between the channel and the optical fibers, to enhance the absorption of thermal energy from the fibers.

[0051] As will be described in greater detail below, in some embodiments, the cooling system may be at least partially integrating into housing elements. The channels may be formed between cavities of the housing and other adjacent elements, such as a channel manifold. In embodiments where the cooling system includes channels that facilitate cooling fluid flow in two directions relative to the optical fiber longitudinal dimension, the cooling system may include a first set of channels formed between a lid and a first face of a manifold, which may be fluidically coupled to a second set of channels formed between a second face of the manifold, and a housing element. It should be appreciated that the active cooling systems described herein may include channels formed in a first housing element (e.g., upper housing portion) as well as channels formed in a second housing element (e.g., lower housing portion). Accordingly, the cooling fluid may help transport thermal energy away from two sides of the optical fibers for more efficient cooling. [0052] In some embodiments, an additive manufacturing system may employ the use of a stray light baffle configured to redirect stray (e.g., scattered, reflected, back scattered, back reflected, refracted, diffuse, etc.) light or laser energy that is propagating toward one or more optically coupled laser energy sources. The stray light baffle may be in optical communication, and in some instances in direct contact, with the one or more optical fibers optically coupled with the laser energy source. In this way, the stray light baffle may be shaped and constructed to reduce the amount of light directed back towards the energy source. The stray light baffle may also reduce the amount of stray light directed away from the laser source, which may locally heat the optical fibers in an undesirable fashion. In some cases, the stray light baffle may also serve to cool or otherwise direct heat (e.g., laser energy) away from the one or more optical fibers. In some instances, the stray light baffle may redirect thermal energy to cooling systems or regions of the additive manufacturing system with enhanced thermal management capabilities. Of course, while several potential benefits are listed above, it should be understood that embodiments in which not all of the listed benefits and/or different benefits are provided by an optical element are also contemplated as the disclosure is not limited to only the listed benefits.

[0053] As noted above, in some embodiments, an additive manufacturing system may employ one or more stray light baffles to deflect or otherwise redirect (e.g., scatter) at least a portion of stray light transmitted through the one or more optical fibers. In the absence of the stray light baffle, at least a portion of the stray light may be directed toward the one or more laser energy sources or other components, which can damage the laser energy source, optical fibers, and/or other components in the surrounding environment. The stray light baffle(s) may be optically connected to the optical fibers, such that stray light may pass from the fibers to the baffle to be redirected out of the main optical pathway between the laser energy source and the build volume through the fibers. For example, in some embodiments, the baffle may include one or more alignment fixtures which can hold (e.g., align or orient) the optical fibers. In this way, the baffle may serve to both align the optical fibers and direct light away from them. Specific constructions and features of stray light baffles are described in greater detail with reference to the figures below.

[0054] Accordingly, in some embodiments, optical fibers may transmit laser energy from one or more laser energy sources, through one or more optical components directed to a build surface. The optical fibers may be both physically supported by and/or optically coupled to the one or more optical components. For example, in additive manufacturing embodiments which include one or more stray light baffles, the stray light baffles may serve to physical orient, position, and/or align a portion of the optical fibers, as well as optically redirecting or deflecting stray light from the fibers (e.g., backscattered light traveling toward the laser energy source). As will be described in greater detail below, the stray light baffles may physically retain a portion of the optical fibers with one or more alignment fixtures (e.g., grooves).

[0055] In some embodiments, an additive manufacturing system may include a laser energy source (e.g., a plurality of laser energy sources) and an optics assembly configured to direct laser energy from the laser energy source (e.g., the plurality of laser energy sources) onto a build surface. According to some embodiments, one or more optical fibers may be coupled directly or indirectly to the one or more laser energy sources. In some embodiments, an additive manufacturing system may include one or more endcaps that are optically and physically coupled to the distal ends of one or more associated optical fibers used to provide laser energy to the additive manufacturing system. The endcaps may reduce a power area density of transmitted laser energy prior to transmission through a distal surface of the endcaps by providing an increased transmission area of the laser energy relative to a transverse cross-sectional area of the optical fibers without an endcap. The laser energy output from the endcap or endcaps may be directed onto a build surface through one or more intervening optical components of the optics assembly to form a laser energy spot on the build surface (e.g. lenses, optical fibers, galvo-scanners, lens arrays, etc.). Exposure of the laser energy to powdered material on the build surface may be used to fuse at least a portion of the powder to form a desired geometry on the build surface. In some instances, the optics assembly may be configured to form an array of laser energy spots on the build surface from the laser energy from each laser energy source. For example, the optics assembly may be configured to direct laser energy from each laser energy source to form one or more corresponding laser energy spots in the array. The array of laser spots may be a linear array, according to certain embodiments. However, the array of laser spots may be a two- dimensional array, according to certain embodiments. Additionally, additive manufacturing systems in which only a single laser energy spot is used are also contemplated as the disclosure is not limited in this fashion.

[0056] As noted above, it may be desirable to accurately locate and position one or more portions of the optical fibers and/or endcaps within a system for accurate delivery of laser energy to a build volume. Accordingly, in some embodiments, an additive manufacturing system may employ one or more alignment fixtures which may receive one or more optical fibers and/or endcaps coupled with the optical fibers. For example, the alignment fixture may define a desired spatial distribution and/or orientation of one or more portions of the optical fibers. In one such embodiment, the alignment fixture may orient each optical fiber and/or endcap to be oriented in parallel directions such that light traveling through the optical fibers and/or endcaps may exit the alignment fixture along one or more paths that are parallel to a desired transmission direction. The alignment fixture may also facilitate accurately positioning the one or more optical fibers and/or endcaps at predetermined positions relative to a length, width, and/or thickness of the alignment fixture where the width and thickness directions may be perpendicular to a length of the alignment fixture which is parallel to the longitudinal axes of the portions of the optical fibers positioned therein. In certain embodiments, an alignment fixture may include a plurality of alignment features such as v-grooves, holes, optical wedges, optical blocks, and/or any other appropriate alignment feature which the optical fibers and/or endcaps may be positioned in or engaged with to appropriately position the optical fibers and/or endcaps. Depending on the particular embodiment, the alignment features may be arranged in any suitable manner to define a desired spatial distribution (e.g., pitch) and absolute position(s) of the end portions of the optical fibers and/or endcaps held in the alignment fixture.

[0057] The alignment fixtures described herein may be made from any appropriate material or combination of materials including, for example, metals such as copper, nickeliron alloys such as Invar, ceramics such as glass, sapphire, and diamond, and/or any other appropriate material capable of supporting the optical fibers thereon. Additionally, in some embodiments, laminates of these materials may be used. For instance, a ceramic layer may be disposed on a thicker and more thermally conductive metal layer. In either case, the overall materials and construction may be selected to provide a desired thermal conductivity and/or thermal expansion as detailed further below in some embodiments. In some embodiments, the various components herein may include surface coatings with desired optical properties, including, but not limited to, gold or silver.

[0058] The additive manufacturing systems described herein may employ one or more optical fiber connectors coupled to either one, or a plurality of, laser energy sources (e.g., of the plurality of laser energy sources and the optics assembly). For example, a first optical fiber or first plurality of optical fibers may be optically coupled to the one or more corresponding laser energy sources and extend to and be connected with the optical fiber connector. Additionally, a second optical fiber or second plurality of optical fibers may extend from the optical fiber connector to the optics assembly to which the second plurality of optical fibers may be optically coupled. An optical fiber connector may be configured such that the one or more second optical fibers may be optically coupled to a corresponding optical fiber of the one or more first optical fibers within the optical fiber connector. In this manner, laser energy from the laser energy source or plurality of laser energy sources may be transmitted via the first optical fiber or first plurality of optical fibers to the optical fiber connector, and subsequently to the optics assembly via the second optical fiber or second plurality of optical fibers such that the laser energy can be delivered to the build surface. Depending on the particular embodiment, an optical fiber connector may be connected to either a stationary or movable optics assembly. This may include, for example one, or both, of the above noted connections between the separate optical fibers and the optical fibers with the optics assembly. Thus, it should be understood that the use of the disclosed optical fibers is not limited to only the specific constructions and embodiments described herein.

[0059] In the various embodiments described herein, laser energy may be generated by one or more independently controllable laser energy sources and that are operated to deliver the laser energy to the optics assembly through one or more separate optical fibers associated with the laser energy sources. It should be understood that any appropriate type of optical fiber may be used including, for example, solid-core optical fibers. However, in other embodiments, the one or more optical fibers may include fiber segments spliced together to form a single optical fiber. Alternatively or additionally, a single optical fiber path may be generated by using an optical connector to couple the ends of two fibers together.

[0060] Regardless of the specific optical fiber construction, each optical fiber optically connected to the one or more laser energy sources of an additive manufacturing system may be appropriately routed to and optically connected with the optics assembly of the additive manufacturing system. In some embodiments, the distal ends of the one or more optical fibers may be disposed on and optically coupled to an endcap which is received in a mounting fixture (e.g., a fiber holder) that ensures the endcap of the optical fiber is properly aligned. For example, if the additive manufacturing system comprises a plurality of optical fibers, the distal end portions of the optical fibers may be oriented parallel to one another and the distal ends of the endcaps may be aligned with one another at a predetermined axial position within the mounting fixture, according to certain embodiments. This may facilitate coupling of the mounting fixture and the associated optical fibers with the optics assembly of the system. Specific constructions and features for aligning the endcaps of a system are described in greater detail with reference to the figures below.

[0061] As noted above, in some embodiments, an optical fiber extends between a laser energy source (and/or a plurality of laser energy sources) and an optics assembly of an additive manufacturing system. The optical fiber may be used, according to certain embodiments, to transmit laser energy from a laser energy source along an axial dimension of the optical fiber. The optical fiber may be directly connected to the laser energy source and/or the optics assembly. For example, according to some embodiments, the optical fiber is directly connected to both the optics assembly (e.g., at a distal end of the optical fiber) and to the laser energy source (e.g., at a proximal end of the optical fiber). In some embodiments, the optical fiber is only directly connected to either the optics assembly or the laser energy source. For example, according to certain embodiments, one end of the optical fiber is connected to an optical connector and a separate optical fiber is connected to the optics assembly. Further in some embodiments, an optical fiber is directly connected to neither the laser energy source nor the optics assembly. Regardless, the optical fibers disclosed herein may be incorporated at any appropriate location between the laser energy sources and the optics assembly.

[0062] Embodiments referring to an optical fiber may be interpreted as referring to a single optical fiber, or one of a plurality of optical fibers handled in a similar fashion, according to certain embodiments. Thus, references to one or more optical fibers, an optical fiber, a single optical fiber, or other similar terminology in the various embodiments described herein should be understood to apply to both single optical fibers as well as a plurality of optical fibers as the disclosure is not so limited. In some embodiments where a plurality of optical fibers is used, the plurality of optical fibers may be aligned with corresponding predetermined positions and orientations with one or more alignment fixtures, which may correspond with mechanical fixtures described previously, or may be standalone features. For example, the optical fibers may be aligned axially such that the distal ends of the endcaps associated with the plurality of optical fibers are positioned within a predetermined range (i.e. a tolerance) of a desired axial position within the system. The optical fibers may also be aligned in one or more transverse directions relative to the axial direction of the optical fibers. For example, the optical fibers may be aligned with one another relative to a width and/or thickness direction of the optical fibers within an array arrangement of the optical fibers. The optical fibers and endcaps may be aligned in a linear array, in some embodiments. According to other embodiments, the optical fibers and endcaps may be aligned in a two-dimensional array. The alignment of the optical fibers may, according to certain embodiments, result in an advantageous arrangement of laser energy pixels, and in a preferred positioning of endcaps of the plurality of optical fibers with respect to downstream optics.

[0063] In some embodiments, the incident laser spots on a build surface may be arranged in a line with a long dimension and a short dimension, or in an array. In either case, according to some aspects, a line, or array, of incident laser energy consists of multiple individual laser energy pixels arranged adjacent to each other that can have their respective power levels individually controlled. Each laser energy pixel may be turned on or turned off independently and the power of each pixel can be independently controlled. Due to the resulting pixel-based line or array being scanned primarily perpendicular to the long axis of the line or array in some embodiments, the forward velocities and pixel power densities may be bound by approximately the same power and velocity limits as traditional single spot laser selective melting processes. However, because there are multiple spots directly adjacent to each other, the effective process rate can be approximately N times the single pixel rate, where N is the number of available pixels. Also, because each pixel can be individually turned on or off, the effective part resolution and accuracy remains comparable to a single spot system. The system can be operated as a single spot system by only turning on a single pixel, or by relying on a single optical fiber extending between a single endcap and a single laser energy source, but then the effective system rate will be substantially the same as a single spot system.

[0064] Depending on the particular embodiment, an additive manufacturing system according to the current disclosure may include any suitable number of laser energy sources. For example, in some embodiments, the number of laser energy sources may be at least 5, at least 10, at least 50, at least 100, at least 500, at least 1,000, at least 1,500, or more. In some embodiments, the number of laser energy sources may be less than 2,000, less than 1,500, less than 1,000, less than 500, less than 100, less than 50, or less than 10. Additionally, combinations of the above-noted ranges may be suitable. Ranges both greater and less than those noted above are also contemplated as the disclosure is not so limited.

[0065] Additionally, in some embodiments, a power output of a laser energy source (e.g., a laser energy source of a plurality of laser energy sources) may be between about 50 W and about 2,000 W (2 kW). For example, the power output for each laser energy source may be between about 100 W and about 1.5 kW, and/or between about 500 W and about 1 kW.

Moreover, a total power output of the plurality of laser energy sources may be between about 500 W (0.5 kW) and about 4,000 kW. For example, the total power output may be between about 1 kW and about 2,000 kW, and/or between about 100 kW and about 1,000 kW.

Ranges both greater and less than those noted above are also contemplated as the disclosure is not so limited.

[0066] Depending on the embodiment, an array of laser energy pixels (e.g., a line array or a two dimensional array) may have a uniform power density along one or more axes of the array including, for example, along the length dimension (i.e. the longer dimension) of a line array. In other instances, an array can have a non-uniform power density along either of the axes of the array by setting different power output levels for each pixel’s associated laser energy source. Moreover, individual pixels on the exterior portions of the array can be selectively turned off or on to produce an array with a shorter length and/or width. In some embodiments, the power levels of the various pixels in an array of laser energy may be independently controlled throughout an additive manufacturing process.

[0067] Generally, laser energy produced by a laser energy source has a power area density. In some embodiments, the power area density of the laser energy transmitted through an optical fiber is greater than or equal to 0.02 W/micrometer², greater than or equal to 0.04 W/micrometer², greater than or equal to 0.08 W/micrometer², greater than or equal to 0.1 W/micrometer², greater than or equal to 0.5 W/micrometer², greater than or equal to 1 W/micrometer², or greater. In some embodiments, the power area density of the laser energy transmitted through the optical fiber is less than or equal to 1 W/micrometer², less than or equal to 0.5 W/micrometer², less than or equal to 0.1 W/micrometer², less than or equal to 0.08 W/micrometer², less than or equal to 0.04 W/micrometer², less than or equal to 0.02 W/micrometer², or less. Combinations of these ranges are possible. For example, in some embodiments, the power area density of the laser energy transmitted through the optical fiber is greater than or equal to 0.04 W/micrometer² and less than or equal to 0.1 W/micrometer². [0068] The power area density of the laser energy transferred from the distal end of an optical fiber into an associated endcap may be reduced, in some embodiments, by increasing a transmission area of the transmitted laser energy within an endcap. For example, according to certain embodiments, the power area density is reduced by a factor of greater than or equal to approximately 1, 5, 10, 20, 50, 100, 200, 250, , or more within the endcap relative to the power area density within the associated optical fiber. The reduction in power area density may also be less than or equal to a factor of approximately 250, 200, 100, 50, 20, 15, 10, or 5 times less than the power area density within the associated optical fiber. In view of the above, in certain embodiments, the transmission area of the transmitted laser energy, such as a distal surface area of the endcap oriented towards one or more downstream optics, may correspondingly be increased by a factor of at least 1.1, at least 1.2, at least 1.5, at least 2, at least 2.5, at least 3, at least 4, at least 5, at least 10, or at least 15, or more within the endcap relative to a transverse cross sectional area of the associated optical fiber (e.g. a transverse cross-sectional area of a core of the optical fiber). The transmission area of the transmitted laser energy within the endcap may also be less than or equal to 50, 20, 15, 10, or 5 times greater than the transmission area (e.g. transverse cross sectional area) of the associated optical fiber. Combinations of the foregoing ranges are contemplated including, for example, a reduction in power area density within an endcap optically coupled to an optical fiber may be between or equal to 50and 200 times less than or equal to the power area density within the optical fiber. Correspondingly, the transmission area within the endcap may be between or equal to 1.1 and 50 times greater than or equal to the transmission area of the associated optical fiber. Of course, ranges both greater than and less than those noted above are also contemplated as the disclosure is not so limited.

[0069] Depending on the application, output of the optics assembly may be scanned across a build surface of an additive manufacturing system in any appropriate fashion. For example, in one embodiment, one or more galvo scanners may be associated with one or more laser energy sources to scan the resulting one or more laser pixels across the build surface. Alternatively, in other embodiments, an optics assembly may include an optics head that is translated in a direction parallel to a plane of the build surface to scan the one or more laser pixels across the build surface. In either case, it should be understood that the disclosed systems and methods are not limited to any particular construction for scanning the laser energy across a build surface of the additive manufacturing system.

[0070] For the sake of clarity, transmission of laser energy through an optical fiber is described generically throughout. However, with respect to various parameters such as transverse cross-sectional area, transverse dimension, transmission area, power area density, and/or any other appropriate parameters related to a portion of an optical fiber that the laser energy is transmitted through, it should be understood that these parameters refer to either a parameter related to a bare optical fiber and/or a portion of an optical fiber that the laser energy is actively transmitted through such as an optical fiber core, or a secondary optical laser energy transmitting cladding surrounding the core. In contrast, any surrounding cladding, coatings, or other materials that do not actively transmit the laser energy may not be included in the disclosed ranges.

[0071] It should be appreciated that the additive manufacturing systems described herein may employ any suitable number, type, arrangement, and combination of laser energy sources, optical fibers, fiber bundles, optical elements (e.g., lenses, connectors, etc.), endcaps, baffles, mechanical fixture, alignment fixtures (e.g., holders), and/or any other elements. Therefore, the embodiments disclosed herein are not limited by the type, number, arrangement, or presence of one or more of the aforementioned features.

[0072] While the mechanical fixtures disclosed herein may be used to replace adhesives in certain portions of the optical system of an additive manufacturing, the use of adhesives in portions of the optical system are also contemplated. For example, adhesives used to mount and/or maintain a position and/or orientation of a component, including one or more optical fibers, within the systems may be used where the operating conditions of the system are compatible with the selected adhesive (e.g., temperatures below a rated temperature limit of the adhesive).

[0073] It should be appreciated that the present disclosure is not limited by the application of the various components described herein (e.g., stray light baffles, alignment fixtures, mechanical fixtures) in additive manufacturing systems. The components described herein may be employed in any suitable optical system to redirect stray light (e.g., with one or more stray light baffles) and/or position or align optical fibers and associated endcaps (e.g., with one or more alignment and/or mechanical fixtures). For example, linear arrays of optical systems described herein may be employed for applications related to tiled, spectral, and/or coherent beam combining for directed laser energy systems.

[0074] It will be appreciated that any embodiments of the systems, components, methods, and/or programs disclosed herein, or any portion(s) thereof, may be used to form any part suitable for production using additive manufacturing. For example, a method for additively manufacturing one or more parts may, in addition to any other method steps disclosed herein, include the steps of selectively fusing one or more portions of a plurality of layers of precursor material deposited onto the build surface to form the one or more parts. This may be performed in a sequential manner where each layer of precursor material is deposited on the build surface and selected portions of the upper most layer of precursor material is fused to form the individual layers of the one or more parts. This process may be continued until the one or more parts are fully formed.

[0075] Turning to the figures, specific non-limiting embodiments are described in further detail. It should be understood that the various systems, components, features, and methods described relative to these embodiments may be used either individually and/or in any desired combination as the disclosure is not limited to only the specific embodiments described herein.

[0076] FIG. 1 shows, according to some embodiments, a schematic of a fiber optic assembly for an additive manufacturing system. The fiber optic assembly may include one or more optical fibers 120 which may transport laser energy from one or more laser energy sources 102 to the rest of the optical assembly of the system. For example, as shown, the optical fibers may transport laser energy to one or more endcaps 112 disposed on and optically coupled to distal end portions of the associated optical fibers, which may transmit the laser energy to a build surface 140 along a downstream direction DI. It should be understood that a number of components such as optics heads, galvo mirrors, focusing optics, and/or other optical components may be optically disposed between the illustrated endcaps and build surface. In some embodiments, the optical fibers may pass through one or more components 104 (which are represented as a single block in FIG. 1, but may represent multiple different components and/or one or more iterations of different components) which may serve to prepare or modify the optical fibers in a suitable manner. For example, components 104 may include a fiber potting region in which optical fibers are bundled together, one or more buffer stripping elements, and/or one or more cladding or mode stripping elements (which may strip one or more layers of the optical fiber with mechanical or thermal means). In some embodiments, the components 104 may serve to initially align and/or orient the optical fibers 120. In some embodiments, the components 104 may help maintain the fibers 120 in a tensioned configuration to reduce the risk of fiber damage or beam distortion. It should be appreciated that the tensioned configuration may not significantly stress or strain the fibers. In some embodiments, the components 104 include one or more connectors as described previously. It should be appreciated that any suitable components known in the art may be employed, as the present disclosure is not so limited. The various components of the assembly may be positioned in a housing 101 of the optics assembly and/or in a separate housing as the disclosure is not so limited.

[0077] After passing through a first portion of the optical fibers, laser light may subsequently flow through a portion of the one or more optical fibers optically and physically coupled to one or more stray light baffles 106. The baffles 106 may include two portions 106a, 106b, which may serve to clamp or otherwise retain a portion of the optical fibers in place between the two opposing portions of the stray light baffle. In some embodiments, the baffle 106 may include a tapered surface 106c configured to deflect or redirect stray laser light (e.g., backscattered light) away from the optical fibers. For example, as described previously, the tapered surface may expand outwards from the one or more optical fibers in an upstream direction such that a transverse dimension, such as a width and/or thickness, of the stray light baffle may be greater for an upstream portion of the stray light baffle as compared to a downstream portion of the stray light baffle. In either case, when laser light is reflected or back scattered towards the laser energy sources 102 along a second direction D2, the tapered surface 106c of the baffle 106 may be angled relative to the longitudinal axis of the optical fibers or otherwise shaped, to redirect the stray light away from the optical fibers and laser energy sources. Furthermore, a multi-portion baffle to deflect stray light, comprised of multiple bodies, one or more of which may include tapered surfaces, as well as single portion, monolithic baffles, are also contemplated. As described previously, in some embodiments, the baffle 106 may be in thermal communication with a cooling system 107a, or may include a cooling system such as a heat exchanger formed therein, to locally cool the portion of the optical fibers located adjacent to and/or extending through the baffle.

[0078] After passing through the portions of the one or more optical fibers associated with the stray light baffles 106, the laser light may be transmitted through the optical fibers 120 to one or more endcaps 112 optically coupled to and disposed on a distal end portion of the one or more optical fibers. Again, the endcaps and/or optical fibers may be optically coupled to one or more optical elements to transfer light to a build surface 140. The optical fibers 120 may be aligned and/or oriented in one or more corresponding predetermined directions and positions when positioned in one or more alignment fixtures 108, and the one or more endcaps 112 may be aligned and/or oriented in one or more corresponding predetermined directions and positions when positioned in one or more corresponding alignment fixtures 110. In some embodiments, the alignment fixtures 108, 110 may include at least one surface 108a, 110a which may include alignment features (e.g., V-shaped grooves) running parallel along a longitudinal direction of the optical fiber 120. For example, the v- grooves of the fixtures 108, 110 may be parallel to the direction DI shown in FIG. 1. The v- grooved surfaces 108a, 110a may serve to orient the optical fibers and endcaps respectively, relative to one another and/or to the remainder of the assembly. It should be appreciated that the alignment fixture 110 associated with the endcaps, or alternatively with a distal end portion of the optical fibers, may be designed with tighter geometric (e.g., pitch, groove depth, etc.) tolerances than the alignment fixture 108 to ensure accurate alignment of the endcaps and distal end portions of the optical fibers with corresponding predetermined positions. For example, the higher tolerance of the alignment fixture 110 may be used to register the endcaps 112 and distal portions of the optical fibers with one or more optics system of the additive manufacturing system, associated with transferring laser energy to the build surface. Of course, embodiments in which alignment fixtures 108 and 110 are fabricated with the same level of tolerance relative to their geometry are also contemplated. In some embodiments, alignment fixtures may be formed as a monolithic body, rather than the two portion arrangement depicted in FIG. 1.

[0079] As described previously, the additive manufacturing systems of the present disclosure may include one or more mechanical fixtures to help retain at least a portion of the optical fibers aligned and/or positionally fixed relative to the system. In some embodiments, the mechanical fixtures 130a, 130b may apply a bias force to the optical fibers 120 that biases the optical fibers towards the underlying alignment fixture 108 with the optical fibers disposed between the alignment fixture and the at least one mechanical fixture (e.g., piston) to retain the optical fiber in the alignment fixture 108 (e.g., groove). As described previously, in some embodiments, the one or more mechanical fixtures may be thermally conductive and may be in thermal communication with a cooling system 107b to locally cool the portion of the optical fibers located in the baffle.

[0080] As will be described in greater detail below, any of the features described herein to have optional cooling properties (e.g., through active and/or passive cooling) may include one or more integrated cooling channels for cooling with a flowing fluid.

[0081] It should be appreciated that in some embodiments, more than two mechanical fixtures may be employed to fix any desired number of portions of the optical fibers and/or endcaps in a desired position as the present disclosure is not limited by the arrangement or number of mechanical fixtures. In some embodiments, the baffle 106 may include a mechanical fixture configured to orient or positionally fix at least a portion of the optical fibers. It should be appreciated that FIG. 1 depicts a side-view schematic of a fiber optic assembly, and that more than one of any of the depicted components may be employed along the axis normal to the plane of the schematic.

[0082] The optical assemblies described herein are not limited by the arrangement of elements depicted in any of the figures. The optical assemblies may include one or more of the various elements, in any suitable arrangement or orientation. For example, although a single stray light baffle 106 is shown to be downstream of the optical elements 104 and upstream of the alignment fixtures 108, 110 in FIG. 1, embodiments in which more than one stray light baffle is positioned at various locations along the optical system (e.g., downstream of the endcaps 112) are also contemplated.

[0083] In some embodiments, alignment fixtures 108 and 110 may be formed in a housing element of the system, as will be described in greater detail below. The alignment fixtures may be grooved surfaces which may be engaged with an upstream portion of the optical fibers. It should be appreciated that the alignment fixtures 108 and 110 shown in FIG. 1 may refer to different portions of a single surface of a monolithic housing element.

[0084] In some embodiments, mechanical fixtures 130a and 130b aligned with the corresponding alignment fixture (e.g., grooves) may be configured to help positionally fix the optical fibers within the fixtures. In some embodiments, the mechanical fixtures may include one or more pistons extending from a substrate to retain one or more optical fibers independently. In other words, if there is geometric variation (e.g., difference in diameter) along the array of optical fibers 120, the plurality of pistons may function to ensure each fiber is fixed relative to a corresponding portion of an alignment fixture. In some embodiments, each piston may be arranged to bias a single optical fiber towards an underlying portion of an alignment fixture to fix the position of the optical fiber relative to the alignment fixture. However, in other embodiments, each piston may serve to bias or fix more than one optical fiber or endcap.

[0085] The mechanical fixture may be provided in any appropriate form including a leaf spring, spring-loaded pistons, pogo-like pistons, multiple curved fingers, a monolithic compliant or deformable material extending across a width of the fixture (e.g., a thin silver wire), thin curved structures such as curved fingers, and/or any other appropriate structure capable of applying a biasing force to hold the one or more optical fibers or endcaps in contact with the corresponding alignment features of an alignment fixture.

[0086] In some embodiments, the mechanical fixture may include a spherical-tipped probe member may be employed to urge the optical fiber into one or more underlying grooves and retain the fiber in place, reducing the likelihood of both axial and height- wise translation. In other embodiments, the probe members may have flat tips to urge the fibers in place. If the fibers are positioned in v-shaped grooves, the flat-tipped members may help position the fibers, which may have a generally elongated cylindrical shape, consistently deep within the grooves. The flat-tips of the members may have multiple contact points with the optical fibers, such that they may be able to more accurately position the fibers at a desired depth in the grooves. In some embodiments, a mechanical fixture may include more than one row of members. For example, in one embodiment, three rows of spherical, conical, and/or flat-tipped pogo-like piston members (i.e., pogo pins) may be used to reduce the risk of movement of the aligned optical fibers. It should be appreciated that the pogo-like piston members and any other suitable equivalents thereof may be formed with a tip having a geometry and/or surface of any appropriate shape as the disclosure is not limited in this sense. For example, the tip of the pogo-like piston members and any other suitable equivalents thereof may be at least partially flat, conical, spherical, crown-shaped, any appropriate combination thereof, and any other appropriate shape.

[0087] It should be appreciated that although the mechanical fixture is described to bias the optical fibers against an alignment fixture, embodiments where the mechanical fixture works to bias the fibers against a housing component and/or any other suitable support structure, are also contemplated. For example, in some embodiments, three rows of spherical or flat-tipped pogo-like piston members may bias optical fibers arranged in grooves formed in a lower housing component of the system.

[0088] FIG. 2 shows, according to some embodiments, a schematic representation of an additive manufacturing system 300, including a plurality of laser energy sources 302 that deliver laser energy to an optics assembly 304 positioned within a machine enclosure 306. For example, the machine enclosure may define a build volume in which an additive manufacturing process may be carried out. In particular, the optics assembly may direct laser energy 308 towards a build surface 310 positioned within the machine enclosure to selectively fuse powdered material on the build surface. As described in more detail below, the optics assembly 304 may include a plurality of optics defining an optical path within the optics assembly that may transform, shape, and/or direct laser energy within the optics assembly such that the laser energy is directed onto the build surface as an array of laser energy pixels. The optics assembly may be movable within machine enclosure 306 to scan laser energy 308 across build surface 310 during a manufacturing process, though embodiments in which the optics assembly is stationary relative to the build surface are also contemplated. [0089] Additive manufacturing system 300 further includes an optical fiber connector 312 positioned between the laser energy sources 302 and the optics assembly 304. As illustrated, a first plurality of optical fibers 314 may extend between the plurality of laser energy sources 302 and the optical fiber connector 312. In particular, each laser energy source 302 is coupled to the optical fiber connector 312 via a respective optical fiber 316 of the first plurality of optical fibers 314. Similarly, second plurality of optical fibers 318 extends between the optical fiber connector 312 and the optics assembly 304. Each optical fiber 316 of the first plurality of optical fibers 314 is coupled to a corresponding optical fiber 320 of the second plurality of optical fibers 318 within the optical fiber connector. In this manner, laser energy from each of the laser energy sources 302 is delivered to the optics assembly 304 such that laser energy 308 can be directed onto the build surface 310 during an additive manufacturing process (i.e., a build process).

[0090] In some instances, the laser energy sources 302 and optical fiber connector 312 may be stationary relative to a machine enclosure 306. In this manner, the optical fibers 316 of the first plurality of optical fibers 314 may remain substantially stationary throughout a build process, which may aid in avoiding applying stresses to the optical fibers and/or connections or couplings of the optical fibers, which can lead to failure of the optical fibers. Depending on the embodiment, the optical fibers 320 of the second plurality of optical fibers 318 may be movable relative to the stationary optical fiber connector 312 by virtue of their coupling to a movable optics assembly 304. While such movement may impart stresses onto the optical fibers and/or connections or couplings of the optical fibers, aspects described herein may facilitate rapid and simple replacement of the optical fibers 320.

[0091] The additive manufacturing system 300 may also include one or more optical components 360, such as the optical baffle(s), alignment fixture(s), and/or mechanical fixture(s) described above. It should be appreciated that although optical component 360 is shown as a single block positioned between the fiber connectors and the optics assembly, any other suitable arrangement of the optical components or number of features, positioned anywhere along the optical pathway between the laser energy sources 302 and build surface 310 may be implemented.

[0092] FIG. 3 shows a schematic representation of another embodiment of an additive manufacturing system 400. Similar to the embodiment discussed above in connection with FIG. 2, the additive manufacturing system 400 includes a plurality of laser energy sources 402 coupled to the optics assembly 404 within the machine enclosure 406 via the optical fiber connector 412. The first plurality of optical fibers 414 extends between the laser energy sources 402 and the optical fiber connector 412, and the second plurality of optical fibers 418 extends between the optical fiber connector 412 and optics assembly 404. In particular, each optical fiber 416 of the first plurality of optical fibers is coupled to a laser energy source 402 and corresponding optical fiber 420 of the second plurality of optical fibers 418. In the depicted embodiment, optical fibers 416 are coupled to corresponding optical fibers 420 via fusion splices 422 within the optical fiber connector 412. However, embodiments, in which the optical fibers positioned within the connector include endcaps as described herein are also envisioned.

[0093] In the depicted embodiment, the optical fibers 420 of the second plurality of optical fibers 418 are optically coupled to one or more corresponding endcaps 450 disposed on the distal ends of the second plurality of optical fibers. The endcaps 450 are optically coupled to an optics assembly 404 of the system. For example, an alignment fixture 424 configured to define a desired spatial distribution of the optical fibers and endcaps may be used to direct laser energy into the optics assembly. For example, the alignment fixture may comprise a block having a plurality of v-grooves or holes in which each endcap 450 may be positioned and coupled to in order to accurately position the optical fibers and endcaps within the system. Further embodiments and examples of endcaps and alignment fixtures are discussed elsewhere herein.

[0094] The alignment fixture may be used to align each of the optical fibers 420 of the second plurality of optical fibers 418 with one or more corresponding optical components of the optics assembly 404. Consequently, separate alignment operations for each optical fiber 420 (corresponding to each laser energy source 402) may not be required, which may facilitate rapid replacement of the second plurality of optical fibers 418 if needed or otherwise desired (e.g., if one or more optical fibers 420 fails).

[0095] Additionally, FIG. 3 depicts exemplary optics that are optically coupled downstream from the second plurality of optical fibers 418 and the associated endcaps 450. The various optics may be included in the optics assembly to direct laser energy from the second plurality of optical fibers 418 onto the build surface 410, and to form a desired array of laser energy 408 on the build surface. For example, the optics assembly may include beam forming optics such as lenses 426 and 428 (which may be individual lenses, lens arrays, and/or combined macrolenses), mirrors 430, and/or any other appropriate type of optics disposed along the various optical paths between the endcaps and the build surface which may shape and direct the laser energy within the optics assembly. In some embodiments, lenses 426 and 428 may include one or more of micro-lens arrays, and objective lenses. For example, micro-lens arrays may be arranged to collimate the laser energy output from each optical fiber 420 and transform the beam shape of the laser energy, and objective lenses may be arranged to define a focal length for the combined array of laser energy and serve to demagnify or magnify the output from the micro-lens array. In some instances, this demagnification or magnification may be used to adjust the spacing of laser energy pixels in the array of laser energy formed on the build surface. For example, the objective lenses may be arranged to demagnify the array such that there is no spacing between adjacent pixels. Moreover, it should be understood that the current disclosure is not limited to any particular shape, spacing, and/or arrangement of laser energy pixels in the array of laser energy 408 formed on the build surface. For example, the array may be a rectangular array with regularly spaced pixels of laser energy, or the array may be an irregular shape with non- uniform spacing between pixels.

[0096] The additive manufacturing system 400 may also include one or more optical components 460, such as the optical baffle(s), alignment fixture(s), and/or mechanical fixture(s) described above. It should be appreciated that although optical component 460 is shown as a single block positioned between the fiber connectors and the optics assembly, any other suitable arrangement of the optical components or number of features, positioned anywhere along the optical pathway between the laser energy sources 402 and build surface 410 may be implemented.

[0097] FIGs. 4A-4B show two embodiments of an additive manufacturing system. Both embodiments may include structural components to help direct and align optical bundles and/or fibers 120. In some embodiments, the additive manufacturing systems may include components 104 to initially align and/or orient the optical fibers 120, and/or may serve additional functions, such as fiber potting, buffer stripping, cladding, and/or any other suitable function as described earlier. In some embodiments, the additive manufacturing system may include housing components 501A/520A to help secure the various components of the system in place. The systems shown in FIGs. 4A-4B depict an upper housing component 501A and a lower housing component 520A, but embodiments having less than or greater than two housing components are also contemplated. As described previously, in some embodiments, additive manufacturing systems may include active cooling systems to reduce the risk of local heat generation of the system. The active cooling system may utilize a cooling fluid, which may flow into and out of the manufacturing system through ports 527/537, as will be described in greater detail below. In some embodiments, the additive manufacturing systems may employ lids 501C to help secure the active cooling system in place.

[0098] It should be appreciated that the additive manufacturing systems described in FIGs. 4A-15 may employ one or more elements described earlier. For example, the system of FIG. 4B may have a stray light baffle (not shown), mechanical fixtures 530, laser energy sources (not shown), as described previously.

[0099] FIG. 5 depicts an exploded view of the additive manufacturing system of FIG. 4A, with the top housing component removed for improved visibility. As shown in FIG. 5, optical fibers 120 in the form of bundles may be arranged in a component 104 to help direct the bundles into the additive manufacturing system. The fibers 120 may then be distributed along a lower housing 520A using a series of grooves to help secure the fibers in a desired distribution. In some embodiments, the fibers 120 may be secured in place through the use of clamps 516A and retaining elements (e.g., o-rings) 516B, a combination which may be sufficiently strong to retain the fibers in place without exerting undue pressure on to the fibers, as shown in the magnified view of FIG. 6, taken along detail 6 of FIG. 5. The system of FIG. 5 may employ the same stray light baffle 106 as any of the embodiments described earlier to help redirect stray light from the manufacturing system. Similarly, the system may employ one or more mechanical fixtures in the form of spring-loaded pistons for accurately positioning one or more optical fibers without the use of adhesives.

[00100] In some embodiments, an additive manufacturing system may not employ the use of an alignment fixture described previously. Instead, the system may include grooves 513 formed in the housing component 520A, within which the fibers 120 may be seated. The pre-made grooves may align and distribute the fibers in a desired distribution, as shown in FIG. 6. As will be described in greater detail below, the grooves 513 formed in the lower housing 520A may include multiple regions, each having different geometric profiles to further align and lock the fibers 120 in place.

[00101] As shown in FIG. 6, the optical fibers may extend from bundles, in which multiple fibers are arranged in a radial fashion, to the lower housing 520A, in which the fibers are re-oriented in a linear fashion. In some embodiments, clamps 516A may be used to initially re-arrange the fibers from their radial to their linear arrangement. The clamps 516A may abut against projections 516C formed in the lower housing 520A, which may help maintain the clamps at a given height to reduce the risk of excessive force applied to the fibers by the clamps. The clamps 516A may have enough weight to apply a downward pressure to the fibers to facilitate alignment. In some embodiments, the clamps 516A may be magnetic (e.g., either formed at least partially of magnetic material, and/or may include magnetic components) or metallic, which may allow them to interact with one or more of the upper and lower housing. For example, as shown in FIG. 8A, the lower housing 520A may include magnets 516D which may interact with the clamps 516A to maintain the flat orientation of the optical fibers. During assembly of the housing components, the magnetic interaction between the clamps and the housing may allow for more accurate alignment. In some embodiments, the clamps may be staggered, as shown in FIG. 6, to allow for more compact packing across the fibers. In some embodiments, retaining elements 516B (e.g., o- rings) may be used to enhance friction between the weighted clamps 516A and the fibers 120, to further reduce the risk of axial translation of the fibers.

[00102] In some embodiments, the clamps 516A may be used to initially re-orient the fibers 120 from their radial arrangement in the bundle to the serial arrangement along the lower housing. Once the fibers have been secured within the grooves of the lower housing, the clamps may be removed from the lower housing prior to its assembly with the upper housing. In other embodiments, the clamps may stay in place during assembly of the upper and lower housing. In other embodiments still, the clamps may be replaced with another weighted body during assembly of the upper and lower housing.

[00103] FIGs. 7A-7D show a process of forming an upper surface of a lower housing 520 A with a metallic alignment feature. In some embodiments, a metallic component may be arranged in the upper surface of the lower housing which may interact with magnetic element(s) of the upper housing. The interaction between the metal bar (which may be formed of a stainless steel material) and the magnet may facilitate alignment of the upper and lower housing and allow the upper housing to be accurately seated on the lower housing without excessive need for alignment and inspection.

[00104] As shown in FIG. 7A, a cavity 504 is formed centrally along the upper surface of the lower housing 520A. The cavity 504 may accommodate a metallic body 505, which may be seated in the cavity, as shown in FIG. 7B. The body 505 may be sized to the height of the cavity, such that upon placement, the bar may be flush with the upper surface of the lower housing 520A. In some embodiments, a thin layer of epoxy may be applied to the seam between the bar and the cavity sidewalls to limit displacement of the bar within the cavity, although other means of securing the bar in the cavity are also contemplated.

[00105] Once the body 505 is secured within its cavity 504, a series of grooves 513 may be formed (e.g., milled) along at least a portion of the upper surface of the lower housing. The grooves may be formed seamlessly between the lower housing and the body 505. As shown in FIGs. 7C-7D, the grooves may extend from a first portion 213A to a second portion 513B and to a third portion 513C. In some embodiments, the first portion 213A of the grooves may be formed in a portion of the lower housing 520A flush along the upper surface. As shown in the close-up perspective view of FIG. 8A, the upper surface of the grooves may be aligned with the upper surface of the lower housing. When compared to neighboring grooves 513B, the grooves 513A along the first portion may have a greater groove height, although the lower surface of both sets of grooves may be aligned. The increased height of grooves 513A may allow the optical fibers to move freely in the height- wise direction of the grooves, as the height of the grooves 513A may be greater than the diameter of the optical fibers. This difference in size in the height- wise direction may make it easier to align the optical fibers within the grooves 513A. Furthermore, the alignment of the upper surface of the grooves 513A with the upper surface of the lower housing 520A may allow the grooves to be sealed with a weighted object placed on top of the housing. Accordingly, the optical fibers may be retained in place with a temporary weighted object and/or the placement of the upper housing on the lower housing. The optical fibers may be further confined and limited in mobility (in both axial and height-wise directions) as they pass from the grooves 513A to the grooves 513B, as shown in FIG. 8A. Accordingly, the various elements of the lower housing may serve to gently align and orient the optical fibers from their bundle state to the alignment portion 110, as shown in FIG. 7C.

[00106] FIG. 7C depicts an embodiment of a lower housing 520A having grooves 513 associated with 77 optical fibers. In some embodiments, the grooves may accommodate seven bundles of ten fibers each (as represented by the seven groups of ten side-by-side grooves) and one bundle of seven fibers (as represented by the single group of seven side-by- side grooves). FIG. 7D depicts an embodiment of a lower housing 520A having grooves 513 associated with 70 optical fibers. As shown, the grooves may accommodate seven bundles of ten fibers each.

[00107] It should be appreciated that the groove and fiber arrangement of FIGs. 7C and 7D are exemplary, and that any suitable number of grooves and fibers, as well as fibers per bundle, may be employed to deliver the energy to the build surface.

[00108] As shown in FIGs. 7C-7D, the 77 fibers may be re-arranged between a grouped configuration shown closer to the clamped end of the lower housing (e.g., where the clamp projections 516C may be located) to a uniform distribution close to the alignment portion 110. Accordingly, each fiber may be gently bent along the length of the lower housing 520A to achieve the desired re-orientation. It should be appreciated that the fiber bending may be minimal to reduce the risk of signal loss. In the embodiments represented by FIG. 7C, the optical fibers may experience a minimum fiber bend radius of 440 mm. In the embodiments represented by FIG. 7D, the optical fibers may experience a minimum fiber bend radius of 409 mm between the first portion 513A and second portion 513B of the grooves, and a minimum fiber bend radius of approximately 435 mm between the second portion 513B of the grooves and the third portion 513C of the grooves. It should be appreciated that the recited fiber bend radii are exemplary and dependent upon a variety of factors, and therefore non-limiting.

[00109] FIG. 8B shows a perspective close-up view of a lower housing 520A with an integrated metallic body 505. In some embodiments, the body 505 may be attached to the housing 520A prior to the formation of the grooves 513, as previously described. In this way, the channels formed in the housing may be aligned with the channels formed in the body 505, as shown in FIG. 8B. Thus, the optical fibers may not experience any alignment issues associated with the interface between the body 505 and the housing 520A, and may be uniformly oriented along their longitudinal dimension.

[00110] In some embodiments, the body 505 of FIGs. 7C-7D may interact with a temporary metallic clamp. The clamp may be positioned over the body 505, and may help position the optical fibers into grooves of the lower housing. In some embodiments, the clamp may be formed of a metallic material, such that a magnetic attraction between the clamp and the magnetic body may secure the clamp to the lower housing and apply grooveside pressure to the optical fibers. In some embodiments, the clamp may be temporarily arranged to help position the optical fibers, and may be removed during final assembly of the housing elements. In other embodiments, the clamp may be permanently arranged in between the housing elements.

[00111] As shown in FIG. 4B, a secondary upper body 503 may be arranged next to an upper housing 501A, and may serve to help reduce the overall weight of the system. The secondary upper body may be formed of a lightweight material, as will be described in detail below. In some embodiments, the secondary upper body may be sealed against the upper housing to reduce the risk of interfacial vibration and/or fluid leakage. FIGs. 9A-9B depict perspective views of an upper housing 501A according to some embodiments. As shown in FIG. 9A, the upper housing 501A may be accompanied by a lid 501C, which may be used to seal in a cooling system formed of channels formed in a manifold (not shown). The upper housing 501A may further include one or more inlets and outlets 527/537 for the cooling fluid to flow through the one or more cooling channels.

[00112] In some embodiments, the upper housing 501A may include a mechanical fixture 530 which may include one or more resilient or biasing members (e.g., spring-loaded pistons) to help retain the optical fibers against the alignment features (e.g., grooves) of the lower housing (see lower housing 520A in FIGs. 8A-8B). As shown in the bottom perspective view of the upper housing 501A shown in FIG. 9B, the mechanical fixture 530 may include three rows of cavities for housing the biasing members. The biasing members arranged in three lines may further facilitate alignment of the optical fibers at more than one axial location. As will be described in greater detail below, such an arrangement may reduce the risk of in-like misalignment of the optical fibers in the vertical direction. [00113] In some embodiments, the mechanical fixture 530 may be integrated directly within the upper housing 501A. In other embodiments, the mechanical fixture 530 may be a separate entity which may be attached to the upper housing 501A through any suitable means. In other embodiments still, the mechanical fixture may be arranged to be spaced apart from the upper housing 501A, leaving an air gap in between the mechanical fixture and the upper housing 501A to help insulate the mechanical fixture from the remainder of the housing elements, as will be described in greater detail below.

[00114] FIG. 9C shows a perspective view of a mechanical fixture 530 as a standalone element. The mechanical fixture may include more than one row 532 (e.g., three rows) of cavities sized to house resilient elements such as spring-loaded pistons to urge the optical fibers against alignment features (e.g., grooves) in the lower housing.

[00115] As described above, the upper surface of the lower housing may include one or more features to interact with optical fibers. In some embodiments, the lower surface of the lower housing, as well as the upper surface of the upper housing, may both include cooling channels to help reduce the overall temperature of the additive manufacturing system and help reduce the risk of local hot spots, which may be generated by the high energy laser sources.

[00116] In some embodiments, as shown in FIG. 10A, the lower surface of the lower housing 520A and/or the upper surface of the upper housing 501A may include one or more channel 507A which help form a pathway for a cooling system. The channels 507A may be formed within a milled or otherwise indented portion 547, which may accommodate a manifold body 501B, as shown in FIG. 10B.

[00117] In some embodiments, the manifold body 501B may include channels 507B on its upper and lower surfaces, as well as pathways for fluid to flow between the channels on one side of the manifold to the other. For example, cooling fluid may flow from a fluid inlet (e.g., from inlets 527 shown in FIG. 5) into a space formed between the channels of the upper housing 501A and the channels of the manifold, flow through pathways formed in the manifold, and subsequently through spaces formed between the opposing side of the manifold and a lid 501C, as shown in FIG. 10C, which may be used to seal the cooling system and reduce the risk of fluid leakage. In some embodiments, the pathways where the fluid may flow from one side of the manifold to the other may be arranged close to the mechanical fixtures of the additive manufacturing system, where thermal energy may be built up. As will be described in greater detail below, the pathways formed to fluidically connect the upper and lower surfaces of the manifold may have reduced diameters to ensure that fluid passes between the two surfaces at high velocities to help absorb and transport thermal energy from the interface.

[00118] In some embodiments, the various structural elements of the additive manufacturing system may be modified to reduce the overall weight of the system. For example, as shown in FIG. 11, pockets 510 may be removed from the lower 520A or upper 501A housings to reduce the weight of the system. The pockets may represent approximately 12% mass removal from the housing component. In some embodiments, the overall weight of the system may be further reduced through the use of other materials (e.g., lightweight aluminum) and further redesigning the structural elements to optimize mass. In another example, the combination of the housing, the manifold, and the lid on one or more sides of the system may be shortened in a length-wise direction (see FIG. 4B) and replaced by a lightweight metallic body (see secondary upper body 503 in FIG. 4B) to further reduce weight.

[00119] It should be appreciated that both of the lower 520A and upper 501 A housings may be part of the active cooling system. According, each housing may be accompanied by a manifold and lid each, to facilitate cooling on both sides of the manufacturing system. In the case of the lower housing 520A, the manifold 501B may be arranged between a lower surface of the lower housing and a lid 501C. In the case of the upper housing 501A, the manifold 501B may be arranged between an upper surface of the upper housing and a lid 501C. It should be appreciated that the arrangement of fluid channels in the lower and upper housings may be symmetric, or, may be asymmetric.

[00120] FIG. 12 shows a cross-sectional view of the system taken along line 12-12 of FIG. 4A (although a similar view may be taken from FIG. 4A). The cross-sectional view shows a top assembly of a lid 501C, a manifold 501B, and an upper housing 501A. In some embodiments, fluid may flow through channels 501E formed between the upper housing 501 A and the manifold 50 IB, and between the lid 501 C and the manifold 50 IB. The cooling fluid help remove heat from the upper housing 501A, which may be arranged above the various grooves 513A/513B described above of a lower housing 520A, as well as the stray light baffle 105, and the mechanical fixtures 130. In some embodiments, the lower housing may include an integrated metallic body (not shown) which may interact with magnetic elements (not shown), as described previously. As laser energy is pumped into optical fibers (not shown) arranged in the various grooves, hot spots or build up of thermal energy may accumulate about the upper housing. The cooling system may help transport away the thermal energy to maintain consistent system output.

[00121] In some embodiments, the lower housing 520A of the additive manufacturing system may similarly be coupled to a manifold 501B and a lid 501C, forming channels 501E in between for cooling fluid flow. In some embodiments, the lids 501C and the lower 520A and/or the upper 501 A housings may be spaced apart by air gaps 501D for tolerance management and thermal insulation. Furthermore, the manifolds 501B may include one or more fastener holes 501F to fasten the manifold to the lid 501C and/or the housing components. The manifolds 501B may also include sealing grooves 501G to help seal the manifold channels against the lids 501C. It should be appreciated that the securement/sealing arrangement shown in FIG. 12 is exemplary and non-limiting, and other arrangements are also contemplated. In some embodiments, the lids, manifolds, and/or housing components may be secured and/or sealed through the use of adhesives.

[00122] It should be appreciated that there may be an air gap 501D arranged between the mechanical fixture 130 and the upper housing 501A. The Inventors have recognized that without the active cooling systems described herein, the poor thermal convection of air may result in heat accumulation in the mechanical fixture. This build-up of heat may instead need to flow away from the upper housing at the edges of the interface, resulting in a general heating of the housing components. In some embodiments, the active cooling systems described herein may help reduce the thermal build-up of the mechanical fixture. In some embodiments, arrangement of a thermally conductive material (e.g., thermal paste or thermally conductive adhesive material) arranged in the gap 501D between the upper housing 501A and the mechanical fixture 130 may further reduce the accumulation of thermal energy. In some embodiments, as shown in FIG. 12, an air gap 501D may be arranged between the lower lid 501C and the lower housing 520A, which may have a similar function as the air gap 501D arranged between the mechanical fixture 130 and the upper housing 501A. [00123] FIGs. 13A-13B depict two embodiments of a cooling system according to some embodiments. It should be appreciated that the cooling systems shown in FIGs. 13A- 13B represent fluid channels formed in the housing, manifold, and lid components described previously. The direct contact between cooling fluid and the various elements of the additive manufacturing system may allow the fluid to absorb energy directly from the system in an efficient manner without any thermal resistance from tubing or other fluid architecture. [00124] FIG. 13A depicts a cooling system 507 operating in a crossflow configuration. For example, cooling fluid may be introduced into the system through an inlet 527 and split into two pathways 517A/517B to cool each of the upper and lower housings. The arrows of FIG. 13A indicate the direction of fluid flow about the pathway associated with the upper housing. Fluid may follow a similar flow pattern about the pathway associated with the lower housing. As shown, the fluid may first flow to a front edge of the housing, proximate to the mechanical fixture (not shown), and subsequently flow across the system. This fluid flow direction may result in fluid flowing in a direction across the axial direction of the optical fibers. The fluid may then flow to a central portion of the pathway and subsequently flow out of an outlet 537. As the fluid flows through the various portions of the pathway, it may absorb thermal energy from the various interfaces, and carry the thermal energy to the outlet. Continuous flow of fluid may allow the system to be continuously cooled to reduce the risk of thermal energy build-up.

[00125] The Inventors have recognized that such a crossflow arrangement of the cooling flow may result in a thermal gradient across the optical fibers in a tangential direction, which may non-uniformly cool the fibers. Although the cooling system 507 may transport thermal energy away from the system, the temperature gradient across the fibers may result in skewed output and hot spots. The Inventors have therefore recognized the benefits of a cooling system which may cool the optical fibers in a direction aligned with the axial direction of the fibers, instead of across the fibers. Such a cooling system may more uniformly absorb and transport thermal energy away from the fibers.

[00126] FIG. 13B depicts a cooling system 607 having a flow pattern generally aligned with the axial direction of the optical fibers. As shown, cooling fluid may flow through an inlet port 627 and split into two pathways 617A/617B associated with the upper and lower housing components, respectively. The arrows in FIG. 13B indicate fluid flow patterns along the upper pathway 617A, but a similar fluid pattern may be followed in the lower pathway 617B. Fluid may first flow into an upper portion of the pathway, spanning across the full width of the optical fiber array. The fluid may then loop back around at a looped portion 647A, all within the upper pathway, and flow toward the outlet port 537. In some embodiments, the looping may occur at a portion of the fluid pathway proximate to the mechanical fixture (not shown), where thermal energy may be accumulated. The cooling fluid may absorb energy at the looped portion 647A, as well as along other portions of the pathway proximate to the fibers and the upper housing. It should be appreciated that the fanning arrangement of the pathway shown in FIG. 13B may result in more uniform cooling of the surrounding structures (e.g., housing components, optical fibers, etc.) compared to the pathway represented by FIG. 13 A, although both pathways may help to transport thermal energy away from the system.

[00127] Table 1 below outlines operational differences between the cooling system 507 of FIG. 13A and the cooling system 607 of FIG. 13B. As shown in the table, system 607 of FIG. 13B may accommodate approximately 30% more fluid volume than the system 507 of FIG. 13 A. The larger the volume of fluid, the greater the capacity to absorb thermal energy. Thus the increase in fluid volume may indicate a greater efficiency of the fluid system 607 compared to the fluid system 507 within approximately the same spatial footprint.

Table 1 - exemplary cooling properties of the systems represented by FIGs. 13A-13B.

[00128] Similarly, the system 607 may have a greater interfacial surface area in contact with the lower and upper housings, when compared to the system 507. The functional surface area as used herein is associated with the surface area of the fluid with the housing components (e.g., not including interfacial area between the fluid and the lid or the manifold) where there is significant fluid flow. Accordingly, the functional surface area for both systems 507 and 607 does not include surface area surrounding fluid flow into the inlet ports 527/627 and out of the outlet ports 537/637. It should be appreciated that the method of characterizing functional surface area of the two systems is exemplary and other methods of calculating surface area are also contemplated.

[00129] As shown in table 1 above, the system 607 may exhibit an increase of approximately 75% in functional surface area between the fluid and the lower housing, and an increase of approximately 95% in functional surface area between the fluid and the upper housing compared to system 507. The increase in fluid volume and the surface area may result in more efficient cooling of the housings in system 607 relative to system 507 within the same spatial footprint.

[00130] In some embodiments, fluid flow may be further optimized through adjustments in cross-sectional area of the flow path. For example, in system 507 of FIG. 13A, fluid may flow between the inlet and outlet ports through intermediate channels 557. The channels 557 may have a circular cross-section. In contrast, the system 607 of FIG. 13B may employ intermediate channels 657 having a slot-like cross-section. For example, the cross- sectional diameter of intermediate channels 557 from system 507 may be approximately 3.18 mm, resulting in a cross-sectional area of approximately 7.92 mm², while the cross-sectional diameter of the intermediate channels 657 from system 607 may be approximately 2.5 mm in diameter, having a length of approximately 8 mm, resulting in a cross-sectional are of approximately 17.72 mm². Such an increase of cross-sectional area may result in a lower pressure drop along the intermediate channels, which may further reduce thermal gradients within the system 607 compared to the system 507. For example, fluid flowing through system 507 of FIG. 13A may undergo a pressure drop of approximately 32.1 psi between the inlet and outlet ports, whereas fluid flowing through system 607 of FIG. 13B may undergo a significantly lower pressure drop of approximately 6.4 psi between its inlet and outlet ports. It should be appreciated that the pressure drop evaluation is exemplary and other methods of characterizing the pressure drop, and/or any other cooling fluid property, may be employed to evaluate the efficacy of the cooling systems. [00131] FIG. 14 shows another embodiment of an active cooling system 707. Similar to embodiments described previously, cooling fluid may flow from a fluid inlet 727A/727B to a cooling portion 717A/717B associated with the upper or lower housing components, respectively. The fluid may then flow in a front-to-back manner, as described relative to system 607 of FIG. 13B, and may flow out of the system through fluid outlets (e.g., upper fluid outlet 737A). In contrast with the system 607 of FIG. 13B, the system 707 of FIG. 14 may include inlet and outlet ports rearranged in a more compact arrangement. The arrangement of the ports shown in FIG. 14 may align with the overall housing design of FIG. 4B, although other arrangements are also contemplated.

[00132] Table 2 below outlines operational differences between system 607 of FIG. 13B and system 707 of FIG. 14. In some embodiments, system 707 of FIG. 14 may be designed to achieve greater cooling surface area with similar volumes of fluid, when compared to system 607 of FIG. 13B, included in table 2 below.

Table 2 - exemplary cooling properties of the systems represented by FIGs. 13B and 15.

[00133] Any of the housing or structural components described herein may be formed of a suitable material which may be readily formable (e.g., machinable) and thermally conductive to reduce the risk of hot spots. In some embodiments, the housing components may be formed of a pure Copper material. In other embodiments, a Copper alloy, such as a Copper alloyed with Tellurium, may be employed to increase harness, yield strength, and machinability with limited impact to thermal expansion, thermal conductivity, and electrical resistivity in comparison to pure copper.

[00134] FIG. 15 depicts a front view of one embodiment of alignment features which may be employed in any suitable component of an optical system, including, but not limited to one or more portions of the housing, a stray light baffle, and/or any other element of the system. The alignment features may be v-grooves 13, as shown in FIG. 15 to help retain optical fibers 120 or endcaps 112, which may have circular or rounded cross-sections taken along a transverse direction T1-T2, and reduce the risk of transverse movement, which may reduce the accuracy of the optical system and result in system dysfunction or damage. In some embodiments, the v-grooves 13 may be sized and spaced (e.g., width, depth, pitch) to accommodate a specific size of optical fiber 120 and/or endcap 112. In some embodiments, as shown in FIG. 15, a linear array of fibers 120 and/or endcaps 112 may be clamped between two components 10, 12, at least one of which may include alignment features (v- grooves 13). It should be appreciated that embodiments in which both component 10, 12 include alignment features (the same or different) are also contemplated. In other embodiments, a two-dimensional array of fibers 120 and/or endcaps 112 may be clamped between two layers of components 12. This layered arrangement may be continued for any number of layers to provide a desired number of rows in a two-dimensional array. In the above embodiments, the optical fibers 120 and/or endcaps 112 may be aligned in any suitable orientation and/or position within an alignment fixture. For example, the endcaps of the linear array of FIG. 15 may be regularly spaced or irregularly spaced depending on the desired application. It should be appreciated that FIG. 15 schematically depict alignment features, and that embodiments employing more complex features (e.g., rounded corners, holes, etc.) for any suitable number and arrangement of optical fibers and/or endcaps are also contemplated, as the present disclosure is not so limited. The various components of the alignment fixtures and/or portions of baffles may be coupled to one another in any appropriate fashion including, but not limited to, adhesives, fasteners, mechanically interlocking features, welds, and/or any other appropriate type of connection. Additionally, the depicted components as well as the end caps and/or optical fibers may be biased together using one or more mechanical fixtures as described herein.

[00135] In the above embodiment, the use of V-grooves is illustrated. However, any appropriate type of alignment feature, including alignment features with different sizes and/or shape to accommodate different sized and/or shaped endcaps or optical fibers are also contemplated as previously described.

[00136] FIGs. 16A-16G depict perspective illustrations of exemplary endcaps with different shapes that may be coupled to optical fibers for use in an additive manufacturing system, according to certain embodiments. However, it should be understood that endcaps with any appropriate size and/or shape to provide the desired reduced power area density for laser energy transmission may be used as the disclosure is not limited in this fashion.

[00137] In FIG. 16A, an endcap 250 is a cylindrical endcap, which is disposed upon and optically coupled to a distal end 260 of an optical fiber 220. For example, optical fiber 220 may be fused to endcap 250 at distal end 260. In the example of FIG. 16A, endcap 250 is a cylindrical endcap. According to certain embodiments, cylindrical endcaps may aid with the alignment of the associated optical fibers.

[00138] In FIG. 16A, the endcap 250 further comprises a distal surface 262, in some embodiments. A surface area of a distal surface of the endcap may be larger than a transverse cross sectional area of the optical fiber. As noted above, this may provide an increased transmission area of the laser energy within the endcap that is transmitted from the laser energy source. For example, laser energy transmitted from the laser energy source through optical fiber 220 and into endcap 250 may diverge within endcap 250, resulting in an increase in the transmission area of the laser energy transmission. FIG. 16B depicts another embodiment of an optical fiber with an endcap that is similar to FIG. 16A, except that in this embodiment, the endcap 250 disposed on and optically coupled to the distal end of the optical fiber 220 is a prism (e.g., a rectangular prism).

[00139] In the above embodiments, each optical fiber is optically coupled to a separate endcap. However, in some embodiments, two or more optical fibers of a plurality of optical fibers may be coupled to a single endcap. In some embodiments, optically coupling two or more optical fibers to an endcap may advantageously simplify alignment of the optical fibers, e.g., by enforcing the relative positions of the two or more optical fibers using the endcap. FIG. 16C presents such an embodiment. In the depicted embodiment, the distal ends 260 of two optical fibers 220 are coupled to endcap 250. While endcap 250 is coupled to two fibers in the illustrated embodiment, in some embodiments, the number of optical fibers coupled to an endcap in such an embodiment may be at least 2, at least 5, at least 10, at least 20, at least 30, and/or any other appropriate number of optical fibers. In some embodiments, the number of optical fibers coupled to an endcap may be less than or equal to 50, 40, 30, 20, 10, and/or any other appropriate number of optical fibers. Combinations of these ranges are possible.

In some embodiments, every optical fiber in an additive manufacturing system is coupled to a single endcap. In other embodiments, multiple groups of optical fibers that are connected to separate endcaps may also be used.

[00140] FIG. 16D illustrates another exemplary endcap of an optical fiber 220, according to certain embodiments. In this embodiment, the endcap 250 is a microlens (e.g., a convex microlens) that is disposed on and optically coupled to the distal end 260 of the optical fiber 220. While in this embodiment the endcap has the same maximum transverse dimension as the distal end 260 of optical fiber to 220, a surface area of distal surface 262 of the endcap 250 is greater than a cross-sectional area of distal end 260 of the optical fiber 220 (e.g. the transmission area of a core of the optical fiber). In this embodiment, the endcap may function as a microlens, which may advantageously focus transmitted laser energy on a desired focal point as it exits the optical fiber. This may reduce the need for subsequent focusing using microlens arrays and other optical components disposed downstream from the optical fibers. Furthermore, a curvature of the distal surface 262 may reduce the back reflection of laser energy in an upstream axial direction towards the associated laser source. This may advantageously reduce the portion of reflected laser energy reaching the laser energy source. It should be appreciated that in some embodiments, the distal surface 262 may be formed directly from the optical fiber itself. In other words, the optical fiber may be processed (e.g., melting, shaped, polished, cut) to achieve a convex microlens at its distal end. Of course, alternate means of coupling a discrete microlens to a distal end of an optical fiber are also contemplated.

[00141] While the microlens endcap shown in FIG. 16D has the same maximum transverse dimension as the optical fiber, other variations of endcaps comprising microlenses are possible. For example, FIG. 16E presents an exemplary endcap 250 that is disposed on and optically coupled to a distal end of the optical fiber 220 where the endcap comprises a proximal cylindrical portion and a distal convex microlens portion. As with the embodiments described in FIGs. 16A-16D, the distal surface 262 of the endcap 250, which is the external surface of the distal convex microlens portion of endcap 250, has a surface area that is greater than a cross-sectional area of the distal end 260 of the optical fiber 220. Similar to the above, such a construction may increase a transmission area of the transmitted laser energy and focus the transmitted laser energy leaving the endcap. [00142] FIGs. 16F-16G illustrate exemplary endcaps 250 optically coupled to distal ends 260 of optical fibers 220. In some embodiments, as shown in FIG. 16F, the endcap 250 may include a proximal cylindrical portion formed of a core portion 292 surrounded by a cladding portion 294. The endcap 250 may further include a distal surface 262 which may be prismatic or flat, as shown in FIG. 16F, or, in some embodiments, may be convex (e.g., in the form of a microlens), as shown in FIG. 16G. As described previously, the increased surface area of the endcap distal surface 262 relative to the optical fiber distal end 260 may increase a transmission area of the transmitted laser energy and focus the transmitted laser energy leaving the endcap.

[00143] The core portion 292 of the endcap may be formed of any suitable material optically compatible with the laser employed in the additive manufacturing system, such as fused silica. The cladding 294, which may extend around the surface of the core portion 292 in the cylindrical portion may be formed of any suitable material with a lower index of refraction compared to the core. In this way, the interface between the high index core and lower index cladding may reduce the likelihood of laser energy leaking out of the core. The cylindrical portion of the endcap 250 may have any suitable thickness T1 measured along the longitudinal dimension of the optical fiber 220, as shown in FIG. 16F.

[00144] It should be appreciated that the endcaps described herein may have one or more surface treatments and/or coatings to achieve desirable optical properties. For example, the endcaps may include surface treatments to manage the reflections or other means of routing laser energy propagating within the optical fibers. The endcaps may be polished, textured, coated with thin films (including, but not limited to, reflective coatings such as gold, antireflective coatings, and absorptive coatings), combinations thereof, and/or any other surface treatment and/or coating.

[00145] FIGs. 17A-17C depict a schematic top-view of the transmission of laser energy from an array of optical fibers 220 and associated endcaps 250. The fibers and endcaps may be positioned in an alignment fixture 224 (e.g., alignment fixture 108 or 110 of FIG. 1), resting within alignment features 280, which may be v-grooves. The endcaps may be registered against a proximal surface 284 of a transparent structure 282, with the result that the distal-most ends of endcaps 250 are aligned with a desired axial position. However, any appropriate alignment fixture with the one or more optical fibers and endcaps position therein may be used. In this embodiment, laser energy 208 transmitted from endcaps 250 is directed onto a plurality of separate microlenses 276, which are arranged in an array that is aligned with the array of endcaps. FIG. 17B depicts a similar arrangement to FIG. 17A, except that the microlenses are provided in the form of a microlens array where the individual microlenses are formed in a single structure 278. FIG. 17C depicts a similar arrangement to FIG. 17A, except that a macrolens 228 is aligned with the optical fibers and endcaps.

[00146] It should be appreciated that the transparent structure 282 and its associated proximal surface 284 may be formed of and/or coated with materials that exhibit desirable optical properties (e.g., absorption, reflection, stray light routing) and/or thermal properties for thermal management. In some embodiments, the transparent structure 282 may be integrated with an active or passive cooling system to cool the endcaps and/or optical fibers. For example, the transparent structure 282 may include integrated cooling channels where a cooling fluid may flow. In some embodiments, one or more surfaces of the transparent structure 282 may include an antireflective coating. In some embodiments, one or more surfaces of the transparent structure 282 may include patterned features, such as absorber coatings, thin film coatings, reflective coatings, and/or any other feature which may have desirable optical properties.

[00147] While several embodiments of the present disclosure have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means and/or structures for performing the functions and/or obtaining the results and/or one or more of the advantages described herein, and each of such variations and/or modifications is deemed to be within the scope of the present disclosure. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, and/or configurations will depend upon the specific application or applications for which the teachings of the present disclosure is/are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the disclosure described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, the disclosure may be practiced otherwise than as specifically described and claimed. The present disclosure is directed to each individual feature, system, article, material, and/or method described herein. In addition, any combination of two or more such features, systems, articles, materials, and/or methods, if such features, systems, articles, materials, and/or methods are not mutually inconsistent, is included within the scope of the present disclosure.

[00148] The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.”

[00149] The phrase “and/or,” as used herein in the specification and in the claims, should be understood to mean “either or both” of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Other elements may optionally be present other than the elements specifically identified by the “and/or” clause, whether related or unrelated to those elements specifically identified unless clearly indicated to the contrary. Thus, as a non-limiting example, a reference to “A and/or B,” when used in conjunction with open-ended language such as “comprising” can refer, in one embodiment, to A without B (optionally including elements other than B); in another embodiment, to B without A (optionally including elements other than A); in yet another embodiment, to both A and B (optionally including other elements); etc.

[00150] As used herein in the specification and in the claims, “or” should be understood to have the same meaning as “and/or” as defined above. For example, when separating items in a list, “or” or “and/or” shall be interpreted as being inclusive, i.e., the inclusion of at least one, but also including more than one, of a number or list of elements, and, optionally, additional unlisted items. Only terms clearly indicated to the contrary, such as “only one of’ or “exactly one of,” or, when used in the claims, “consisting of,” will refer to the inclusion of exactly one element of a number or list of elements. In general, the term “or” as used herein shall only be interpreted as indicating exclusive alternatives (i.e. “one or the other but not both”) when preceded by terms of exclusivity, such as “either,” “one of,” “only one of,” or “exactly one of.” “Consisting essentially of,” when used in the claims, shall have its ordinary meaning as used in the field of patent law.

[00151] As used herein in the specification and in the claims, the phrase “at least one,” in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed within the list of elements and not excluding any combinations of elements in the list of elements. This definition also allows that elements may optionally be present other than the elements specifically identified within the list of elements to which the phrase “at least one” refers, whether related or unrelated to those elements specifically identified. Thus, as a non-limiting example, “at least one of A and B” (or, equivalently, “at least one of A or B,” or, equivalently “at least one of A and/or B”) can refer, in one embodiment, to at least one, optionally including more than one, A, with no B present (and optionally including elements other than B); in another embodiment, to at least one, optionally including more than one, B, with no A present (and optionally including elements other than A); in yet another embodiment, to at least one, optionally including more than one, A, and at least one, optionally including more than one, B (and optionally including other elements); etc.

[00152] Some embodiments may be embodied as a method, of which various examples have been described. The acts performed as part of the methods may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include different (e.g., more or less) acts than those that are described, and/or that may involve performing some acts simultaneously, even though the acts are shown as being performed sequentially in the embodiments specifically described above.

[00153] Use of ordinal terms such as “first,” “second,” “third,” etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements.

[00154] In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of’ and “consisting essentially of’ shall be closed or semi-closed transitional phrases, respectively, as set forth in the United States Patent Office Manual of Patent Examining Procedures, Section 2111.03.

Claims

1. An additive manufacturing system comprising: at least one laser energy source; an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface; at least one optical fiber optically coupling the at least one laser energy source with the optics assembly; a fiber holder configured to support at least a portion of the at least one optical fiber; and the holder comprising: a first portion comprising a non-magnetic material; a second portion comprising a magnetic material; at least one groove formed in and extending along at least partially across the first portion and the second portion of the holder, wherein the at least one optical fiber is disposed in the at least one groove.

2. The system of claim 1, further comprising a third portion disposed on the first portion and the second portion, wherein the at least one optical fiber is disposed between the third portion and the second portion.

3. The system of any one of the preceding claims, further comprising a magnetic clamp configured to clamp the at least one optical fiber in the at least one groove, wherein the magnetic clamp and the second portion of the holder are configured to be magnetically connected.

4. The system of any one of the preceding claims, wherein the at least one optical fiber is attached to the at least one groove.

5. The system of any one of the preceding claims, wherein the magnetic material is formed at least partially of a ferromagnetic or paramagnetic material.

6. The system of any one of the preceding claims, wherein the non-magnetic material is formed at least partially of a metallic material.

7. The system of any one of the preceding claims, wherein an upper surface of the at least one groove of the first portion is aligned with an upper surface of the at least one groove of the second portion.

8. The system of any one of the preceding claims, further comprising a fourth portion, the at least one groove formed in and extending along at least partially across the fourth portion.

9. The system of claim 8, wherein an upper surface of the at least one groove at the fourth portion is lower than an upper surface of the at least one groove in the first portion.

10. The system of any one of the preceding claims, wherein the at least one groove comprises a plurality of grooves, and wherein the at least one optical fiber comprises a plurality of optical fibers.

11. The system of claim 10, wherein the plurality of grooves re-arrange the plurality of optical fibers from a grouped arrangement at a proximal end of the plurality of grooves to a parallel arrangement at a distal end of the plurality of grooves.

12. An optical fiber holder assembly comprising: a first portion comprising a non-magnetic material; a second portion comprising a magnetic material; at least one groove formed in and extending along at least partially across the first portion and the second portion of the holder, wherein the at least one groove is configured to support at least a portion of at least one optical fiber.

13. The holder of claim 12, further comprising a third portion disposed on the first portion and the second portion, wherein the at least one optical fiber is disposed between the third portion and the second portion.

14. The holder of any one of claims 12-13, further comprising a magnetic clamp configured to clamp the at least one optical fiber in the at least one groove, wherein the magnetic clamp and the second portion of the holder are configured to be magnetically connected.

15. The holder of claim any one of claims 12-14, wherein the at least one optical fiber is attached to the at least one groove.

16. The holder of claim any one of claims 12-15, wherein an upper surface of the at least one groove of the first portion is aligned with an upper surface of the at least one groove of the second portion.

17. The holder of any one of claims 12-16, further comprising a fourth portion, the at least one groove formed in and extending along at least partially across the fourth portion.

18. The holder of any one of claims 12-17, wherein an upper surface of the at least one groove at the fourth portion is lower than an upper surface of the at least one groove in the first portion.

19. The holder of any one of claims 12-18, wherein the at least one groove comprises a plurality of grooves, and wherein the at least one optical fiber comprises a plurality of optical fibers.

20. An additive manufacturing system comprising: at least one laser energy source; an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface; at least one optical fiber optically coupling the at least one laser energy source with the optics assembly; a fiber holder configured to support at least a portion of the at least one optical fiber, the fiber holder comprising at least one channel configured to direct a flow of cooling fluid through the fiber holder, wherein a first portion of the at least one channel is configured to direct the flow of cooling fluid in a first direction that is at least partially parallel to an axial dimension of the at least one optical fiber, and wherein a second portion of the at least one channel is configured to direct flow of cooling fluid in a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber and at least partially opposite the first direction.

21. The system of claim 20, wherein the at least one channel is configured to direct the flow of cooling fluid in a third direction, wherein the third direction is angled relative to the axial dimension of the at least one optical fiber.

22. The system of any one of claims 20-21, wherein the at least one channel is fluidically coupled to an inlet arranged on a first portion of the holder, and wherein the at least one channel is fluidically coupled to an outlet arranged on a second portion of the holder.

23. The system of claim 22, wherein the first portion and the second portion of the holder are arranged on opposite sides of the at least one optical fiber.

24. The system of any one of claims 20-23, further comprising an upper housing configured to be removably coupled to the fiber holder, the upper housing comprising at least one at least one channel configured to direct a flow of cooling fluid through the upper housing, wherein the a first portion of the at least one channel is configured to direct the flow of cooling fluid in a first direction that is at least partially parallel to an axial dimension of the at least one optical fiber, and wherein a second portion of the at least one channel is configured to direct flow of cooling fluid in a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber and at least partially opposite the first direction.

25. The system of any one of claims 20-24, wherein the at least one channel comprises a plurality of channels, and wherein the plurality of channels comprises a plurality of parallel channels.

26. The system of any one of claims 20-25, further comprising a cooling fluid source fluidically coupled to the at least one channel, the cooling fluid source configure to supply cooling fluid to the at least one channel.

27. A method for additive manufacturing, comprising: transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber; flowing cooling fluid through a first portion of at least one channel formed in a fiber holder along a first direction that is at least partially parallel to the axial dimension of the at least one optical fiber; and flowing the cooling fluid through a second portion of the at least one channel formed in the fiber holder along a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber, wherein the second direction is at least partially opposite the first direction.

28. The method of claim 27, further comprising flowing the cooling fluid through a third portion of the fiber holder along a third direction, wherein the third direction is angled relative to the axial dimension of the at least one optical fiber.

29. The method of any one of claims 27-28, further comprising flowing the cooling fluid from an inlet arranged on a first portion of the holder to the at least one channel, and further comprising flowing the cooling fluid from the at least one channel to an outlet arranged on a second portion of the holder.

30. The method of any one of claims 27-29, further comprising: flowing cooling fluid through a first portion of at least one channel formed in an upper housing configured to be removably coupled to the fiber holder along a first direction that is at least partially parallel to the axial dimension of the at least one optical fiber; and flowing the cooling fluid through a second portion of the at least one channel formed in the upper housing along a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber, wherein the second direction is at least partially opposite the first direction.

31. The method of any one of claims 27-30, wherein the at least one channel comprises a plurality of channels, and wherein the plurality of channels comprises a plurality of parallel channels.

32. The method of any one of claims 27-31, further comprising fusing precursor material on a build surface with the laser energy to form one or more parts on the build surface.

33. A part manufactured using the method of any one of claims 27-32.

34. An additive manufacturing system comprising: at least one laser energy source; an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface; at least one optical fiber optically coupling the at least one laser energy source with the optics assembly; and a fiber holder including a first portion and a second portion, wherein the at least one optical fiber is disposed between the first portion and the second portion of the fiber holder; at least one channel configured to direct a flow of cooling fluid through the fiber holder, wherein the at least one channel includes a first portion of the at least one channel disposed in the first portion of the fiber holder and a second portion of the at least one channel disposed in the second portion of the fiber holder, and wherein a portion of the at least one optical fiber is disposed between the first portion of the at least one channel and the second portion of the at least one channel.

35. The system of claim 34, wherein the at least one channel is configured to direct the flow of cooling fluid in a third direction, wherein the third direction is angled relative to the axial dimension of the at least one optical fiber.

36. The system of any one of claims 34-35, wherein the at least one channel is fluidically coupled to an inlet arranged on a first portion of the holder, and wherein the at least one channel is fluidically coupled to an outlet arranged on a second portion of the holder.

37. The system of claim 36, wherein the first portion and the second portion of the holder are arranged on opposite sides of the at least one optical fiber.

38. The system of any one of claims 34-37, further comprising an upper housing configured to be removably coupled to the fiber holder, the upper housing comprising at least one at least one channel configured to direct a flow of cooling fluid through the upper housing, wherein the a first portion of the at least one channel is configured to direct the flow of cooling fluid in a first direction that is at least partially parallel to an axial dimension of the at least one optical fiber, and wherein a second portion of the at least one channel is configured to direct flow of cooling fluid in a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber and at least partially opposite the first direction.

39. The system of any one of claims 34-38, wherein the at least one channel comprises a plurality of channels, and wherein the plurality of channels comprises a plurality of parallel channels.

40. An additive manufacturing system comprising: at least one laser energy source; an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface; at least one optical fiber optically coupling the at least one laser energy source with the optics assembly; and a fiber holder, wherein the fiber holder supports a portion of the at least one optical fiber; a first manifold disposed on a first surface of the fiber holder; a first lid disposed on the first manifold, wherein the first manifold is disposed between the first lid and the fiber holder; and at least one channel having a first portion formed between the first manifold and the fiber holder and a second portion formed between the first manifold and the first lid.

41. The system of claim 40, wherein the at least one channel is fluidically coupled to an inlet arranged on a first portion of the holder, and wherein the at least one channel is fluidically coupled to an outlet arranged on a second portion of the holder.

42. The system of claim 41, wherein the first portion and the second portion of the holder are arranged on opposite sides of the at least one optical fiber.

43. The system of any one of claims 40-42, wherein the at least one channel comprises a plurality of channels, and wherein the plurality of channels comprises a plurality of parallel channels.

44. A method for additive manufacturing, comprising: transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber; flowing cooling fluid through at least one channel of a fiber holder, wherein the fiber holder supports a portion of the at least one optical fiber, the at least one channel formed between the fiber holder and a first manifold of a cooling system; and flowing the cooling fluid along at least one channel formed between the first manifold and a first lid, the first lid configured to be coupled to the fiber holder.

45. The method of claim 44, further comprising flowing the cooling fluid through the at least one channel along a third direction, wherein the third direction is angled relative to the axial dimension of the at least one optical fiber.

46. The method of any one of claims 44-45, further comprising flowing the cooling fluid from an inlet arranged on a first portion of the fiber holder to the at least one channel, and further comprising flowing the cooling fluid from the at least one channel to an outlet arranged on a second portion of the fiber holder.

47. The method of any one of claims 44-46, further comprising: flowing cooling fluid through a first portion of at least one channel formed in an upper housing configured to be removably coupled to the fiber holder along a first direction that is at least partially parallel to the axial dimension of the at least one optical fiber; and flowing the cooling fluid through a second portion of the at least one channel formed in the upper housing along a second direction that is at least partially parallel to the axial dimension of the at least one optical fiber, wherein the second direction is at least partially opposite the first direction.

48. The method of any one of claims 44-47, wherein the at least one channel comprises a plurality of channels, and wherein the plurality of channels comprises a plurality of parallel channels.

49. The method of any one of claims 44-48, wherein the cooling fluid is water.

50. The method of any one of claims 44-49, further comprising fusing precursor material on a build surface with the laser energy to form one or more parts on the build surface.

51. A part manufactured using the method of any one of claims 44-50.

52. An additive manufacturing system comprising: at least one laser energy source; an optics assembly configured to direct laser energy from the at least one laser energy source onto a build surface to form at least one laser energy spot on the build surface; at least one optical fiber optically coupling the at least one laser energy source with the optics assembly; a holder configured to support at least a portion of the at least one optical fiber; and a cylindrical resilient member configured to bias at least the portion of the at least one optical fiber towards the holder, the cylindrical resilient member having a flat tip oriented towards and in contact with the at least one optical fiber.

53. The system of claim 52, wherein the cylindrical resilient member is spring-loaded.

54. The system of any one of claims 52-53, further comprising a plurality of cylindrical resilient members, wherein the plurality of cylindrical resilient members are arranged in at least one row, the at least one row arranged perpendicular to the axial dimension of the at least one optical fiber.

55. The system of claim 54, wherein the at least one row comprises three rows.

56. The system of any one of claims 52-55, wherein the cylindrical resilient member is formed of a thermally conductive material.

57. The system of any one of claims 52-56, further comprising a cooling system comprising at least one channel formed in the holder, the at least one channel configured to direct a flow of cooling fluid through the holder in at least one direction arranged at least partially parallel to the axial dimension of the at least one optical fiber.

58. The system of any one of claims 52-57, wherein the holder comprises at least one groove, and wherein the cylindrical resilient member is configured to vertically bias the at least one optical fiber into the at least one groove.

59. A method for additive manufacturing, comprising: transmitting laser energy from at least one laser energy source along an axial dimension of at least one optical fiber; and biasing at least a portion of the at least one optical fiber towards a holder with a cylindrical resilient member, the holder configured to support the at least a portion of the at least one optical fiber, the cylindrical resilient member having a flat tip oriented towards and in contact with the at least one optical fiber.

60. The method of claim 59, wherein the cylindrical resilient member is spring-loaded.

61. The method of claim 55, further comprising biasing at least a portion of the at least one optical fiber towards the holder with three cylindrical resilient members, wherein the three cylindrical resilient members are arranged in along the axial dimension of the at least one optical fiber.

62. The method of claim 55, wherein the cylindrical resilient member is formed of a thermally conductive material.

63. The method of claim 55, further comprising flowing cooling fluid through at least one channel formed in the holder in at least one direction arranged at least partially parallel to the axial dimension of the at least one optical fiber.

64. The method of claim 55, further comprising vertically biasing the optical fiber towards at least one groove formed in the fiber holder with the cylindrical resilient member.

65. The method of any one of claims 59-64, further comprising fusing precursor material on a build surface with the laser energy to form one or more parts on the build surface.

66. A part manufactured using the method of any one of claims 59-65.