Laser glass welding with an eccentric ferrule

Abstract

An optical assembly may comprise a substrate and a subcarrier, the subcarrier having a front surface defining a plane, a rotational axis crossing the plane defined by the front surface at a first position, and one or more outer surfaces parallel to the rotational axis, and attached to the substrate in one of a plurality of rotational orientations. The optical assembly may further comprise a first optical component disposed at or within the subcarrier, the first optical component having an optical axis crossing the plane defined by the front surface of the subcarrier at a second position. Changing the rotational orientation of the subcarrier may result in a change of distance between the optical axis of the component and the surface of the substrate.

Description

LASER GLASS WELDING WITH AN ECCENTRIC FERRULECROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to U.S. Provisional Application No. 63 / 668,908, which was filed on July 9, 2024, and is titled “LASER GLASS WELDING WITH AN ECCENTRIC FERRULE,” the entirety of which is hereby incorporated by reference herein.FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to assembling components of an optical system, such as by laser welding, and, more specifically, to using rotatable subcarriers to adjust optical component positions.BACKGROUND OF THE DISCLOSURE

[0003] Optical components of various types may be combined to form optical systems that process light. The behavior of light that propagates through an optical system depends not only the types of optical components which the light encounters within the optical system, but also the relative positions and orientations of the optical components. Assembling such optical systems typically includes positioning and bonding of these optical components according to a specified design. It is desirable to achieve precise alignment and bonding of components within an assembly.SUMMARY

[0004] In one example, an optical assembly may comprise: a substrate and a subcarrier, having a front surface defining a plane, a rotational axis crossing the plane defined by the front surface at a first position, and one or more outer surfaces parallel to the rotational axis, and attached to the substrate in one of a plurality of rotational orientations. The optical assembly may further comprise a first optical component disposed at or within the subcarrier, the first optical component having an optical axis crossing the plane defined by the front surface of the subcarrier at a second position.

[0005] In another example, a method of assembling an optical device an optical assembly may comprise contacting at a desired rotational orientation of aplurality of rotational orientations, to a bonding surface disposed at or above a surface of a substrate, one of one or more outer surfaces of a subcarrier, the one or more outer surfaces being parallel to an axis of rotation and being attachable to the bonding surface in the plurality of rotational orientations. The method may further comprise, while the outer surface of the subcarrier is in contact with the surface of the substrate, attaching the subcarrier to the bonding surface.

[0006] In another example, a system for assembling an optical device may comprise a manipulator assembly configured to rotate a subcarrier having one or more outer surfaces parallel to an axis of rotation. The system may further comprise a controller, configured to obtain an indication that the subcarrier is at a desired rotational orientation with respect to a bonding surface, and attach the subcarrier to the bonding surface based at least in part on the indication that the subcarrier is at the desired rotational orientation.

[0007] In another example, an optical device is produced by a method that includes contacting at a desired rotational orientation of a plurality of rotational orientations, to a flat surface of a substrate, one of one or more outer surfaces of a subcarrier, the one or more outer surfaces being parallel to an axis of rotation of the subcarrier and being attachable to the substrate in the plurality of rotational orientations. The method further includes, while the one of the one or more outer surfaces of the subcarrier is in contact with the surface of the substrate and at a desired rotational orientation of the plurality of rotational orientations, attaching the subcarrier to the substrate.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 schematically illustrates a perspective view of an example of a laser welding system.

[0009] FIG. 2A schematically illustrates a side view of an example of an optical assembly.

[0010] FIG. 2B schematically illustrates an example configuration of a subcarrier for an optical component within the optical assembly of FIG. 2A.

[0011] FIGS. 3A-C schematically illustrate adjusting a vertical position of an optical component by rotating an example subcarrier.

[0012] FIGS. 4A, B schematically illustrate example subcarriers having flat surfaces parallel to the rotational axis.

[0013] FIGS. 5A-C schematically illustrate example surface features for registering subcarriers.

[0014] FIGS. 6 A, B schematically illustrate example pedestals for registering subcarriers.

[0015] FIGS. 7A-D schematically illustrate example attachment configurations between subcarriers and axially-aligned optical components.

[0016] FIG. 8 schematically illustrates a five-degree-of-freedom adjustment of an optical component in a subcarrier.

[0017] FIGS. 9 A, B schematically illustrate an example optical assembly.

[0018] FIG. 10 shows a flow chart of an example method for generating an optical assembly.

[0019] Corresponding reference characters indicate corresponding parts throughout the several views. Elements in the drawings are not necessarily drawn to scale. The configurations shown in the drawings are merely examples and should not be construed as limiting in any manner.DETAILED DESCRIPTION

[0020] The disclosure generally relates to aligning and assembling optical and / or micro-optical components to build an optical device. Some embodiments include using a subcarrier to support an optical component, wherein the subcarrier enables adjustment of a distance (e.g., height) of the optical component from a surface of a substrate (e.g., a subcarrier, a sub-carrier, a bench, etc.) prior to attaching the subcarrier to the surface of the substrate or another bonding surface. For example, the subcarrier may be an eccentric ferrule holding a fiber. The ferrule may have a cylindrical shape with a cylindrical lumen disposed at a suitable displacement with respect to an axis of rotation of the ferrule. The lumen may be configured to hold a fiber parallel to but radially displaced from the axis of rotation of the ferrule. When such ferrule is in contact with the substrate, rotating the ferrule changes the distance between the fiber disposed within the lumen and the substrate. The total range of possible distance of the fiber with respect to the substrate achievable by rotating the ferrule is twice the displacement distance between the fiber and the axis of rotation of the ferrule. Bringing the fiber to the desired height prior to attaching the fiber within an optical assembly may include selecting a correspondingrotational orientation of the ferrule. In some examples, the fiber may be rotated within the lumen of and with respect to the ferrule prior to bonding. Thus, the assembly process may include rotating the ferrule to set the separation between the fiber and the substrate and rotating the fiber within the ferrule to set fiber roll position. It should be noted that the discussion of a fiber within an eccentric ferrule can be extended to other optical components housed in an eccentric manner within a rotatable subcarrier. Different subcarrier rotations may then result in different distances between the component and the substrate to which the subcarrier may be attached.

[0021] Examples may relate to optical assemblies including components that are attached via laser welding. The components may include optical components of an optical system that process light. The components may also include other structures that facilitate the positioning of the optical components, such as substrates that provide a mounting base, subcarriers, and pedestals that facilitate attachment of optical components with the substrate at multiple positional and / or orientational degrees of freedom.

[0022] Various bonding techniques may be used to assemble optical systems, such as by using attachment materials between components. For example, adhesives such as ultraviolet curable resins or thermally curable resins (e.g., cured via laser or other light) may be used to attach some or all of the components to each other. However, an adhesive may have a relatively high coefficient of thermal expansion (CTE), and this may require active thermal control. As another example, an adhesive may be formed from a hydroscopic material, so that the adhesive may absorb moisture over time. The absorbed moisture may change a dimension and strength of the adhesive. The absorbed moisture may change one or more properties of the adhesive material over time, which may degrade the adhesive strength. As another example, adhering two components together with suitable placement and adhesion tolerances may require a relatively thin bond line and may require active thermal control of the components.

[0023] In another examples, optical contacting may be used to attach some or all of the components to each other. Optical contacting relies on the van der Waals force to form a stable contact between two contacting (e.g., glass) surfaces. However, optical contacting may require that the surfaces be clean,such as free from particles or debris. As another example, optical contacting may require that the surfaces be relatively smooth, such as having a surface roughness of less than 2 nm. As another example, optical contacting may require that the surfaces be relatively flat, such as having a surface flatness less than 125 nm. As another example, optical contacting may produce a bond between the surfaces that may be weaker than bonds obtained by other adhesion techniques.

[0024] In another example, mechanical mounting and soldering may be used to attach some or all of the components to each other. However, mechanical mounting and soldering may not be suitable for adhering materials that have different coefficients of thermal expansion. In another example, anodic bonding may be used to attach some or all of the components to each other. However, anodic bonding may require numerous fabrication steps and may require a clean room environment. In another example, methods based on thermal diffusion and CO2 laser joining may be used to attach some or all of the components to each other. However, these methods may be slow, requiring several hours of thermal treatments of the components.

[0025] Welding two components via laser welding, such as by using an ultra-short pulse (UPS) laser, may overcome potential drawbacks of other attachment mechanisms, such as weak bonds, aging, slow processing, high cost, and relatively tight tolerances on flatness and cleanliness of the surfaces of the components. Laser welding may avoid use of additional material that may be hydroscopic, use of additional material that may have a relatively high coefficient of thermal expansion, or use of a material that may be absorptive. Laser welding may optionally be used in combination with any other attachment mechanism.

[0026] In laser welding of components, optical elements may focus the pulsed laser to a relatively small area at an interface between the adjacent surfaces of the components. The laser welding may utilize an ultra-fast pulse laser (also referred to as an ultrashort pulse laser) beam focused at a very small area. With each pulse (e.g., generally on the order of femtoseconds to one picosecond), the laser pulse generates some heat due to absorption. The laser may have a relatively high repetition rate, which may allow heat to accumulate locally (e.g., before the heat may dissipate). The heat may accumulate enough toraise the temperature high enough to melt the (e.g., glass) components locally. After the pulsed laser has been applied, the melted material may cool and solidify, thereby forming a bond between the adjacent surfaces of components. This type of laser welding is also referred to herein as “direct” laser welding because the laser is used to weld surfaces of adjacent components without using an adhesive (e.g., that is cured by laser or other light) or other type of separate attachment material. The movement of the laser and / or optical elements may translate the focus of the laser along the interface between the adjacent optical elements to form a bond over a larger surface area, such as in comers of a surface, around a perimeter of the surface, or at discrete locations that are distributed over a surface area of the surface. Away from the interface, such as in an interior of the components or outside the components, the instantaneous power of the pulsed laser is low enough to avoid melting of the components, or damaging any other components, such as electronic components or organic materials.

[0027] Laser welding may produce bonds including a visible artifact at the interface of the welded components. For example, a laser weld may appear as a ripple in the material at the three-dimensional location of the weld. Such an artifact may be readily observed with a microscope or other suitable imaging equipment. In some examples, the weld or welds may be located away from an operational area of the optical component, such that the light processed by the optical component does not pass through laser welds.

[0028] Examples discussed herein relate to configurations and geometries of optical assemblies that may allow optical components to be positioned in space with multiple positional and orientational degrees of freedom, while allowing the optical components to be in contact with adjacent components (e.g., subcarriers, pedestals, etc.) that facilitate positioning of the optical components in a manner that is suitable for laser welding. Examples of suitable optical components may include optical fibers within ferrules, lenses, objective elements, actuatable optical elements, windows, mirrors, dichroic mirrors, focusing elements, filters, beam splitters, sensors, V-groove fiber arrays, photonic integrated circuits (PIC), planar integrated circuits (PLC), and others. In the figures that follow, some of the optical components are depicted as being rectangular or having a rectangularcross section or a rectangular perimeter; it will be understood that any other suitable shapes may also be used.

[0029] In some examples, a subcarrier and / or a pedestal that holds the optical component to the substrate may be used to direct a laser beam through the pedestal to laser weld components to each other (e.g., the optical component to the pedestal, pedestal elements of a pedestal to each other, or the pedestal to the substrate). In other examples, a temporary reflector that is not an attached optical component of the optical assembly may be used to direct a laser beam to laser weld adjacent components. The laser beam may be reflected by the reflector when passed through the reflector (e.g., using total internal reflection (TIR) of the laser beam within a prism) or may be reflected by the reflector (e.g., a mirror) without being passed through the reflector.

[0030] To form the laser weld, additional optical components (not shown) may direct a pulsed laser beam through a specified thickness of material to a focus at an interface between two contacting surfaces of the components.

[0031] In the following discussion, for simplicity, the substrate has a fixed position with respect to a coordinate system { , y, z], while other components, such as pedestals and optical components, are positioned with respect to the substrate and the coordinate system.

[0032] In the following discussion, for simplicity, various portions of various components are referred to as surfaces. A surface of a component, as discussed below, may be in contact with and / or bonded to a surface of another component. It will be understood that the surface at which contact and / or bonding occurs may be only a portion of a side of a component. In some examples, a surface may be entirely flat. In other examples, a surface may include curves or other non-flat features.

[0033] FIG. 1 shows a perspective view of an example of a laser welding system 100. The laser welding system 100 includes a laser light source 152 or, simply, a laser 152. The laser light source 152 may produce a high-energy beam of laser light 154 or, simply, a laser beam 154 that is used to produce laser welds between adjacent surfaces in an optical assembly. In some examples, the laser light source 152 may be an ultrafast pulsed laser light source. The ultrafast pulsed laser may emit optical pulses with a duration of 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, 1, 2 picoseconds or any other suitable duration. The laser light source 152may be a CO2 laser, a neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, a fiber laser, a semiconductor laser, or another suitable laser.

[0034] The laser welding system 100 includes beam-focusing optics 156. The beam-focusing optics 156 may guide the laser beam 154 from the laser light source 152 to the point of welding. The beam-focusing optics 156 may include mirrors, lenses, and other optical components to focus and direct the laser beam 154. For example, the beam-focusing optics 156 may include an objective lens that brings the laser beam 154 to a sharp focus at a specified location in space. As another example, the beam-focusing optics 156 may include a turning mirror that may direct the laser beam 154 from the laser light source 152 to the objective lens. The beam-focusing optics 156 may be enclosed, or may include light baffles, to block stray light from the laser beam 154 for the safety of operators and others in proximity to the laser welding system 100.

[0035] The laser welding system 100 includes a part positioner 158. The part positioner 158 may hold the materials (e.g., components) being welded in place during the welding process. The part positioner 158 may include one or more fixtures, clamps, or robotic arms. The part positioner 158 may move an optical assembly to position the optical assembly with respect to the sharp focus of the laser beam 154. The part positioner 158 may perform its positioning with six degrees of freedom, including: position along an -axis, position along a y- axis, position along a z-axis, rotation about the -axis, rotation about the y-axis, and rotation about the z-axis.

[0036] The laser welding system 100 includes a welding beam positioner 160. The welding beam positioner 160 may reposition the laser beam 154. In some examples, the welding beam positioner 160 may reposition the laser beam 154 with three degrees of freedom, including: position along the -axis, position along the y-axis, and position along the z-axis. In some examples, the welding beam positioner 160 may adjust an angle of incidence of the laser beam 154.

[0037] The example laser welding system 100 includes an alignment camera 162. The alignment camera 162 may provide for optical beam alignment, such as to facilitate checking of beam collimation, beam size and position of beam (in x- and y-axes) to align the beam with an optical axis of the beam-focusing optics 156. The alignment camera 162 may generate image data of the optical beam and / or materials to be welded. The alignment camera 162 may capture a videoimage of the materials being welded in real time, or near-real time. In some examples, the alignment camera 162 may generate part position data that corresponds to a location of the materials being welded. In some examples, the alignment camera 162 may be used to visualize the far field beam formed by the optics to be welded together. For example, when welding together a device that collimates light, the alignment camera 162 may be used to confirm that the beam is collimated and pointed in the correct direction relative to features on the optical device or assembly being made.

[0038] The example laser welding system 100 includes a position sensor 164. The position sensor 164 may measure (directly or indirectly) positions in the ’-direction of the materials being welded, with respect to the beam-focusing optics 156. The position sensor 164 may generate position data that corresponds to the position in the x, y, and / or ’-directions of the materials being welded, with respect to the beam-focusing optics 156. The position sensor 164 may include a camera, an interferometer, a time-of-flight sensor that measures a round-trip time of light from the position sensor 164 to a reflecting element on the part positioner 158 and back to the position sensor 164, and / or a suitable sensor using other suitable measuring technique. The position sensor 164 may be used to confirm parts are in the correct location as well as confirm proper contact between surfaces prior to welding.

[0039] The example laser welding system 100 includes a controller 166.The controller 166 may receive the data from the alignment camera 162 and the position sensor 164. The controller 166 may control at least one of the laser light source 152, the part positioner 158, and the welding beam positioner 160 in response to the received data.

[0040] It should be noted that the example laser welding system 100 is only one possible laser welding system configurations, and many other configurations are possible. For example, the laser beam 154 may, in some examples, be positioned with six degrees of freedom in addition to focus with respect to the optical device or assembly being made. The laser welding system 100 may include beam shaping optics to shape the beam 154 at the welding point. Additionally or alternatively, the laser welding system 100 may include power sensors, temperature sensors, and / or any other suitable sensors communicatively connected to the controller 166. The controller 166 may control at least one ofthe laser light source 152, the part positioner 158, and the welding beam positioner 160 at least in part in response to received sensor data.

[0041] The laser welding system 100 may include or be communicatively connected with an assembly system configured to manipulate and place components into an assembly being made. For example, the laser welding system may include a robotic arm with a optical component holder and / or manipulator to position the optical component being welded and maintain contact with a bonding surface at which the optical component is to be welded. The manipulator may include a gripper, a vacuum holder, or any other suitable device for holding a component.

[0042] FIG. 2A shows a side view of an example optical assembly 200. The optical assembly 200 may be assembled using the example laser welding system 100. The optical assembly 200 is configured to process or perform operations on an optical beam 201. The optical assembly 200 includes a substrate 210 and, directly or indirectly attached to the substrate 210, optical components 230A-D. The substrate 210 has a top surface 212 and a bottom surface 214 and is illustrated positioned upside-down in FIG. 2A, with the z-axis pointing down. The upside-down illustration is consistent with an assembly process using the laser welding system 100 with a laser welding beam 220 delivered in a downward direction through the bottom surface 214 of the substrate 210.

[0043] It should be noted that the substrate 210 may extend to the right and / or to the left of the rectangle representation of the substrate in FIG. 2A. The optical assembly 200 may be a sub-assembly of a larger assembly sharing the substrate 210. In other examples, the substrate 210 may have the limited extent of the rectangle representation of the substrate in FIG. 2A and may serve as a carrier for the optical assembly 200 disposed within a larger optical assembly.

[0044] The optical components 230A-D are configured to process the optical beam 201. The optical components 230A-D may include various types of optical components, such as optical fibers, lenses, filters, polarizers, etc. For convenience or representation, in FIG. 2A, the optical beam 201 is shown entering the optical assembly 200 on the left, moving sequentially through the components 230A-D, and exiting on the right. It should be understood, however, that the optical assembly 200 may include mirrors, prisms, filters, beam splitters, resonant cavities and / or other optical components that mayredirect, split, combine and / or otherwise process light. In other examples, the optical assembly 200 may have optical components that generate light (e.g., lasers, light emitting diodes, etc.), detect light, and / or convert light to other energy (e.g., detectors, photocells, etc.).

[0045] The optical assembly 200 includes pedestals 240 A, B and subcarriers 250A, B for attaching the optical components 230A-C to the substrate 210. The optical component 230D, in contrast, is attached directly (i.e., with no intervening components) to the substrate 210. The attachment may be achieved using, for example, a focused laser welding beam 220 (e.g., laser beam 154). In general, the pedestals 240A, B may be referred to as subcarriers. In the present disclosure, however, the subcarriers 250A, B as well as other “subcarriers” are configured to have an axis of rotation and be attached to bonding surfaces of substrates and / or pedestals in pluralities of rotational orientation, as discussed in more details below. Thus, the rotational aspect is the distinctive feature between “pedestals” and “subcarriers” of the present disclosure.

[0046] The first optical component 230A is attached to the substrate 210 by way of the first subcarrier 250A, with the first optical component 230A attached with the first subcarrier 250A by laser welding (e.g., suitably directed beam 252) or another suitable attachment technique (e.g., adhesive, friction fit, spring, etc.). The first subcarrier 250A is, in turn, attached (e.g., by laser welding or another suitable attachment technique) to the substrate 210. It should be noted that an assembly process may include attaching the subcarrier 250A to the substrate 210 before, after, or contemporaneously with attaching the first optical component 230A to the subcarrier 250A. The second optical component 230B is attached to the pedestal 240A which, in turn, is attached to the substrate 210. The third optical component 230C is attached to the substrate 210 by way of the pedestal 240B and the subcarrier 250B. An assembly process may attach (e.g., using laser welding, adhesive, etc.) the optical component 230C to the subcarrier 250B, the subcarrier 250B to the pedestal 240B, and the pedestal 240B to the substrate 210 in any suitable order. Some or all of the attachments may also be performed in parallel, such as using multiple lasers or a combination of different attachment techniques.

[0047] Generally, the subcarrier 250A, the pedestal 240A, and the combination of the pedestal 240B and subcarrier 250B may each provide one ormore additional degrees of freedom when positioning the respective optical components 230A-C during assembly of the optical assembly 200. The first subcarrier 250A may provide for position adjustment along the z-axis to ensure that light from the first optical component 230A is directed through the second optical component 230B to the third optical component 230C. To provide the z- axis adjustment, the subcarrier 250A may have the optical component 230A disposed eccentrically at or within it. The z-axis adjustment of the optical component 230A may then result from rotating the subcarrier 250A (e.g., roll axis adjustment), as discussed throughout the present disclosure. Furthermore, the first subcarrier 250A may provide for a rotational adjustment in the xy-plane (e.g., yaw axis adjustment) for the first optical component 230A, and / or translational position adjustments in the xy-plane. In some examples, during use of the optical assembly 200, no light may pass through the first subcarrier 250A. In other words, the first subcarrier 250A may help position the first optical component 230A during assembly of the optical assembly 200 but need not provide any optical functions (e.g., process light) during use of the completed optical assembly 200. In other examples, the first subcarrier 250A may provide one or more additional optical functions during use of the completed optical assembly 200 or may pass light without altering or substantially altering the light. As a result of being attached to the substrate 210 via the first subcarrier 250A, the first optical component 230A may be spaced apart from the substrate 210 (e.g., along the z-axis), or otherwise aligned.

[0048] The first pedestal 240A may provide for position adjustment along the z-axis to ensure that light from the first optical component 230A is directed through the second optical component 230B to the third optical component 230C. Furthermore, the first pedestal 240A may provide for a rotational adjustment in the x-y plane for the second optical component 230B. The first pedestal 240A may also provide for a thicker mounting surface for attaching the second optical component 230B to the substrate 210, such as when the second optical component is too thin for effective direct attachment to the substrate 210. In some examples, during use of the optical assembly 200, no light need pass through the first pedestal 240A. In other words, the first pedestal 240A may help position the second optical component 230B during assembly of the optical assembly 200 but need not provide any optical functions (e.g., process light)during use of the completed optical assembly 200. In other examples, the first pedestal 240A may provide one or more additional optical functions during use of the completed optical assembly 200 or may pass light without altering or substantially altering the light. The second optical component 230B may be laser welded to the first pedestal 240A. Other suitable attachment techniques may be used. As a result of being attached with the substrate 210 via the first pedestal 240A, the second optical component 230B may be spaced apart from the substrate 210 (e.g., along the z-axis), or otherwise aligned.

[0049] The second subcarrier 250B in combination with the second pedestal 240B may provide one or more additional degrees of freedom when positioning the third optical component 230C during assembly of the optical assembly 200. In some examples, during use of the optical assembly 200, no light need pass through the second pedestal 240B or the second subcarrier. In other words, the second subcarrier 250B and the second pedestal 240B may help position the third optical component 230C during assembly of the optical assembly 200 but need not provide any optical functions during use of the completed optical assembly 200. In other examples, the second pedestal 240B may provide one or more additional optical functions during use of the completed optical assembly 200 or may pass light without altering or substantially altering the light. The third optical component 230C may be laser welded to the second subcarrier 250B. The second subcarrier 250B may be laser welded to second pedestal 240B. Other suitable attachment techniques may be used. The third optical component 230C may be spaced apart from the substrate 210. Furthermore, the second pedestal 240B, in combination with the second subcarrier 250B, may provide for position adjustment along the z-axis for the third optical component 230C to ensure that light from the second optical component 230B is directed through the third optical component 230C to the fourth optical component 230D, rotational alignment along in the x-y plane (yaw angle), or otherwise facilitate proper alignment within the optical assembly 200. The second subcarrier 250B may provide rotational alignment with respect to the beam 201 of the third optical component 230C. For example, the third optical component 230C may have a rotational asymmetry (i.e., be optically asymmetric, rotationally asymmetric along an optical axis) with respect to the light beam 201. An optically asymmetric optical component may include polarization dependence(e.g., a polarizer, a polarization maintaining fiber, a birefringent crystal, etc.). Additionally or alternatively, an optically asymmetric optical component may include a linear array of optical elements, an astigmatic lens, an angled mirror, a prism, and / or a multicore fiber.

[0050] As discussed in greater detail below, the use of a subcarrier, such as the first subcarrier 250A or the second subcarrier 250B, to mount an optical component, such as the first optical component 230A or the third optical component 230C, to the substrate 210 allows the optical component to be mounted with multiple (e.g., three, four, five, or six) degrees of freedom. A subcarrier may also facilitate proper physical attachment, such as when an optical component is too thin for direct attachment with the substrate 210. Multiple optical components may be positioned in this manner to form an optical system, such as the optical assembly 200. An optical system may include one or more optical components that are mounted via a subcarrier to the substate. Each optical component, which may or may not be mounted via a subcarrier, is positioned to receive light from and / or transmit light to at least one other (e.g., adjacent) optical component.

[0051] The components of the optical assembly 200 may include various types of materials. Components that are used to pass laser light for welding during manufacturing of the optical assembly 200 may include a material that is substantially transparent for the wavelength of the laser light, such as glass, crystal (e.g., semiconductor), or ceramic for laser light having a wavelength of about 1030 nm, although other wavelengths may be used, such as 780 nm. The optical components, which may or may not be used to pass laser welding light during an assembly process, should also be sufficiently transparent for light processed by the optical assembly, such as light having a wavelength of about 780 nm, 1030 nm, 1300 nm or any other suitable wavelength. An example of a suitable wavelength range may include the communication C band (“conventional” band), which includes wavelengths between 1530 nm and 1565 nm. In one example, the substrate, a subcarrier, a pedestal, and / or an optical component may each include glass (e.g., fused silica), crystal, or ceramic. Components that are not used to pass laser light for welding during the manufacturing of the optical assembly may include a material that is opaque for the wavelength of the laser light. For example, the subcarrier or the pedestalmay include a metal or other type of material having low coefficients of thermal expansion when laser light is not transmitted through the pedestal during manufacturing of the optical assembly. In some examples, such as when laser welding light is not transmitted through the optical component during the assembly process for the optical assembly, an optical component may include silicon (e.g., a silicon lens), which is opaque at the welding laser wavelength but not opaque for the light (e.g., which may also be laser light) processed by the optical assembly.

[0052] FIG. 2B schematically illustrates an example configuration of the subcarrier 250A for the optical component 230A within the optical assembly 200 of FIG. 2A. The subcarrier 250A includes a suitable opening 252 (e.g., a channel, a lumen, etc.) within which the optical component 230A may be disposed, as illustrated in FIG. 2A. The subcarrier 250A has a front surface 254A defining a plane 254B and a rotational axis 255 crossing the plane 254B defined by the front surface 254A at a first position 256. The distinction between the front surface 254A and the plane 254B lies at least in part in the fact that the plane 254B subtends a break in the front surface 254A created by the opening 252.

[0053] The subcarrier 250A has an outer surface or, simply, surface 258 parallel to the rotational axis 255. The subcarrier 250A may be a cylindrical ferrule, or, more generally, have a circular projection onto a yz-plane. The surface 258 may be a curved cylindrical surface equidistant from the rotational axis 255. In other examples, the subcarrier 250A may have a polygonal projection onto the yz-plane. The surface 258 may be one of a plurality of surfaces parallel to the rotational axis 255, as discussed, for example, with reference to FIGS. 4A and B below.

[0054] The opening 252 has a centerline 260 crossing, at a second position 262 in the plane 254B defined by the front surface 254A. In the case of an optical component (e.g., optical component 230A of FIG. 2A) substantially centered with respect to the opening 252, the centerline 260 of the opening 252 may correspond to an optical axis of the component. The optical axis of the optical component (e.g., optical component 230A) may cross the plane 254B at the second position 262.

[0055] Generally, the second position 262 need not be different from the first position 256. On the other hand, when the second position 262 is different from the first position 256, rotating the subcarrier 250A with respect to the rotational axis 255 results in moving the second position 262 within the plane 254B. For example, the subcarrier 250A may be an eccentric ferrule, where the opening 252A includes a lumen with a center on centerline 260 which is offset from the rotational axis 255 by a distance of approximately 1 micron, 2 microns, 5 microns, 10 microns. As such, rotating the subcarrier 250A around its rotational axis 255 may adjust a z-position of an optical component (e.g., optical component 230A) disposed within the opening 252A within a range of 2 microns, 4 microns, 10 microns, 20 microns, respectively. When the second position 262 is the same as the first position 256, rotating the subcarrier 250A around the rotational axis 255 may aid in rotating an optical component (e.g., optical component 230A) with an optical axis coincident with the centerline 260 without changing the center z-position of the optical component.

[0056] FIGS. 3A-C schematically illustrate adjusting a vertical position of an optical component 330 by rotating a subcarrier 350 in a manner introduced immediately above regarding subcarrier 250A. It should be noted that the illustrations of FIGS. 3A-C represent front views (i.e., orthogonal to the x-axis), in contrast with the side view (orthogonal to the y-axis) of FIGS. 2A and B. Additionally, in FIGS. 3A-C, the assembly is shown right-side up, meaning a top surface 312 of a substrate 310 is facing up. The subcarrier 350 is disposed on the substrate 310. The substrate 310 has the top surface 312, in contact with the subcarrier 350, and a bottom surface 314. The substrate may be substrate 210, with the top surface 212 and the bottom surface 214. The subcarrier 350 and the optical component 330 may be, for example, subcarrier 250A and optical component 230A, respectively. FIGS. 3A-C and subsequent illustrations reverse the upside-down orientation of FIG. 2A, having the z-axis pointing up along the page.

[0057] The subcarrier 350 is disposed at and in mechanical contact with the top surface 312. A center plane 356, indicated by a dashed line, is parallel to the top surface of 312 and crosses the center of the subcarrier 350. The rotational axis 355 of the subcarrier 350 lies in the center plane 356. In FIG. 3A, the rotational orientation of the subcarrier 350 places the optical component 330above the center plane 356. In FIG. 3B, the rotational orientation of the subcarrier 350 places the optical component 330 below the center plane 356. In FIG. 3C, the rotational orientation of the subcarrier 350 places the optical component 330 at the center plane 356. In some examples, portions of the optical component 330 may lie at either side the center plane at all rotational orientations, with the optical axis of the optical component 330 moving up and down with rotational orientation.

[0058] An example assembly process may include rolling the subcarrier 350 (e.g., along the top surface 312 or prior to contact with the top surface 312) to adjust the distance between the substrate 310 (e.g., the top surface 312) and the optical component 330 (e.g., the optical axis of the optical component 330). To compensate for a lateral shift of the optical component 330 during the rolling along the top surface 312, the assembly process may include sliding the subcarrier 350 along the top surface 312. In other examples, the assembly process may include rotating the subcarrier 350 in place while substantially maintaining the contact point (or contact line) between the subcarrier 350 and the top surface 312. In any case, the assembly process may include laser welding the subcarrier 350 to the substrate 310 after achieving a desired rotational orientation (e.g., to achieve a desired distance D between the optical component 330 and the top surface 312). To that end, the assembly process may include delivering, by a laser welding system, the laser welding beam to one or more contact points between the subcarrier 350 and the top surface 312 which serves as a bonding surface. In some examples, the laser welding system may deliver the laser welding beam through the bottom surface 314 of the substrate 310, as discussed above with respect to FIG. 2A, for example. In other examples, the laser welding system may deliver the laser welding beam through the subcarrier 350, compensating, as needed, for the lensing effect of the subcarrier 350. The laser welding beam may be delivered in any suitable trajectory resulting in a respective shape of a weld. Furthermore, the shape of the weld may depend on a geometry of contact between a subcarrier and a bonding surface. A linear weld may bond a cylindrical subcarrier to a flat surface of a substrate. A double-line weld may bond a cylindrical subcarrier to a v-groove. Two flat surfaces in contact with each other may be bonded with a variety of suitable laser welds (e.g., a zig-zag, a spiral, etc.).

[0059] FIGS. 4A, B schematically illustrate example subcarriers 450A, B having respective flat outer surfaces, or, simply, surfaces 452A, B in contact with the top surface 312 of the substrate 310. The flat surfaces 452A, B are parallel to the respective rotational axes of the subcarriers 450A, B. Optical components 430A, B are disposed, respectively, at or within the subcarriers 450A, B.

[0060] The subcarrier 450A in FIG. 4A has a front surface with a perimeter in the shape of a regular decagon, where the surface 452A is one of ten rectangular surfaces parallel to the axis of rotation. As in FIGS. 3A-C, the illustrations of FIGS. 4A, B are front perspectives along the x-axis. In contrast to FIG. 4A, the subcarrier 450B in FIG. 4B has a front surface with a perimeter in the shape of a regular octagon, where the surface 452B is one of eight rectangular surfaces parallel to the axis of rotation. Generally, a perimeter of the front surface of a subcarrier with a rectangular surface parallel to the rotational axis need not be a regular polygon. The multiple surfaces parallel to the rotational axis may have different areas and the front surface may have an irregular polygon perimeter. Furthermore, a subcarrier may have both curved and flat surfaces. Even more generally, flat surfaces need not be rectangular in shape. An assembly system may use a suitable trajectory of laser welding and a resulting laser weld shape based on the flat surfaces in contact. The system may produce a contour weld, a zig-zag weld, a spiral weld or any other suitable weld shape. The laser weld may be a continuous curve or may include discontinuities. For example, the laser weld may include two or more parallel linear segments.

[0061] The shapes of the subcarriers 450A and B result in having, respectively, ten and eight rotational positions with a flat surface contacting the top surface 312. In the illustrated rotational position of the subcarrier 450A, the optical component 430A is disposed above the rotational axis and the center plane 456 of the subcarrier 450A. Changing the rotational position to contact one of the other nine surfaces to the top surface 312 of the substrate 310 results in a different distance between the optical axis of the optical component 430A and the top surface 312, placing, in some orientations, the optical component 430A below the center plane 456. In the illustrated rotational position of the subcarrier 450B, the optical component 430B is disposed partially above the rotational axis of the subcarrier 450A and the center plane 456. Changing therotational position to contact one of the other seven surfaces to the top surface 312 of the substrate 310 results in a different distance between the optical axis of the optical component 430B and the top surface 312. Thus, the subcarriers 450A, B enable height (i.e., z-axis) control of the respective optical components 430 A, B during an assembly process. Having more sides in a subcarrier may result in finer control of height. While FIGS. 4A, B describe subcarriers 450A, B with ten and eight surfaces parallel to the axis of rotation, alternative subcarriers could have any desired number of surfaces parallel to the axis of rotation.

[0062] In some examples, an optical component with rotational asymmetry (e.g., a quarter-wave plate or any other rotationally asymmetrical component) may be centered around a rotational axis of a subcarrier with a polygonal front facet or cross-section (perpendicular to the x-axis). Rather than height control, such subcarrier may enable indexed rotational control of the optical component during an assembly process.

[0063] FIGS. 5A-C schematically illustrate example surface features for registering subcarriers. In some examples, it may be advantageous to modify a top surface 512A-C of a substrate to include a groove, for example, to register, at least approximately, the subcarrier 350 with a substrate 510. During an assembly process, surface features may stabilize the subcarrier 350 during an assembly process, provide more contact surface for secure attachment of the subcarrier 350, and / or facilitate rotating the subcarrier 350.

[0064] In FIG. 5A, a top surface 512A of a substrate 510A has a triangular groove 513A. The triangular groove 513A may register the subcarrier 350 with respect to the substrate 510A and provide two lines of contact with the surface 512A. Furthermore, the groove 513A may constrain the subcarrier 350 along the y-axis direction as a roller 515 (or another suitable manipulator) rotates the subcarrier 350 by sliding along the top of the subcarrier 350. The rolling of the subcarrier 350 may adjust the height of the optical component 330 disposed at or within the subcarrier 350. An accompanying lateral (y-axis) motion of the optical component 330 may be compensated within the optical assembly by another optical component (e.g., a mirror, a prism, a lens, etc.).

[0065] In FIG. 5B, a top surface 512B of a substrate 510B has a trapezoidal groove 513B. The trapezoidal groove 513B may serve one or more functions ofthe triangular groove 513 A, as described above. Additionally or alternatively, the trapezoidal groove 513B may provide some lateral (y-direction) play for lateral adjustment of the subcarrier 350. Furthermore, the trapezoidal groove 513B may provide a surface orthogonal to the z-axis which may facilitate laser welding of the subcarrier 350 to the substrate 510B.

[0066] In FIG. 5C, a top surface 512C of a substrate 510C has a circular arc groove 513C. The circular arc groove 513C may serve one or more functions of the triangular groove 513 A, as described above. Additionally or alternatively, the circular arc groove 513C may provide a larger contact surface for laser welding of the subcarrier 350 to the substrate 510C.

[0067] FIGS. 6 A, B schematically illustrate example pedestals for registering subcarriers. In some examples, it may be advantageous to add a pedestal to the top surface 312 of the substrate 310. For example, a pedestal 640A in FIG. 6A may aid in registering the subcarrier 350 on the top surface 312 of the substrate 310, constrain lateral movement of the subcarrier 350 during rotation, and / or provide additional stability to an optical assembly.

[0068] In FIG. 6B, a pedestal 640B with a groove may serve a similar function to the triangular groove 513A in FIG. 5A. In other versions, the pedestal 640B may include a groove similar to the grooves described in FIGS. 5B, C. Additionally, or alternatively, the pedestal 640B may serve as a spacer for a height adjustment and / or allow for lateral movement of the subcarrier 350 along the top surface 312 of the substrate 310. For example, during an assembly process, the pedestal 640B may be held against the substrate while the subcarrier 350 is rotated to adjust the height (z-position) of the optical component 330. Subsequently, the subcarrier 350 may be attached to the pedestal 640B. After attaching the subcarrier 350 with the pedestal 640B, the pedestal 640B may be adjusted along the top surface 312. For example, the pedestal 640B may be translated in x-direction, translated in y-direction, and / or rotated about the z-axis (a yaw adjustment) prior to being attached (e.g., laser welded) to the substrate 310. In another example assembly process, the pedestal 640B may be attached to the substrate 310 prior to attaching the subcarrier 350 to the pedestal 640B.

[0069] FIGS. 7A-D schematically illustrate example attachment configurations between subcarriers and axially-aligned optical components. FIGS. 7A and 7B illustrate a side view (along y-axis) and a front view (along x-axis), respectively, of an attachment configuration 700A of an optical component 730A and a subcarrier 750A. The optical components 730A, B are configured to process, respectively, optical beams 701A, B (e.g., beam 201 of FIG. 2). In contrast to configurations in FIGS. 3A-C, 4A, B, 5A-C, and 6A, B, the optical axis of the components 730A, B are, respectively, coincident with the rotational axes of the subcarriers 750A, B. The components 730A, B may have rotational asymmetry with respect to their respective optical axes. Rather than adjusting heights of the optical components 730A, B with respect to the substrate 310, rotating the subcarriers 750A, B may rotationally align the optical components 730A, B.

[0070] In configuration 700A, the optical component 730A is disposed within an opening of the subcarrier 750A and abutted to a window 755A. The optical beam 701 A enters the optical component 730A and exits through the window 755A. In configuration 700B, on the other hand, the optical component 730B is disposed at (e.g., attached to) a front surface 756 of the subcarrier 750B. The optical beam 70 IB enters the optical component 730B through the window 755B.

[0071] FIG. 8 schematically illustrates a five-degree-of-freedom adjustment of the optical component 330 disposed within the subcarrier 350, discussed above with reference to FIGS. 3A-C. The adjustment may be performed during an assembly process using, for example, the laser welding system 100. The subcarrier 350 may be manipulated using a robotic arm terminated with a manipulator which may be a vacuum holder, a gripper, a roller, etc. Different manipulators may be used at different stages of the assembly process.

[0072] FIG. 8 includes a front view 800A (along the x-axis) and a bottom view 800B (along the z-axis). The optical component 330 disposed within the subcarrier 350 may be rotated around its optical axis. Thus, the rotational adjustment 810A of the optical component provides a degree of freedom. The rotation adjustment of the optical component 330 is particularly important when the optical component has a rotational asymmetry. For example, the optical component 330 may be an angle-cleaved fiber, a fiber array, a multicore fiber, a polarization maintaining fiber, a fiber collimator with a beam angled with respect to the rotational axis of the optical component 330, etc. As discussed with reference to FIGS. 3A-C, rotating the subcarrier 350 around its rotationalaxis results in a height (z-axis position) adjustment 810B (with respect to the substrate 310) of the eccentrically disposed optical component 330. For example, the subcarrier 350 may be an eccentric ferrule with the optical component disposed within the lumen of the ferrule offset from the rotational axis of the ferrule. An offset of 0.5 microns, 1 micron, 2 microns, or 5 microns may result in a 1 -micron, 2-micron, 4-micron, or 10-micron range of height adjustment, respectively. The height adjustment 810B is the second degree of freedom.

[0073] Three additional degrees of freedom are illustrated with reference to the top view 800B. The subcarrier 350 may be translated (e.g., by sliding without rotation) along the surface of the substrate 310 in x- and y-directions. Resulting adjustments 810C, D are the third and fourth degrees of freedom. Finally, the subcarrier 350 may be rotated with respect to the z-axis to enable a yaw adjustment 810E. A portion of the subcarrier 350 is shown in FIG. 8B to extend beyond the substrate 310. The portion extended beyond the substrate 310 may facilitate manipulating the subcarrier 350 using, for example, a gripper, as further discussed with reference to FIG. 9B.

[0074] The sixth degree of freedom, which is not illustrated in FIG. 8, may be referred to as pitch with respect to the xy-plane. In many examples, such adjustment may not be necessary. For example, the roll adjustment 810A may position an optical beam in a plane parallel to the xy-plane (orthogonal to the z- axis). The subsequent light processing may be performed in the resulting plane. To a degree that an optical beam may deviate from the xy-plane, a vertical adjustment of a suitable beam-steering lens (or, for example, an adjustment of a beam steering prism or a mirror) may bring the beam to a plane parallel to the xy-plane. Generally, the sixth degree of freedom adjustment of an optical may be performed using a suitable additional optical component.

[0075] When the optical component 330 has been suitably positioned with respect to the substrate 310, the subcarrier 350 may be affixed to the substrate 310, such as by forming a laser weld. In some examples, the subcarrier 350 may be attached to the substrate 310 by a mechanism other than laser welding, such as using an adhesive, optical contacting, etc.

[0076] Similarly, when the optical component 330 has been suitably positioned with respect to the substrate 310, the optical component 330 may belaser welded to the subcarrier 350. In some examples, the optical component 330 may be attached to the subcarrier 350 by a mechanism other than laser welding, such as using an adhesive, optical contacting, etc.

[0077] In some examples, the subcarrier 350 and optical component 330 are held in position on the substrate 310, such as by using robotic arms. After being held in place, the subcarrier 350 is bonded to the substrate 310, and the optical component 330 is bonded to the subcarrier 350. The order of the substrate-to- subcarrier bonding process and the subcarrier-to-optical component bonding process may vary. In one example, a single laser is used to sequentially perform the two bonding processes. In other example, the two bonding processes may be performed in parallel using different lasers and / or laser beams.

[0078] FIGS. 9 A, B schematically illustrate an example optical assembly 900. FIG. 9A is a top view (along the z-axis), and FIG. 9B is a perspective view. The optical assembly 900 is configured to process an optical beam represented as beam sections 901A-C. To that end, the optical assembly 900 includes, attached to a substrate 910 (e.g., substrate 210, 310), optical components 930A- D. The optical components 930A, D are attached to the substrate 910 by way of subcarriers 930A, B, respectively.

[0079] The optical assembly 900 may be a fiber-to-fiber coupling system. The optical components 930A, D are angled fibers. The optical components 930B, C are collimating / focusing lenses. A divergent beam section 901 A exiting the angled fiber optical component 930A is collimated by the lens optical component 930B to form a collimated beam section 90 IB. The collimated beam section 90 IB is focused into the converging beam section 901C by the lens optical component 930C and coupled into the angled fiber optical component 930D. The direction of the beam may be reversed, with the light exiting from the angled fiber optical component 930D and coupling into the angled fiber optical component 930A. Additional components (e.g., polarizers, filters, gratings, apertures, modulators, switches, etc.) may be placed in the collimated beam section 901B to perform additional light processing.

[0080] An angled fiber optical component (e.g., optical components 930A, D) have asymmetry with respect to the optical axes of the fiber in a sense that, due to refraction at the fiber facet, exiting light bends away from the optical axis (e.g., by several degrees). Thus, it is desirable to rotationally align angled fibersduring the assembly process. To that end, the subcarriers 950A, B may be ferrules with lumens within which the angled fiber components 930A, D are disposed. As discussed above (e.g., with reference to FIGS. 7A, B) rotating ferrules may accomplish the rotational alignment of components disposed therein. In the case of the assembly 900, however, rotating the subcarriers 950A, B may be reserved for fine adjustment of height, as discussed in the present disclosure. On the other hand, rotating the fiber components 930A, D within the lumens of the ferrule subcarriers 950A, B may position the optical beam into a desired plane, as discussed with reference to FIG. 8.

[0081] During an assembly process, the components 930B, D and the subcarriers 950A, B may be attached directly to the substrate 910 using laser welding beams 960A-D. The laser welding beams 960A-D may be delivered simultaneously or in any suitable order. The laser welding beams 960A-D may be scanned, for example, as shown by arrow 962, to generate laser weld, such as a linear weld 964. During the assembly, optical components 930A-D an subcarriers 950A, B may be aligned and held (e.g., against the substrate 910) using robotic arms and / or manually operated tools terminated with manipulators. For example, grippers 970A, B may squeeze (e.g., as indicated by arrow 972) the subcarrier 950B and rotate, slide, or otherwise manipulate the subcarrier 950B (e.g., as discussed with reference to FIG. 8).

[0082] The assembly process for aligning and attaching the assembly 900 may need to be performed in an active manner, relying on feedback from measurements of the light processed by the optical components 930A-D. The components 930A-D and the subcarriers 950A, B may be attached by the assembly system in response to receiving respective indications that target translational and rotational positions are reached. In one example, a system (e.g., laser welding system 100) for performing the assembly may rotate the fiber optical component 930A in response to an image generated by a camera (e.g., the alignment camera 162). The image generated by the camera may be indicative of a beamwidth or a pointing direction of the collimated segment of the beam 901B. Furthermore, the assembly system may rotate the ferrule subcarrier 950A to achieve a desired distance (e.g., distance within a threshold of target distance) between the fiber optical component 930A and the bonding surface of the substrate 910. Attaching the ferrule subcarrier 950A to thesubstrate 910 may be based at least in part on obtaining an indication that the fiber optical component 930A is at a desired height (e.g., within the threshold of the target distance with respect to the bonding surface). Obtaining the indication that the fiber optical component 930A is at a desired height may be based at least in part on an image generated by a camera.

[0083] During an active assembly process, a power meter 980 (e.g., configured to measure power collected by the fiber optical component 930A from the fiber optical component 930D) may be used to generate indications of alignment. For example, after the fiber optical component 930A and the subcarrier 950a are attached to the substrate 910, adjustments to positions of at least some of the remaining optical components 930B-D and / or the subcarrier 950B may be based at least in part on data from the power meter 980. For example, an indication that the fiber optical component 930D is within the subcarrier 950B at a desired distance from the substrate 910 may be based on the power measured by the power meter 980. Attaching the fiber optical component 930D to the subcarrier 950B and / or the subcarrier 950B to the substrate 910 may be based at least in part on the indication of power measured by the power meter 980.

[0084] FIG. 10 is a flow chart of an example method 1000 for generating or producing an optical assembly (e.g., optical assembly 200 or 900) or an optical device. The method may use the laser welding system 100.

[0085] At block 1010, the method 1000 includes contacting at a desired rotational orientation of a plurality of rotational orientations, to a flat surface of a substrate, one of one or more outer surfaces of a subcarrier, the one or more outer surfaces being parallel to an axis of rotation of the subcarrier and being attachable to the substrate in the plurality of rotational orientations. In some examples, the bonding surface is a flat surface of the substrate (e.g., surface 212 or 312). In other examples, the bonding surface is a grooved surface of the substrate (e.g., surfaces 512A-C). Still in other examples, the bonding surface is a surface of a pedestal (e.g., pedestal 240B, 640B).

[0086] As discussed in the present disclosure, an optical component may be disposed at or within the subcarrier. Each of the plurality of rotational orientations of the subcarrier may result in a different distance between the optical component and the bonding surface. Furthermore, the desired rotationalorientation may be a rotational orientation that results in a desired distance between the optical component and the bonding surface. In turn, the desired distance may be any distance within a threshold of a target distance. As discussed with reference to FIG. 9, attaching the subcarrier to the bonding surface may be based at least in part on obtaining (e.g., by the controller 166) an indication (e.g., based on an alignment camera or a power meter) that the optical component is within the threshold of the target distance.

[0087] At block 1020, the method 1000 includes, while the one of the one or more outer surfaces of the subcarrier is in contact with the bonding surface and at a desired rotational orientation of the plurality of rotational orientations, attaching the subcarrier to the bonding surface. In some examples, attaching includes laser welding by delivering laser welding light (e.g., as a beam 220, 960A-D) to the bonding surface. The laser welding light may be emitted from an ultra-short-pulsed laser, e.g. with a pulse duration less than a picosecond. The laser welding light may be delivered through the substrate from below the bonding surface, e.g., as discussed with reference to FIG. 2. The laser welding light may be delivered in a linear weld (e.g., linear weld 964).

[0088] The method 1000 may include attaching the optical component to the subcarrier, as discussed above. The method 1000 may be implemented by at least in part by the laser welding system 100 or another suitable system having a manipulator assembly, a controller, and, in some examples, other components to generate indications of alignment. The optical component may have a rotational asymmetry. The method 1000 may further include (e.g., as discussed with reference to FIGS. 8 and 9A, B) adjusting an angle of rotation of the optical component. Still further, the method 1000 may include attaching the optical component to the subcarrier is performed prior to attaching the subcarrier to the bonding surface and after adjusting the angle of rotation of the optical component. In other examples, attaching the optical component to the subcarrier is performed after attaching the subcarrier to the bonding surface. Attaching the optical component to the subcarrier may be performed using an adhesive, laser welding, or another suitable technique.

[0089] As discussed, for example with reference to FIGS. 8, the method 1000 may include adjusting the angle of yaw of the subcarrier prior to attaching the subcarrier to the bonding surface. Additionally or alternatively, the method1000 may include adjusting a translational position (e.g., as in FIG. 8) of the subcarrier prior to attaching the subcarrier to the bonding surface.

[0090] The method 1000 may include rotating the subcarrier while maintaining physical contact with the bonding surface during rotation. Furthermore, the method 1000 may include registering the subcarrier at a bonding surface using a registration structure (e.g., as in FIGS. 5A-C and 6 A, B) disposed at the bonding surface. The method 1000 may include manipulating the subcarrier using a roller, a gripper, a vacuum holder, or another suitable manipulation device. For example, the method 1000 may include (e.g., as in FIGS. 8 and 9B) gripping, using the gripper, a portion of subcarrier overhanging the bonding surface.

[0091] In the description, specific details have been set forth describing some examples. Numerous specific details are set forth to provide a thorough understanding of the examples. It will be apparent, however, to one skilled in the art that some examples may be practiced without some or all of these specific details. The specific examples disclosed herein are meant to be illustrative but not limiting. One skilled in the art may realize other elements that, although not specifically described here, are within the scope of this disclosure.

[0092] Any alterations and further modifications to the described assemblies, apparatuses, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. To avoid needless descriptive repetition, one or more components or actions described in accordance with one illustrative example may be used or omitted as applicable from other illustrative examples. For the sake of brevity, the numerous iterations of these combinations will not be described separately. For simplicity, in some instances the same reference numbers are used throughout the drawings to refer to the same or like parts.

[0093] Additionally, one or more elements in examples of this disclosure, including operations of methods, may be implemented in software to execute on a processor of a computer system such as a control processing system. When implemented in software, the elements of the examples of the present disclosure are essentially the code segments to perform the necessary tasks. The program or code segments may be stored in a processor readable storage medium (e.g., a non-transitory storage medium) or device that may have been downloaded by 1way of a computer data signal embodied in a subcarrier wave over a transmission medium or a communication link. The processor readable storage device may include any medium that may store information including an optical medium, semiconductor medium, and magnetic medium. Processor readable storage device examples include an electronic circuit, a semiconductor device, a semiconductor memory device, a read only memory (ROM), a flash memory, an erasable programmable read only memory (EPROM); a floppy diskette, a CD- ROM, an optical disk, a hard disk, or other storage device. The code segments may be downloaded via computer networks such as the Internet, Intranet, etc. Any of a wide variety of centralized or distributed data processing architectures may be employed. Programmed instructions may be implemented as a number of separate programs or subroutines, or they may be integrated into a number of other aspects of the systems described herein. In some examples, the control system may support wireless communication protocols such as Bluetooth, Infrared Data Association (IrDA), HomeRF, IEEE 802.11, Digital Enhanced Cordless Telecommunications (DECT), ultra-wideband (UWB), ZigBee, and Wireless Telemetry.

[0094] While certain example examples of the present disclosure have been described and shown in the accompanying drawings, it is to be understood that such examples are merely illustrative of and not restrictive to the broad disclosed concepts, and that the examples of the present disclosure not be limited to the specific constructions and arrangements shown and described, since various other modifications may occur to those ordinarily skilled in the art.

Claims

WHAT IS CLAIMED IS:

1. An optical assembly, comprising: a substrate; a subcarrier, having a front surface, a rotational axis crossing a plane defined by the front surface at a first position, and one or more outer surfaces parallel to the rotational axis, and attached to the substrate in one of a plurality of rotational orientations; and a first optical component disposed at or within the subcarrier, the first optical component having an optical axis crossing the plane defined by the front surface of the subcarrier at a second position.

2. The optical assembly of claim 1, wherein the second position is different from the first position.

3. The optical assembly of claim 2, wherein the first position and the second position are separated by at least one micron.

4. The optical assembly of claim 2 or 3, wherein the subcarrier is an eccentric ferrule including a lumen that is offset from the rotational axis, and the first optical component is disposed within the lumen.

5. The optical assembly of any one of claims 1-3, wherein a distance between the substrate and the second position is based at least in part on the one of the plurality of rotational orientations at which the subcarrier is attached to the substrate.

6. The optical assembly of any one of claims 1-3, wherein the subcarrier has cylindrical shape and the one or more outer surfaces parallel to the rotational axis is a curved surface equidistant from the rotational axis.

7. The optical assembly of any one of claims 1-3, wherein the one or more outer surfaces parallel to the rotational axis include at least one flat rectangular surface.

8. The optical assembly of any one of claims 1-3, wherein the first optical component is an optical fiber, and the optical axis of the optical component is an axis of the optical fiber.

9. The optical assembly of claim 8, wherein the optical fiber is a single mode fiber, a multicore optical fiber, or a polarization-maintaining fiber.

10. The optical assembly of claims 8, wherein the optical fiber has an angled facet deviating from the axis of the fiber by at least one degree.

11. The optical assembly of claim 8, wherein the optical fiber is attached to the subcarrier using adhesive.

12. The optical assembly of claim 8, wherein the optical fiber is attached to the subcarrier using laser welding.

13. The optical assembly of any one of claims 1-3, wherein the subcarrier is attached to a surface of the substrate using laser welding.

14. The optical assembly of any one of claims 13, further comprising a laser weld that attaches the subcarrier to the substrate.

15. The optical assembly of claim 14, wherein the laser weld is a linear laser weld.

16. The optical assembly of any one of claims 1-3, wherein the substrate includes a groove or a channel; and the subcarrier is disposed within the groove or the channel.

17. The optical assembly of any one of claims 1-3, wherein the subcarrier is attached to the substrate using a pedestal attached to the substrate.

18. The optical assembly of claim 17, whereinthe pedestal includes a groove or a channel; and the subcarrier is disposed within the groove or the channel.

19. The optical assembly of any one of claims 1-3, wherein the subcarrier is attached to a bonding surface using laser welding.

20. The optical assembly of claim 19, wherein the subcarrier is attached to the substrate with a linear weld along a portion of the one or more outer surfaces of the subcarrier in contact with the substrate.

21. The optical assembly of any one of claims 1-3, wherein the optical assembly includes a second optical component configured to at least one of: i) receive light from the first optical component, or ii) transmit light to the first optical component.

22. The optical assembly of claim 21, wherein the second optical component is attached to a pedestal attached to the substrate.

23. The optical assembly of claim 21, wherein the optical assembly includes collimation optics comprising at least one of the first optical component or the second optical component.

24. The optical assembly of any one of claims 1-3, wherein the first optical component is a lens having rotational symmetry.

25. The optical assembly of any one of claims 1-3, wherein the first optical component has rotational asymmetry.

26. A method of assembling an optical device, the method comprising: contacting a subcarrier at a desired rotational orientation of a plurality of rotational orientations, to a bonding surface disposed at or above a surface of a substrate, one of one or more outer surfaces of a subcarrier; and while the one of the one or more outer surfaces of the subcarrier is in contact with the bonding surface, attaching the subcarrier to the bonding surface.

27. The method of claim 26, wherein the bonding surface is a flat surface of the substrate, a grooved surface of the substrate, or a surface of a pedestal disposed at the substrate.

28. The method of claim 26, wherein attaching includes laser welding by delivering laser welding light to the bonding surface.

29. The method of claim 28, wherein the laser welding light is emitted from an ultra-short-pulsed laser with a pulse duration less than a picosecond.

30. The method of claim 28 or 29 wherein the laser welding light is delivered through the substrate from below the bonding surface.

31. The method of claim 28 or 29, wherein the laser welding light is delivered in a linear weld.

32. The method of claim 26 or 27, wherein an optical component is disposed at or withing the subcarrier.

33. The method of claim 32, wherein: each of the plurality of rotational orientations results in a different distance between the optical component and the bonding surface; and the desired rotational orientation is a rotational orientation that results in a desired distance between the optical component and the bonding surface.

34. The method of claim 33, wherein the desired distance is any distance within a threshold of a target distance.

35. The method of claim 34, wherein attaching the subcarrier to the bonding surface is based at least in part on obtaining an indication that the optical component is within the threshold of the target distance.

36. The method of claim 32, further comprising attaching the optical component to the subcarrier.

37. The method of claim 32, wherein the optical component has rotational asymmetry.

38. The method of claim 37, wherein: the method further comprises adjusting an angle of rotation of the optical component; and attaching the optical component to the subcarrier is performed prior to attaching the subcarrier to the bonding surface and after adjusting the angle of rotation of the optical component.

39. The method of claim 37, wherein: the method further comprises adjusting an angle of rotation of the optical component; and attaching the optical component to the subcarrier is performed after attaching the subcarrier to the bonding surface and after adjusting the angle of rotation of the optical component.

40. The method of claim 32, further comprising: adjusting at least one of i) an angle of yaw, or ii) a translational position of the subcarrier prior to attaching the subcarrier to the bonding surface.

41. The method of claim 36, wherein attaching the optical component to the subcarrier is performed after attaching the subcarrier to the bonding surface.

42. The method of claim 32, wherein the subcarrier is an eccentric ferrule.

43. The method of claim 32, wherein the optical component is an optical fiber.

44. The method of claim 36, wherein attaching the optical component is performed using an adhesive.

45. The method of claim 36, wherein attaching the optical component is performed using laser welding.

46. The method of claims 26 or 27, further comprising rotating the subcarrier while maintaining physical contact with the bonding surface during rotation.

47. The method of claim 46, further comprising: registering the subcarrier at the bonding surface using a registration structure disposed at the bonding surface; and manipulating a subcarrier using a roller.

48. The method of claim 26 or 27, further comprising manipulating the subcarrier using a gripper.

49. The method of claim 48, further comprising gripping, using the gripper, a portion of subcarrier overhanging the bonding surface.

50. The method of claims 26 or 27, further comprising obtaining an indication of desired rotational orientation based on a camera.

51. A system for assembling an optical device, the system comprising: a manipulator assembly configured to rotate a subcarrier having one or more outer surfaces parallel to an axis of rotation; and a controller, configured to: obtain an indication that the subcarrier is at a desired rotational orientation with respect to a bonding surface; and attach the subcarrier to the bonding surface based at least in part on the indication that the subcarrier is at the desired rotational orientation.

52. The system of claim 51, wherein the desired rotational orientation places an optical component disposed at or within the subcarrier at a desired distance from the bonding surface.

53. The system of claim 52, wherein the desired distance is within a threshold distance of a target distance.

54. The system of claim 52 or 53, further comprising a laser, and wherein attaching the subcarrier to the bonding surface includes laser welding by delivering light from the laser to the bonding surface.

55. The system of claim 54, wherein the laser is an ultra- short-pulsed laser.

56. The system of claim 54, wherein delivering the light from the laser includes directing the light from the laser through a substrate and from a side of the bonding surface opposite to the subcarrier.

57. The system of claim 52 or 53, further comprising a camera configured to generate an image of light passing through the optical component, and wherein obtaining the indication is based on the generated image.

58. The system of claim 57, wherein the indication is indicative of the optical component disposed at or within the subcarrier at the desired distance from a substrate.

59. The system of claim 57, wherein the indication is indicative of at least one of: i) pointing direction or ii) beam width of a collimated beam.

60. The system of claim 52 or 53, further comprising a power meter configured to measure power of light received from the optical component, and wherein obtaining the indication is based on the measured power.

61. An optical device produced by: contacting at a desired rotational orientation of a plurality of rotational orientations, to a bonding surface, one of one or more outer surfaces of a subcarrier, the one or more outer surfaces being parallel to an axis of rotation of the subcarrier and being attachable to a substrate in the plurality of rotational orientations; andwhile the one of the one or more outer surfaces of the subcarrier is in contact with the bonding surface and at the desired rotational orientation of the plurality of rotational orientations, attaching the subcarrier to the substrate.

62. The optical device of claim 61, wherein the bonding surface is a flat surface of the substrate, a grooved surface of the substrate, or a surface of a pedestal disposed at the substrate.

63. The optical device of claim 61 or 62, wherein attaching includes laser welding by delivering laser welding light to the bonding surface.

64. The optical device of claim 63, wherein the laser welding light is emitted from an ultra- short-pulsed laser with a pulse duration less than a picosecond.

65. The optical device of claim 63 wherein the laser welding light is delivered through the substrate from below the bonding surface.

66. The optical device of claims 63, wherein the laser welding light is delivered in a linear weld.

67. The optical device of claim 61 or 62, wherein an optical component is disposed at or withing the subcarrier.

68. The optical device of claim 67, wherein: each of the plurality of rotational orientations results in a different distance between the optical component and the bonding surface of the substrate; and the desired rotational orientation is a rotational orientation that results in a desired distance between the optical component and the bonding surface.

69. The optical device of claim 68, wherein the desired distance is any distance within a threshold of a target distance.

70. The optical device of claim 69, wherein attaching the subcarrier to the bonding surface is based at least in part on obtaining an indication that the optical component is within the threshold of the target distance.

71. The optical device of any one of claim 67, wherein assembling the optical device further comprises attaching the optical component to the subcarrier.

72. The optical device of claim 71, wherein the optical component has rotational asymmetry.

73. The optical device of claim 72, wherein producing the optical device further comprises: adjusting an angle of rotation of the optical component; and attaching the optical component to the subcarrier is performed prior to attaching the subcarrier to the bonding surface and after adjusting the angle of rotation of the optical component.

74. The optical device of claim 73, wherein producing the optical device further comprises: adjusting the angle of yaw of the subcarrier prior to attaching the subcarrier to the bonding surface.

75. The optical device of claim 74, wherein producing the optical device further comprises: adjusting a translational position of the subcarrier prior to attaching the subcarrier to the bonding surface.

76. The optical device of claim 71 , wherein attaching the optical component to the subcarrier is performed after attaching the subcarrier to the bonding surface.

77. The optical device of claim 67, wherein the subcarrier is an eccentric ferrule.

78. The optical device of claim 67, wherein the optical component is an optical fiber.

79. The optical device of claim 71, wherein attaching the optical component is performed using an adhesive.

80. The optical device of claim 71, wherein attaching the optical component is performed using laser welding.

81. The optical device of claim 61 or 62, wherein producing the optical device further comprises rotating the subcarrier while maintaining physical contact with the bonding surface during rotation.

82. The optical device of claim 81, wherein producing the optical device further comprises: registering the subcarrier at a bonding surface using a registration structure disposed at the bonding surface; and manipulating the subcarrier using a roller.

83. The optical device of claim 61 or 62, wherein producing the optical device further comprises manipulating the subcarrier using a gripper.

84. The optical device of claim 83, wherein producing the optical device further comprises gripping, using the gripper, a portion of the subcarrier overhanging the bonding surface.

85. The optical device of claim 61 or 62, wherein obtaining an indication of desired rotational orientation based on a camera.

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