Systems and methods for expanded beam optical interconnect

Abstract

Systems and methods for optical interconnects are disclosed. An optical interconnect includes a first optical interface, a second optical interface, and a nanofabricated optical body disposed between the optical interfaces. The nanofabricated optical body transforms an optical field associated with the first optical interface into a spatially expanded optical field and directs the expanded optical field toward the second optical interface. A method for producing the optical interconnect includes providing a first optical interface, determining a spatial position of an optical feature associated with the first optical interface, registering a fabrication coordinate system to the determined spatial position, and nanofabricating optical structures relative to the first optical interface. The nanofabricated optical body may be lithographically aligned to the first optical interface and may enable passive mechanical attachment of the second optical interface without active optical alignment.

Description

IRRA-M06-PCTSYSTEMS AND METHODS FOR EXPANDED BEAM OPTICAL INTERCONNECT CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims the benefit of U.S. Provisional Application No. 63 / 749,844, titled “2D-TO-2D EXPANDED BEAM OPTICAL INTERCONNECT FOR ARBITRARY ARRAY MAPPING”, filed on 27-J AN-2025, which is incorporated in its entireties by this reference.TECHNICAL FIELD

[0002] This invention relates generally to the field of optical interconnects and more specifically to systems and methods for nanofabricated optical interconnects.BACKGROUND OF THE INVENTION

[0003] Optical interconnects are vital to modern data communication systems and integrated photonics, enabling rapid data transfer with minimal signal loss. However, existing solutions face persistent challenges. One significant challenge is the need for precise active alignment during assembly, which drives up costs and complexity. The alignment process requires expensive and time-consuming techniques such as mirrors, precision stages, and postassembly tuning, making scalability difficult for high-volume manufacturing.

[0004] This alignment challenge becomes most acute at fiber-array boundaries, where optical alignment must be maintained simultaneously across many channels. As channel counts increase and photonic integrated circuits are co-packaged alongside electronic ICs, the fiber-to-package interface presents a particularly difficult bottleneck. The limited chip shoreline must simultaneously accommodate optical I / O, electrical routing, thermal management, and mechanical fixtures, creating strong constraints on how optical interfaces can be physically arranged and aligned.

[0005] Moreover, conventional interconnects lack the flexibility to map effectively between arbitrary one-dimensional (1D) or two-dimensional (2D) source and receiver arrays while tailoring optical mode properties. As bandwidth demands continue to increase, fiber technology is evolving toward multicore and multimode formats that enable significantly higher aggregate l of 57IRRA-M06-PCT throughput within a fixed connector footprint. In these surface-emitting configurations, light is launched out of plane from dense two-dimensional arrays of cores or emitters, placing stringent requirements on spatial registration, angular control, and uniformity across channels. Small errors in position or angle at the interface can lead to substantial coupling loss, inter-channel variation, and degraded system performance. These challenges are compounded by the fact that multicore and multimode fiber interfaces are inherently more sensitive to alignment than single-mode, single-core fibers.

[0006] Traditional active alignment approaches do not scale economically with increasing port counts or volumes. The misalignment between architectural ambition and packaging reality has emerged as a key friction point limiting deployment of next-generation photonic systems in data centers, artificial intelligence infrastructure, sensing applications, and emerging compute architectures.

[0007] Thus, there is a need in the optical interconnects field to create new systems and methods for enhanced nanofabricated optical interconnects that address alignment challenges while enabling flexible array mapping across diverse optical interface configurations. This invention provides such a new and useful system and method.BRIEF DESCRIPTION OF DRAWINGS

[0008] FIG. 1 is a schematic of a single-channel optical interconnect system.

[0009] FIG. 2 is a schematic of a multichannel optical interconnect system.

[0010] FIG. 3 is a schematic representation of an optical interconnect system with microlens arrays mapping from fibers to edge couplers.

[0011] FIG. 4 is a diagram of input parameters for optical interconnect design.

[0012] FIG. 5 is a diagram of diffractive lenses with GRIN Fresnel configurations.

[0013] FIG. 6 is a diagram of output parameters for edge coupling.

[0014] FIG. 7 is a schematic of an optical design using aspheric lenses and prisms.

[0015] FIG. 8 is a schematic of an optical design showing ray paths through optical elements.

[0016] FIG. 9 is a schematic of an optical design using plano-convex lenses.

[0017] FIG. 10 is a schematic of an expanded beam connector with a single lens pair.

[0018] FIG. 11 is a schematic of an expanded beam design with lateral and tilt misalignment allowances.

[0019] FIG. 12 is a chart of lateral alignment tolerances.IRRA-M06-PCT

[0020] FIG. 13 is a diagram of a jig with active illumination for alignment during fabrication.

[0021] FIG. 14A is an image of a microlens fabricated on an optical fiber.

[0022] FIG. 14B is a confocal image of a microlens aligned to a fiber core.

[0023] FIG. 15A-15D are diagrams of adaptive alignment for single-channel and multichannel configurations with output beam uniformity data.

[0024] FIG. 16A is an image of microlenses on a fiber array.

[0025] FIG. 16B is a confocal image showing alignment to fiber cores.

[0026] FIG. 17A is a schematic of an edge-coupled clearance connector with a two-lens relay.

[0027] FIG. 17B shows vertical optical clearance at a chip edge.

[0028] FIG. 17C is a comparison of simulation and experimental results.

[0029] FIG. 18 is a diagram of a multicore fiber interface with per-channel adaptive alignment.

[0030] FIG. 19A-19B are schematics of refractive free-space routing configurations.

[0031] FIG. 20A-20B are diagrams of gradient-index optical routing structures.

[0032] FIG. 21 is a schematic of a total internal reflection prism architecture.

[0033] FIG. 22 is a schematic of waveguide-based fan-in and fan-out structures.

[0034] FIG. 23 is a schematic of a diffractive optical routing structure.

[0035] FIG. 24 is a detailed schematic of an optical interface variation with mechanical alignment structures.

[0036] FIG. 25 is a detailed schematic of an optical interface variation with mechanical alignment structures used in a Maxwell kinematic coupling.

[0037] FIG. 26 is a flow diagram of a method for producing an optical interconnect.

[0038] FIG. 27 is a detailed flow diagram for producing an optical interconnect.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0039] The following description of the embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention.1. Overview

[0040] As shown in FIG. 1, the systems and methods for enhanced optical interconnects use a 3D nanofabricated optical solution for arbitrary array mapping between two optical interfaces,IRRA-M06-PCT where microlens arrays may map from an array of fibers to an array of edge couplers on a photonic integrated circuit. The systems and methods may address alignment challenges by embedding optical correction directly into lithographically defined structures, thereby potentially replacing mechanical alignment with optically corrected, passive coupling. Rather than correcting misalignment through mechanical adjustment during packaging, the desired optical correction may be embedded directly into the coupling elements, enabling passive, repeatable, and scalable fiber-array attachment.

[0041] In particular, the systems and methods may provide a 2D-to-2D expanded beam optical interconnect fabricated using a 3D nanofabrication process that enables the creation of arbitrary 3D geometries which may include gradients of refractive index contrast within a nanoporous scaffold material. In particular, by potentially expanding the beam at the interface, the systems and methods may reduce sensitivity to small positional and angular errors during use of the system by increasing the effective mode size during propagation.

[0042] The systems and methods may enable mapping different arrays of optical interfaces, where an interface may be an optical source and / or optical receiver. More specifically, the systems and methods may enable arbitrary mapping of 1D or 2D arrays of optical sources to arbitrary 1D or 2D arrays of optical receivers. Herein, the systems and methods are primarily described as mapping between one array of optical sources to one array of optical receivers. However, the systems and methods may additionally or alternatively map between multiple sets of optical sources and / or receivers.

[0043] The systems and methods may employ lithographically defined adaptive optical alignment at the photonic interface itself. At the single-channel level, lithographically patterned optical elements maybe used to precisely control output beam position and angle. Relative geometry and rotation of the printed elements may compensate for placement and fabrication variations, steering the beam toward a desired principal axis without active tuning. At the multichannel level, the same concept maybe applied on a per-channel basis across dense fiber arrays. Each channel (whether nominally on-axis or off-axis) may receive a tailored optical correction that brings all outputs to a common deflection angle, enabling uniform coupling across high-density arrays. This approach may allow channel-to-channel offsets to be absorbed optically rather than mechanically.

[0044] The systems and methods may also integrate various lenses, prisms, and / or other beam shaping structures within a 3D nanofabricated optical interconnect to facilitate customized transformations of beam geometry, position, and / or mode shape as may be desired for system compatibility. In other words, the systems and methods in addition to facilitatingIRRA-M06-PCT optical connections between sources and receivers may also integrate various optical transformations.

[0045] As shown in FIG. 10, the systems and methods may also create an expanded beam connector design in which a single pair of lenses maps from an array of emitters to an array of receivers, which may allow for greatly reduced alignment tolerances. As shown in FIG. 11, the expanded beam design may provide allowances for lateral and tilt misalignment. The expanded beam design may lead to greater than 100 micrometer diameter expanded beams, which may enable passive alignment of subsequent optical components without sacrificing coupling efficiency.

[0046] The systems and methods may also incorporate or enable other capabilities and / or functionality such as multiplexing (mux) or demultiplexing (demux) by polarization, wavelength, or other optical properties. In one variation, the systems and methods may use polarization-based multiplexing or demultiplexing. In another variation, the systems and methods may use wavelength-based multiplexing or demultiplexing using integrated dispersive elements or grating structures. In yet another variation, the systems and methods may use spatial- or mode-based multiplexing or demultiplexing. An optical interconnect of the system or method may enable beam splitting or combining using lens arrays, prisms, and / or dichroic mirrors.

[0047] The systems and methods may support monolithic optical routing implementations for complex beam path requirements. In one variation, optical routing may be achieved using refractive free-space routing with cascaded optical surfaces. In another variation, optical routing may be achieved using gradient-index (GRIN) structures where the refractive index varies continuously within the routing volume, enabling smooth beam bending without discrete optical surfaces. In yet another variation, optical routing may be achieved using total internal reflection (TIR) prism architectures for efficient large-angle beam redirection. In still another variation, optical routing may be achieved using waveguide-based fan-in and fan-out structures where expanded beams are coupled into guided modes, routed within the structure, and re-emitted at the target interface.

[0048] The systems and methods may be used for implementing optical interconnects which maybe used in a variety of different applications. As described herein, one benefit of the systems and methods is the feature to allow for customization and integration of different functionality. In one example, the systems and methods may be used for optical interconnects used for high-density optical communication systems, including data centers and artificial intelligence infrastructure. In another example, the systems and methods for opticalIRRA-M06-PCT interconnects may be used for photonic integrated circuits (PICs) that benefit from efficient coupling and alignment. The systems and methods may also be useful in advanced sensing systems utilizing arbitrary array geometries.

[0049] The systems and methods may apply across different coupling regimes used in photonic systems. For surface-coupled interfaces (e.g., grating-based and mirror-based approaches in silicon photonics), the systems and methods may enable precise beam shaping and relaxed alignment tolerance. For edge-coupled interfaces (e.g., direct coupling into silicon waveguides), the systems and methods may provide expanded-beam routing and vertical clearance at the chip edge. For surface-emitting interfaces (e.g., VCSELs, micro- LEDs, and multicore or multimode fibers), the systems and methods may enable per-channel adaptive alignment and beam expansion for uniform coupling across dense two-dimensional arrays.

[0050] The systems and methods are primarily described herein in the context of fiber-to-PIC coupling and fiber array interfaces. However, the systems and methods may additionally or alternatively apply to other optical interconnect applications, including co-packaged optics where electronic and photonic integration occurs at the package level, and other applications where passive optical alignment and flexible array mapping are beneficial.

[0051] The systems and methods may provide a number of potential benefits. The systems and methods are not limited to always providing such benefits and are presented only as exemplary representations for how the systems and methods may be put to use. The list of benefits is not intended to be exhaustive, and other benefits may additionally or alternatively exist.

[0052] As one potential benefit, the systems and methods may reduce assembly complexity. The 3D nanofabrication process may eliminate or reduce the need for active alignment, which often necessitates complex and costly equipment. By embedding precise alignment functionality within the lithography process, components may be more easily integrated, thus reducing assembly complexity and reducing production time and costs. The passive alignment enabled by the systems and methods approach may enable repeatable and scalable fiber-array attachment without requiring mechanical adjustment during packaging.

[0053] As another potential benefit, the systems and methods may enhance flexibility and adaptability in optical interconnects. The arbitrary mapping capability may allow for seamless transformation between different geometric configurations of arrays, facilitating integration into a variety of system architectures. For example, the systems and methods may enable mapping between linear arrays and two-dimensional arrays, or between arrays with different pitch geometry, orientation, and / or fan-in or fan-out configurations. This flexibility may support aIRRA-M06-PCT wide range of applications, from photonic integrated circuits to advanced sensing systems. The systems and methods may also allow for integration of various optical elements and functionality within the optical interconnects.

[0054] As another potential benefit, the systems and methods may improve optical performance. The expanded beam design, with its capability to adjust beam geometry and expand the beam, may enhance coupling efficiency between source and receiver arrays. The spatially expanded optical field may have a transverse diameter of at least 100 micrometers, which may enable passive alignment of subsequent optical components without sacrificing coupling efficiency. Enhanced optical properties may be tailored for specific applications through control over refractive index gradients in the scaffold materials. The systems and methods may achieve sub-micron alignment precision relative to the optical interfaces.

[0055] As another potential benefit, the systems and methods may enable per-channel optical correction. Each channel in a multi-channel array (whether nominally on-axis or off-axis) may receive a tailored optical correction that brings all outputs to a common deflection angle. This approach may allow channel-to-channel offsets to be absorbed optically rather than mechanically, enabling uniform coupling across high-density arrays. The per-channel correction may compensate for positional or angular variation independently for each optical channel.

[0056] As another potential benefit, the systems and methods may incorporate multiple optical functionalities within a single monolithic structure. By integrating elements such as polarization-selective structures and wavelength-selective structures directly into the interconnect design, the system may perform advanced multiplexing or demultiplexing functions. In one variation, the systems and methods may use polarization-based multiplexing or demultiplexing. In another variation, the systems and methods may use wavelength-based multiplexing or demultiplexing using integrated dispersive elements or grating structures. In yet another variation, the systems and methods may use spatial- or mode-based multiplexing or demultiplexing. The integration of such functionalities may lead to higher efficiency in data transmission and reduced system complexity.

[0057] As another potential benefit, the systems and methods may enable scalability to high-density optical arrays. The lithographically defined structures maybe fabricated across dense fiber arrays with multiple channels (e.g., at least four, eight, or more optical channels) while maintaining alignment precision for each channel. This scalability may support deployment in data centers, artificial intelligence infrastructure, and other applications requiring high port counts.IRRA-M06-PCT

[0058] As another potential benefit, the systems and methods may provide relaxed alignment tolerances for subsequent assembly steps. As shown in FIG. 11, the expanded beam design variation may provide allowances for lateral and tilt misalignment. As shown in FIG. 12, the expanded beam approach may enable larger lateral tolerances. By expanding the beam at the interface, sensitivity to small positional and angular errors may be reduced. The expanded beam design may enable passive mechanical positioning of optical components without active optical alignment, simplifying manufacturing and reducing costs associated with precision assembly equipment.

[0059] As another potential benefit, the systems and methods may provide vertical clearance at the chip edge for edge-coupled interfaces. The nanofabricated optical body may route the optical field vertically away from an edge of a photonic integrated circuit before directing the optical field to an edge coupler. This vertical routing may accommodate mechanical fixtures, wire bonds, or other components that occupy space near the chip edge while still enabling efficient optical coupling to edge-coupled waveguides.

[0060] As another potential benefit, the systems and methods may provide compatibility across different coupling regimes used in photonic systems. For surface-coupled interfaces (e.g., grating-based and mirror-based approaches), the systems and methods may enable precise beam shaping and relaxed alignment tolerance. For edge-coupled interfaces (e.g., direct coupling into waveguides), the systems and methods may provide expanded-beam routing and vertical clearance. For surface-emitting interfaces (e.g., VCSELs, micro-LEDs, and multicore or multimode fibers), the systems and methods may enable per-channel adaptive alignment and beam expansion for uniform coupling across dense two-dimensional arrays.

[0061] As another potential benefit, the systems and methods may support monolithic optical routing implementations for complex beam path requirements. Optical routing maybe achieved using refractive free-space routing, gradient-index (GRIN) structures, total internal reflection (TIR) prism architectures, or waveguide-based routing within a single nanofabricated structure. This monolithic approach may eliminate the need for discrete optical components and associated alignment challenges, reducing overall system complexity.2. System

[0062] As shown in FIG. 1, an optical interconnect system 100 may include a first optical interface 110, a second optical interface 120, and a nanofabricated optical body 130 disposed between the first optical interface 110 and the second optical interface 120. The nanofabricated optical body 130 may be configured to transform an optical field associated with the first opticalIRRA-M06-PCT interface no into a spatially expanded optical field and to direct the spatially expanded optical field toward the second optical interface 120. In particular, the optical interconnect system 100 may be used for forming a 2D-to-2D expanded beam optical interconnect. As shown in FIG. 1, the optical interconnect system 100 may interface with an optical connector, where a set of two microlens arrays may map from an array of fibers to an array of edge couplers on a photonic integrated circuit.

[0063] As shown in FIG. 4, various input parameters may be considered when designing the optical interconnect. The first optical interface 110 and the second optical interface 120 may each include one or more optical channels 112, 122, where each optical channel represents an independent optical path. The first optical interface 110 may function as an optical source interface and the second optical interface 120 may function as an optical receiver interface, or vice versa. In a variation with multiple optical channels, the optical channels may be arranged in a one-dimensional configuration or two-dimensional configuration, forming an array of optical channels, or alternatively in any suitable combination of a set of channels.

[0064] In one variation, the nanofabricated optical body 130 may be lithographically aligned to the first optical interface 110. Lithographic alignment may enable sub-micron positioning precision of the optical structures relative to the optical channels 112 of the first optical interface 110. The system may include alignment features that facilitate optical alignment of one or more optical elements during the lithographic process of nanofabrication. By registering the fabrication coordinate system to the spatial position of optical features at the first optical interface 110, the nanofabricated optical body 130 may embed optical correction directly into the coupling elements. This approach may replace mechanical alignment with optically corrected, passive coupling, enabling repeatable and scalable attachment of the second optical interface 120 without active optical alignment during assembly.

[0065] In another variation, the nanofabricated optical body 130 may include optical structures 134 formed by depositing materials within a three-dimensional nanoporous scaffold 132. The nanoporous scaffold 132 may include aerogels, polymeric scaffolds, porous glass, porosified semiconductor materials, and / or other porous materials. The optical structures 134 may be formed by two-photon polymerization or multiphoton absorption within the nanoporous scaffold 132, enabling the creation of arbitrary three-dimensional geometries with gradients of refractive index contrast. The deposited materials may include polymers, metal chalcogenides, semiconductors, metals, and / or other fill materials selected based on desired optical properties.

[0066] In yet another variation, the nanofabricated optical body 130 may include channelspecific optical correction structures configured to independently compensate for positional orIRRA-M06-PCT angular variation for each of a plurality of optical channels. As shown in FIG. 15A, at the singlechannel level, lithographically patterned optical elements may precisely control output beam position and angle, where relative geometry and rotation of the printed elements compensate for placement and fabrication errors. As shown in FIG. 15B, at the multi-channel level, the same concept maybe applied on a per-channel basis across dense arrays. Each channel (whether nominally on-axis or off-axis) may receive a tailored optical correction that brings all outputs to a common deflection angle, enabling uniform coupling across high-density arrays. As shown in FIG. 15C and FIG. 15D, quantified output beam uniformity across channels may demonstrate consistent beam placement within a target aperture along with representative output mode profiles for individual channels. This approach may allow channel-to-channel offsets to be absorbed optically rather than mechanically.

[0067] The nanofabricated optical body 130 may function as a relay that maps the optical field from a first localized optical mode at the first optical interface 110 to a second localized optical mode at the second optical interface 120 through the spatially expanded optical field. The relay architecture may include an expansion region that collimates and expands a guided optical mode into an expanded optical beam, and a compression region that focuses the expanded optical beam toward the second optical interface 120. Different optical elements may be implemented within the nanofabricated optical body 130 to allow adjustment of the mode shape, geometry, and / or position to enhance coupling efficiency with the second optical interface 120. The expanded optical beam may have a diameter of greater than 100 micrometers, which may enable passive alignment of subsequent optical components without sacrificing coupling efficiency.

[0068] As shown in FIG. 2, the optical interconnect system too may enable mapping between different array geometries using per-channel optical structures within the nanofabricated optical body 130. The first optical interface 110 may have a first array geometry and the second optical interface 120 may have a second array geometry that differs from the first array geometry in pitch, orientation, or spatial arrangement. In one variation, the first array geometry may include a linear array, and the second array geometry may include a two-dimensional array, or vice versa. In another variation, the first array geometry and the second array geometry may have different pitch spacings. The nanofabricated optical body 130 may be configured to route optical channels between these different geometries, enabling fan-in or fanout configurations as well as arbitrary spatial rearrangements.

[0069] The first optical interface 110 and the second optical interface 120 may function as connection points within the optical interconnect system 100. The optical interfaces 110 or 120IRRA-M06-PCT may function as ports or endpoints depending on the configuration and role within the system. An optical interface can refer to a physical or logical point where optical signals or channels are introduced and / or received through optical fibers or connectors. While the system is characterized as having two interfaces, any number of interfaces may also be used as optical inputs and / or outputs. Discussion of the first optical interface no and second optical interface 120 does not limit the system to only two distinct interfaces. Herein the first optical interface no is generally characterized as an input and the second optical interface 120 is generally characterized as an output. Though the input / output role of any interface can be set according to a corresponding application.

[0070] Accordingly, the first optical interface 110 may function as an optical source interface configured to introduce optical signals into the optical interconnect system 100, and the second optical interface 120 may function as an optical receiver interface configured to receive optical signals from the optical interconnect system 100, or vice versa. Each optical interface may include one or more optical channels 112, 122, where each optical channel represents an independent optical path for optical signal transmission.

[0071] The first optical interface 110 and / or the second optical interface 120 may include an array of optical channels arranged in a one-dimensional configuration, a two-dimensional configuration, or any suitable combination of channels. A one-dimensional array may include a linear arrangement of optical channels. A two-dimensional array may include a planar arrangement of optical channels for example. The array may include at least four optical channels. In one example, the array may include at least eight optical channels. Instead of an organized array of channels, there maybe any organization of a set of channels. As one example, multicore fiber may be used where multiple individual fibers correspond to an optical interface (e.g., 110) and each fiber includes multiple channels through the multiple cores within the multicore fiber.

[0072] The first optical interface 110 and / or the second optical interface 120 may include or otherwise interface with various types of optical fibers. The optical fibers may include singlemode fibers, multimode fibers, multicore fibers, polarization-maintaining fibers, hollow-core fibers, photonic crystal fibers, and / or other types of fiber or optical channels. The nanofabricated optical body 130 may be configured to interface with any of these fiber types, adapting beam parameters and alignment structures to match the mode characteristics of the respective fiber type.

[0073] As one variation, the number of channels of one optical interface may correspond one-to-one to the channels of another interface. However, in some variations, the number ofIRRA-M06-PCT channels may not be one-to-one where the optical structure can transform between interfaces with differing number of channels (e.g., reducing / merging or expanding / splitting number of channels).

[0074] The optical interfaces 110, 120 may apply across different coupling regimes used in photonic systems. The optical interfaces 110, 120 may include surface-coupled interfaces, edge-coupled interfaces, and / or surface-emitting interfaces. The optical interconnect system 100 may provide a common connector and coupling platform that adapts to how light is emitted, routed, or extracted across these coupling regimes.

[0075] In some surface-coupled variations, surface-coupled interfaces may include gratingbased interfaces and / or mirror-based interfaces as used in silicon photonics. Grating-based interfaces may use grating couplers to couple light between free-space optical fields and waveguide modes. Mirror-based interfaces may use 45-degree mirrors or other angled reflective surfaces to redirect light between surface-normal directions and in-plane directions. The nanofabricated optical body 130 may enable precise beam shaping and relaxed alignment tolerance for surface-coupled interfaces, facilitating scalable fiber-array attachment.

[0076] In some edge-coupled interfaces, edge-coupled interfaces may include direct coupling interfaces to waveguides, such as silicon waveguides of a photonic integrated circuit. The nanofabricated optical body 130 may enable expanded-beam routing and vertically integrated relay optics that provide optical clearance at the chip edge, decoupling optical input / output from electrical and thermal routing constraints along the chip shoreline.

[0077] In some surface-emitting interfaces, surface-emitting interfaces may include interfaces for vertical-cavity surface-emitting lasers (VCSELs), micro-LEDs, multicore optical fibers, and / or multimode optical fibers. In surface-emitting configurations, light may be shaped, redirected, and launched out of plane. The nanofabricated optical body 130 may enable perchannel adaptive alignment and beam expansion for uniform coupling across dense two-dimensional arrays of surface-emitting interfaces.

[0078] The optical interfaces are not limited to these types of interface couplings.

[0079] Such flexibility in interface coupling may be leveraged by a system to address many packaging challenges present in optical communication and / or computing applications. The optical interconnect system 100 may maintain optical alignment simultaneously across many channels at a fiber-array boundary using the nanofabricated optical body 130. The lithographically defined structures of the nanofabricated optical body 130 may embed alignment, beam shaping, and routing as passive optical functions at the interface.Lithographically patterned micro-optics may be integrated into the nanoporous scaffold 132 forIRRA-M06-PCT repeatable coupling at scale across all three coupling regimes. As shown in FIG. 14A, microlenses may be printed directly on top of fiber interfaces, with a visible scaffold around the printed structures. As shown in FIG. 14B, microlenses may be lithographically aligned to fiber cores, as verified by confocal imaging.

[0080] The optical interconnect system 100 may establish a common interconnect architecture that supports diverse geometries, channel densities, and routing requirements across the coupling regimes described herein. The optical interconnect system 100 may be compatible with wafer-level manufacturing processes and enable passive assembly techniques.

[0081] The optical interfaces (e.g., 110 / 120) engage with the nanofabricated optical body to facilitate a desired optical mapping between the optical interfaces. The optical mapping in one example can route between two optical interfaces functioning as a source interface or a receiver interface.

[0082] The optical mapping in some variations may be a mapping between an array of optical channels functioning as optical sources and an array of optical channels functioning as receivers. Herein, the mapping is primarily described as mapping between two arrays of optical channels. However, the mapping may also map between channels of more than two optical interfaces such as one source array to multiple receiver arrays, multiple source arrays to one receiver arrays, or multiple source arrays to multiple receiver arrays.

[0083] The optical channels 112, 122 represent independent optical paths that connect the first optical interface 110 to the second optical interface 120. The optical channels 112, 122 may be arranged in arrays at each optical interface. The nanofabricated optical body 130 may map optical channels 112 of the first optical interface 110 to optical channels 122 of the second optical interface 120.

[0084] The nanofabricated optical body 130 may enable arbitrary mapping between arrays of optical channels. In particular, the nanofabricated optical body 130 may map between a first array geometry of the first optical interface no and a second array geometry of the second optical interface 120 that differs from the first array geometry in pitch, orientation, and / or spatial arrangement. In one variation, the first array geometry may include a linear array, and the second array geometry may include a two-dimensional array. In another variation, the first array geometry may include a two-dimensional array, and the second array geometry may include a linear array. In yet another variation, the first array geometry and the second array geometry may have different pitch spacings. In still another variation, the first array geometry and the second array geometry may have different orientations, such as arrays rotated relative to one another. In yet another variation, the nanofabricated optical body 130 may reconfigureIRRA-M06-PCT spatial arrangements between arrays, such as mapping circular arrays to rectangular arrays. This may be used, for example, to map from multiple multicore fibers, where each fiber may have a radially arranged array of fiber cores (i.e., channels), to another interface.

[0085] The optical channels 112, 122 may interface with various optical elements including single-mode optical fibers, multimode optical fibers, vertical-cavity surface-emitting lasers (VCSELs), light-emitting diodes (LEDs), photodetectors, and / or waveguides. The photodetectors may include PIN diodes, avalanche photodiodes, single-photon avalanche diode (SPAD) arrays, and / or CMOS photodetectors. The waveguides may include planar waveguides and / or ridge waveguides.

[0086] In one variation, the first optical interface 110 and / or the second optical interface 120 may include a fiber array unit 140 or a fiber connector. The fiber array unit 140 may include an array of optical fibers arranged in a one-dimensional configuration or a two-dimensional configuration. The fiber array unit 140 may include a fiber connector 144 such as a multi-fiber termination push-on (MTP) connector or a multi-fiber push-on (MPO) connector. The fiber array unit 140 may include single-mode optical fibers (e.g., SMF-28), multimode optical fibers, and / or multicore optical fibers. The fiber array unit 140 may include four, eight, twelve, sixteen, twenty-four, or more optical fibers.

[0087] The nanofabricated optical body 130 may be fabricated directly on or adjacent to the fiber array unit 140. As shown in FIG. 16A, lithographically patterned microlenses and beamshaping elements may be printed directly on a fiber array to enable expanded-beam routing at the optical interface. As shown in FIG. 16B, confocal imaging may verify that microlenses are lithographically aligned to individual fiber cores, demonstrating precise beam expansion and spatial registration. The nanofabricated optical body 130 may be lithographically aligned to fiber cores of the fiber array unit 140, enabling optical alignment to be maintained across multiple channels simultaneously. This lithographic alignment may enable passive fiber-array attachment without active optical alignment during assembly. In some variations, the nanofabricated optical body 130 may include microlenses printed directly on top of fiber endfaces of the fiber array unit 140.

[0088] In another variation, the first optical interface 110 and / or the second optical interface 120 may include a multicore optical fiber 142. The multicore optical fiber 142 may include a plurality of cores arranged in a two-dimensional configuration within a single fiber cladding. The multicore optical fiber 142 may include two or more cores. Common examples may include four, seven, eight, twelve, nineteen, or more cores. The nanofabricated optical body 130 maybe configured to spatially separate optical channels from cores of the multicore optical fiber 142 orIRRA-M06-PCT to spatially combine optical channels into cores of the multicore optical fiber 142, thereby providing fan-in or fan-out functionality.

[0089] As shown in FIG. 18, in multicore and multimode fiber configurations, light may be launched out of plane from dense two-dimensional arrays of cores or mode regions. The nanofabricated optical body 130 may treat such surface-emitting fiber interfaces as two-dimensional optical arrays that can be corrected and routed on a per-channel basis with lithographically defined adaptive alignment and beam expansion applied on a per-channel basis. Lithographically defined optical elements may be patterned directly at the interface to control beam position, angle, and expansion for each individual core or mode, enabling uniform and repeatable coupling across the entire array. Beams emerging from multi core or multimode fibers maybe expanded and shaped at the interface, reducing sensitivity to small placement errors and increasing tolerance to angular misalignment. Per-channel adaptive alignment structures may steer each expanded beam toward a common optical axis or target aperture, compensating for intrinsic offsets between cores as well as assembly-level variations.

[0090] By expanding and correcting beams at the surface-emitting interface, optical complexity may be absorbed into the lithographically defined micro-optics rather than being managed through mechanical alignment. This may enable dense fiber arrays to be attached passively while achieving consistent beam placement and mode quality across channels.Expanded beams from multicore or multimode fibers may be mapped, re-ordered, or routed into free-space or guided optical structures without requiring tight one-to-one correspondence between individual cores and target waveguides.

[0091] The fiber connector 144 may include a multi-fiber termination push-on (MTP) connector or a multi-fiber push-on (MPO) connector as shown in FIG. 3. The fiber connector 144 may provide a standardized interface for connecting the fiber array unit 140 to external optical systems. The fiber connector 144 may support single-row or multi-row fiber configurations. In some variations, the fiber connector 144 may be a high-density fiber optic connector configured for data center, telecommunications, and / or high-performance computing applications.

[0092] As shown in FIG. 3, the optical interconnect system 100 may connect a fiber connector 144 such as an MTP or MPO connector to an array of edge couplers 146 on a photonic integrated circuit, with the nanofabricated optical body 130 facilitating array-to-array routing between the fiber array and the edge coupler array. As shown in FIG. 6, various output parameters may be configured for edge coupling into a photonic integrated circuit. In another variation, the second optical interface 120 (or any suitable interface such as 110) may include anIRRA-M06-PCT edge coupler 146 of a photonic integrated circuit. The edge coupler 146 may enable direct coupling into on-chip waveguides of the photonic integrated circuit. Edge coupling may provide low-loss, broadband coupling directly into waveguides of the photonic integrated circuit.

[0093] The nanofabricated optical body 130 may be configured to focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler 146. The nanofabricated optical body 130 may transform the spatially expanded optical field into a focused optical field having a spot size matched to an input mode (or output) of the edge coupler 146.

[0094] In one variation, the nanofabricated optical body 130 may be configured to route the optical field through an angular redirection for directing the optical field to a lateral facet of the photonic integrated circuit. The nanofabricated optical body 130 may route the optical field vertically away from an edge of the photonic integrated circuit before directing the optical field to the edge coupler 146. This vertical routing may accommodate mechanical fixtures, wire bonds, electrical routing, thermal management components, and / or other components that occupy space near the chip edge while still enabling efficient optical coupling to the edge coupler 146. Optical beams may be expanded and shaped at the fiber-array interface and then redirected using lithographically defined micro-optics of the nanofabricated optical body 130.

[0095] As shown in FIG. 17A, in one exemplary variation, a two-lens relay architecture may be employed to lift the optical path vertically away from the chip edge. A first lens may expand and collimate an optical beam emerging from the first optical interface 110, while a second lens may refocus or redirect the expanded beam toward the edge coupler 146. As shown in FIG. 17B, the vertical optical clearance at the chip edge may enable simultaneous optical coupling and electrical and thermal routing. As shown in FIG. 17C, comparison between optical simulation and experimental prototype results may demonstrate agreement in beam propagation through the expanded-beam relay structure. By distributing beam bending across multiple optical surfaces, this approach may enable large angular redirection within a compact volume while preserving beam quality and reducing sensitivity to small placement errors. Because the relay optics may be lithographically patterned and registered to fiber cores, the vertical routing geometry may be defined at design time without requiring mechanical tuning during assembly. This may enable fiber arrays to be attached with passive alignment while achieving expanded-beam vertical routing with relaxed alignment tolerances.

[0096] A configured optical structure of the system may be used to enable an edge-coupled clearance architecture, which may provide vertical optical clearance at the chip edge, enabling simultaneous optical coupling and electrical and / or thermal routing along the chip shoreline. InIRRA-M06-PCT this vertically offset edge-coupled interface variation, interfaces may be substantially parallel at the interface but with the optical structure routing optical signals vertically to offset the alignment of the interfaces. The limited chip shoreline of a photonic integrated circuit may need to simultaneously accommodate optical input / output, electrical routing, thermal management, and mechanical fixtures. The vertical routing provided by the nanofabricated optical body 130 may decouple the optical interface from these other shoreline constraints.

[0097] In operation, the edge-coupled clearance architecture may function in one example as follows. Optical beams from the first optical interface 110 (e.g., a fiber array) may first be expanded and shaped by a first lens of a two-lens relay. The expanded beams may then propagate through a free-space region where the beam diameter is increased, reducing sensitivity to positional and angular errors. The second lens may then redirect and focus the expanded beams toward the lateral facet of the photonic integrated circuit where the edge coupler 146 is located. The angular redirection may include a 90-degree turn or other large-angle redirection to route the optical path from a vertical orientation (away from the chip surface) to a horizontal orientation (toward the chip edge).

[0098] The two-lens relay architecture may achieve efficient coupling with relaxed alignment tolerances. The expanded-beam region between the two lenses may provide tolerance to small placement errors during assembly. The lithographically defined geometry of the relay optics may ensure repeatable beam propagation through the relay structure across multiple fabricated devices. Other optical structures as described herein may additionally or alternatively be used to achieve similar edge-coupled vertical offsets.

[0099] In another variation, the second optical interface 120 (or any suitable optical interface such as 110) may include a surface-normal interface 148 of a photonic integrated circuit. The surface-normal interface 148 may include a grating-based interface and / or a mirrorbased interface. A grating-based interface may include a grating coupler configured to couple light between the spatially expanded optical field and a waveguide mode of the photonic integrated circuit. The grating coupler may diffract light from a surface-normal direction into an in-plane waveguide mode, or vice versa. A mirror-based interface in one variation may include a 45-degree mirror or other angled reflective surface configured to redirect light between a surface-normal direction and an in-plane direction.

[0100] The nanofabricated optical body 130 may enable precise beam shaping and relaxed alignment tolerance for surface-coupled interfaces. Lithographically defined micro-optics may be integrated with the surface-normal interface 148 to facilitate scalable fiber-array attachment. The nanofabricated optical body 130 may shape the spatially expanded optical field to match anIRRA-M06-PCT acceptance angle and spot size of the grating coupler or mirror-based interface. In some variations, the nanofabricated optical body 130 may be fabricated directly on top of the surfacenormal interface 148 of the photonic integrated circuit.

[0101] In another variation, the first optical interface 110 or the second optical interface 120 may comprise a vertical-cavity surface-emitting laser (VCSEL), a light-emitting diode (LED), a photodetector, and / or any suitable optical emitter or receiver. In some variations, the first optical interface 110 and / or the second optical interface 120 may include an active optical device array 150 comprising one or more VCSELs, one or more LEDs, one or more micro-LEDs, and / or one or more photodetectors. Multiple instances of the optical interconnect system 100 maybe used to connect emitter arrays to detector arrays using optical interconnects and multichannel fiber links. The active optical device arrays may be arranged in various configurations including linear arrays, rectangular arrays, hexagonal arrays, or other two-dimensional arrangements suited to the application. The photodetectors may include PIN photodiodes, avalanche photodiodes, single-photon avalanche diodes (SPADs), and / or other photodetector types. In such surface-emitting configurations, light may be shaped, redirected, and launched out of plane from the active optical device array 150.

[0102] The nanofabricated optical body 130 may enable per-channel adaptive alignment and beam expansion for uniform coupling across dense two-dimensional arrays of active optical devices. Lithographically defined optical elements may control beam position, angle, and expansion for each individual emitter or detector, enabling consistent coupling across the active optical device array 150. For VCSEL arrays, the nanofabricated optical body 130 may collimate and redirect emitted beams toward the second optical interface 120. For photodetector arrays, the nanofabricated optical body 130 may focus and direct incoming optical signals onto active regions of the photodetectors.

[0103] These routing implementations are presented as alternative embodiments of a common design philosophy: optical complexity is absorbed into lithographically defined, monolithic structures rather than managed through mechanically positioned bulk optics or postassembly tuning. Several complementary approaches are described below.

[0104] The nanofabricated optical body 130 may be formed using a 3D nanofabrication process that enables the creation of arbitrary three-dimensional geometries with gradients of refractive index contrast. The 3D nanofabrication process may deposit materials within a nanoporous scaffold 132 to form optical structures 134. The nanofabricated optical body 130 may include beam-shaping elements, beam-steering elements, alignment correction elements, and / or optical routing elements integrated within a single monolithic structure. More generally,IRRA-M06-PCT the nanofabricated optical body 130 may be referred to as an optical body, which may include features at greater than nanoscale dimensions in some variations.

[0105] The nanofabricated optical body 130 may employ lithographic techniques for patterning of fill materials within the nanoporous scaffold 132. The lithographic process may use various mechanisms including one-photon or two-photon initiation of polymerization, multiphoton absorption, attachment of molecules to the scaffold with reactive groups for later bulk material deposition, and / or multi-step chemical reactions.

[0106] Various optical structures 134 may be formed within the nanofabricated optical body 130. In one variation, microlenses and micro-prisms may be patterned directly onto fiber arrays or coupling scaffolds using the 3D nanofabrication process, allowing optical beams to be expanded, shaped, and redirected immediately upon exiting the first optical interface 110.Because these elements maybe lithographically registered to underlying fiber cores or photonic features, expanded-beam routing may be achieved with high spatial precision and repeatability without reliance on bulk optics or mechanically positioned components.

[0107] The nanofabricated optical body 130 may include a three-dimensional nanoporous scaffold 132. The nanoporous scaffold 132 may comprise an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material. The aerogel may include silica aerogel, polymer aerogel, and / or metal chalcogenide aerogel. The polymeric scaffold may include polymer gels and / or other polymeric porous materials. The porous glass may include porous silica glass and / or other porous glass materials. The porosified semiconductor material may include porosified silicon, porosified germanium, and / or other porosified semiconductor materials.

[0108] The nanoporous scaffold 132 may provide a three-dimensional matrix within which the optical structures 134 maybe formed. The porosity of the nanoporous scaffold 132 may enable deposition of fill materials throughout the three-dimensional volume, allowing the creation of arbitrary three-dimensional optical geometries. The nanoporous scaffold 132 may have a refractive index that differs from the deposited fill materials, enabling refractive index contrast between filled and unfilled regions.

[0109] The optical structures 134 may be formed by depositing materials within the nanoporous scaffold 132. The optical structures 134 may be formed by two-photon polymerization or multiphoton absorption within the nanoporous scaffold 132. The deposited materials may comprise polymers, metal chalcogenides, semiconductors, or metals. The metal chalcogenides may include zinc sulfide (ZnS), lead sulfide (PbS), cadmium sulfide (CdS), and / orIRRA-M06-PCT other metal chalcogenides. The semiconductors may include silicon, germanium, and / or other semiconductor materials. The metals may include silver, gold, copper, and / or other metals.

[0110] The fill materials may be selected based on desired optical properties of the optical structures 134. Different fill materials may provide different refractive indices, enabling the creation of gradient-index optical regions within the nanofabricated optical body 130. The optical structures 134 may form functional optical elements including lenses, prisms, waveguides, gradient-index regions, reflective surfaces, and / or diffractive elements.

[0111] As a variation of optical structures 134, the system may include formed mechanical structures, which may functionally support mechanical or alignment capabilities instead of or in addition to optical functionality. Accordingly, the nanofabrication platform may also form mechanical structures in addition to optical structures. The same lithographic process used to create optical elements may be used to create physical alignment features, registration structures, or mechanical coupling interfaces within the nanofabricated optical body 130. These mechanical structures may be formed concurrently with optical structures and may facilitate mechanical positioning during assembly of optical interfaces. In some alternatives, the system may include external mechanical structures or attachment fixture components that are added to or interface with the optical body 130.

[0112] The nanofabricated optical body 130 may be lithographically aligned to the first optical interface 110. The nanofabricated optical body 130 may achieve sub-micron alignment precision relative to the first optical interface 110. The nanofabricated optical body 130 maybe lithographically aligned to a fiber core of the first optical interface no.

[0113] The nanofabricated optical body 130 may include optical correction structures that adjust beam position, beam angle, or optical phase. The optical correction structures maybe configured to compensate for positional or angular variation of optical channels. Each channel in a multi-channel array may receive a tailored optical correction that brings all outputs to a common deflection angle. Relative geometry and rotation of the optical structures 134 may compensate for placement and fabrication variations, steering beams toward a desired principal axis without active tuning.

[0114] The optical interconnect system too may include alignment features facilitating optical alignment of the optical structures 134 during the lithographic process of nanofabrication. The alignment features may include fiducial markers integrated into the substrate or the nanoporous scaffold 132. An imaging system may detect and track the alignment features during fabrication. The imaging system may image the underlying substrate using optical microscopy, fluorescence microscopy, or by imaging light emitted from the firstIRRA-M06-PCT optical interface no (e.g., light emitted by an optical fiber or LED). This lithographic alignment may embed alignment functionality into the fabrication process, transforming optical alignment from a manual assembly operation into a manufacturable process.

[0115] The alignment features may serve fabrication purposes (for positional adjustments during nanofabrication) and / or assembly purposes (for mechanical registration during attachment of optical interfaces). In some variations, alignment features formed during nanofabrication may provide physical registration surfaces for subsequent mechanical positioning of optical components. The same lithographic capability that enables precise optical alignment during fabrication may also enable the creation of mechanical alignment structures that facilitate passive mechanical attachment of the second optical interface 120. Mechanical structures functioning as alignment features maybe used for any suitable optical interface (e.g., 110 or 120).

[0116] As shown in FIG. 5, the nanofabricated optical body 130 may include gradient-index (GRIN) optical regions 160. The gradient-index optical regions 160 may comprise GRIN lenses or GRIN Fresnel lenses that direct light at an angle and then straighten it for proper coupling. The gradient-index optical regions 160 may have a refractive index that varies continuously within the routing volume rather than relying on discrete refractive surfaces.

[0117] As shown in FIG. 20A and FIG. 20B, the continuous refractive index variation of the gradient-index optical regions 160 may enable smooth beam bending without discrete optical surfaces. This smooth bending may allow compact routing with reduced aberrations and controlled mode evolution compared to multi-surface refractive approaches. Lithographically defined GRIN regions may guide expanded beams through curved trajectories, enabling large-angle deflection and compact routing while preserving beam uniformity across channels.

[0118] The gradient-index optical regions 160 may be formed by spatially varying the deposition of fill materials within the nanoporous scaffold 132. By controlling the local concentration or composition of deposited materials, a gradient in refractive index may be established across the optical region. The 3D nanofabrication process may enable arbitrary GRIN profiles to be defined, including radial gradients, axial gradients, and / or more complex three-dimensional index distributions.

[0119] In one variation, the gradient-index optical regions 160 may include GRIN lenses configured for beam collimation, focusing, or mode transformation. In another variation, the gradient-index optical regions 160 may include GRIN Fresnel lenses that combine gradientindex behavior with Fresnel zone structures for reduced thickness. In yet another variation, theIRRA-M06-PCT gradient-index optical regions 160 may be configured for optical routing, bending optical beams through curved paths defined by the refractive index gradient.

[0120] The gradient-index optical regions 160 may be particularly useful for dense arrays where space constraints limit the use of multi-surface refractive optics. The smooth beam trajectories achievable with GRIN structures may enable optical routing within compact volumes while maintaining beam quality and uniformity across multiple channels.

[0121] The nanofabricated optical body 130 may include one or more refractive optical surfaces 162. As shown in FIG. 7 and FIG. 8, the refractive optical surfaces 162 may comprise aspheric lenses and prisms configured to tilt and then straighten collimated light. As shown in FIG. 9, the refractive optical surfaces 162 may alternatively comprise plano-convex lenses. The refractive optical surfaces 162 may comprise aspheric lenses, freeform lenses, microlenses, prisms, and / or other refractive elements. The refractive optical surfaces 162 maybe used for collimation, expansion, and transformation of optical beams. The refractive optical surfaces 162 may adjust mode shape, geometiy, and position to enhance coupling efficiency with an array of receivers.

[0122] In one variation, the refractive optical surfaces 162 may include microlenses patterned directly onto or at least relative to fiber arrays or coupling scaffolds. The microlenses may expand and shape optical beams immediately upon exiting the first optical interface 110. In another variation, the refractive optical surfaces 162 may include aspheric lenses or freeform lenses configured to correct for optical aberrations and / or to transform beam geometry.Aspheric and freeform lens surfaces may enable more complex beam shaping than spherical surfaces while maintaining compact form factors.

[0123] In another variation, the refractive optical surfaces 162 may include prisms configured for beam steering and / or angular redirection. Micro-prisms may redirect optical beams through controlled angles without requiring curved surfaces. Prisms maybe combined with lenses to provide both beam shaping and beam steering within a single optical path.

[0124] As shown in FIG. 19A and FIG. 19B, in yet another variation, the nanofabricated optical body 130 may include cascaded refractive optical surfaces for refractive free-space optical routing. By distributing beam bending across multiple refractive interfaces, large angular redirection may be achieved within a compact footprint while maintaining beam quality and relaxed alignment sensitivity. This approach may be well-suited for applications where beams must be routed around physical obstructions or redirected into non-collinear planes. Because the refractive elements may be lithographically registered to the source array, beam trajectories may be defined at design time and remain stable during assembly.IRRA-M06-PCT

[0125] The refractive optical surfaces 162 may be formed by patterning fill materials within the nanoporous scaffold 132 to create regions of higher refractive index. The interface between filled and unfilled regions, or between regions with different fill materials, may form the refractive surfaces that bend and shape optical beams.

[0126] The refractive optical surfaces 162 may be lithographically aligned to one or both optical interfaces. In one variation, the refractive optical surfaces 162 may be disposed at the first optical interface no and configured to condition and redirect an expanded collimated beam toward the second optical interface 120. In this single-sided configuration, the refractive optical surfaces 162 may expand, shape, and steer the optical beam from the first optical interface 110, with the expanded beam propagating directly to the second optical interface 120.

[0127] In another variation, the refractive optical surfaces 162 may be disposed at both the first optical interface 110 and the second optical interface 120. In this double-sided configuration, a first set of refractive optical surfaces may condition and expand optical beams from the first optical interface no, an expanded collimated beam may propagate through a free-space region between the interfaces, and a second set of refractive optical surfaces may receive and focus the expanded beam into the second optical interface 120. The expanded collimated beam region between the two sets of conditioning optics may provide relaxed alignment tolerance during assembly.

[0128] The nanofabricated optical body 130 may include one or more reflective surfaces 164. The reflective surfaces 164 may be configured for total internal reflection (TIR) and / or mirrorbased reflection. Reflective surfaces may provide efficient beam redirection, particularly for large-angle turns where refractive approaches would require multiple surfaces or introduce significant aberrations.

[0129] As shown in FIG. 21, in one variation, the nanofabricated optical body 130 may include integrated TIR prism structures for large-angle beam redirection with minimal optical loss. The TIR prism structures may use total internal reflection at prism facets to redirect optical beams. Total internal reflection may occur when light traveling within a higher-index medium strikes an interface with a lower-index medium at an angle greater than the critical angle. TIR-based routing may provide efficient beam turning with minimal absorption or scattering losses.

[0130] The TIR prism structures may be fabricated directly as part of the nanoporous scaffold 132 or maybe integrated as bonded components aligned to the expanded-beam interface. In one variation, expanded beams maybe redirected via total internal reflection within monolithically integrated prism structures. The prism facets may be oriented to achieve 45-degree, 90-degree, or other angular redirections as required by the optical path geometry.IRRA-M06-PCT

[0131] In another variation, the reflective surfaces 164 may include mirror surfaces formed by depositing metallic fill materials within the nanoporous scaffold 132. The metallic surfaces may provide specular reflection for beam redirection. Mirror-based reflection may be used where TIR geometry is not achievable or where broadband reflection is required.

[0132] The reflective surfaces 164 may be combined with refractive optical surfaces 162 to form hybrid optical paths. For example, a lens may expand and collimate a beam, a TIR prism may redirect the expanded beam through a 90-degree turn, and a second lens may focus the redirected beam toward the second optical interface 120.

[0133] The nanofabricated optical body 130 may include waveguiding regions 166. The waveguiding regions 166 may confine and guide optical signals within higher-index core regions surrounded by lower-index cladding regions. The waveguiding regions 166 may be formed by patterning fill materials within the nanoporous scaffold 132 to create index-contrast structures that support guided optical modes.

[0134] In one variation, the waveguiding regions 166 may be configured for fan-in or fan-out routing of a plurality of optical channels. In fan-out configurations, the waveguiding regions 166 may receive optical signals from a dense array (e.g., a multi core fiber 142) and spatially separate the signals to a larger pitch spacing suitable for the second optical interface 120. In fan-in configurations, the waveguiding regions 166 may receive optical signals at a larger pitch spacing and route them into a denser array configuration.

[0135] As shown in FIG. 22, in waveguide-based routing, expanded beams may be coupled into guided modes at input coupling structures, routed within the nanofabricated optical body 130 along defined waveguide paths, and re-emitted at output coupling structures toward the target interface. The input and output coupling structures may include tapered regions, grating couplers, or other mode-matching elements that transition between free-space beams and guided modes.

[0136] The waveguiding regions 166 may enable precise mapping between dense arrays with differing pitch and / or geometry. Because the waveguide paths are lithographically defined, arbitrary routing patterns may be implemented including crossings, bends, and three-dimensional trajectories. The waveguiding regions 166 may be particularly useful for applications requiring complex channel rearrangement or where the first optical interface 110 and the second optical interface 120 have incompatible array geometries.

[0137] The waveguiding regions 166 may be combined with other optical element types. For example, refractive optical surfaces 162 may expand and collimate beams from the first optical interface 110, the waveguiding regions 166 may route the beams through fan-out orIRRA-M06-PCT rearrangement paths, and additional refractive optical surfaces 162 may focus the beams into the second optical interface 120.

[0138] As shown in FIG. 23, the nanofabricated optical body 130 may include diffractive optical elements 168. The diffractive optical elements 168 may use periodic or aperiodic structures to manipulate optical wavefronts through diffraction. The diffractive optical elements 168 may comprise gratings, diffractive lenses, or holograms.

[0139] In one variation, the diffractive optical elements 168 may include gratings configured for beam deflection, wavelength separation, or coupling between free-space beams and guided modes. In another variation, the diffractive optical elements 168 may include diffractive lenses that achieve focusing or beam shaping through phase manipulation rather than refractive index gradients. In yet another variation, the diffractive optical elements 168 may include holograms configured for complex wavefront transformation or beam splitting.

[0140] The nanofabricated optical body 130 may include metasurface optical elements or three-dimensional meta-volume optical elements. Metasurface optical elements may include sub-wavelength structures arranged to impart spatially varying phase, amplitude, or polarization to transmitted or reflected light. Meta-volume optical elements may extend this concept into three dimensions, with multi-layered meta-optics enabling more complex optical transformations. The 3D nanofabrication process may enable fabrication of both metasurface and meta-volume structures within the nanoporous scaffold 132.

[0141] The nanofabricated optical body 130 may include wavelength-selective optical structures. The wavelength-selective optical structures may comprise dispersive elements or grating structures. The wavelength-selective optical structures may enable wavelength-based multiplexing or demultiplexing of optical signals.

[0142] The nanofabricated optical body 130 may include polarization-selective optical structures. The polarization-selective optical structures may comprise polarization-splitting structures. The polarization-selective optical structures may enable polarization-based multiplexing or demultiplexing of optical signals.

[0143] The nanofabricated optical body 130 may include mode-selective optical structures. The mode-selective optical structures may enable spatial-based or mode-based multiplexing or demultiplexing of optical signals.

[0144] The nanofabricated optical body 130 may include beam-splitting or beam-combining optical elements. The beam-splitting or beam-combining optical elements may include lens arrays, prisms, and / or dichroic mirrors.IRRA-M06-PCT

[0145] The nanofabricated optical body 130 may be configured to route the optical field through an optical path with angular redirection. The angular redirection may range from small angles (e.g., slight beam steering for alignment correction) to large angles up to and including 180 degrees (e.g., a fold-back configuration). In one variation, the angular redirection maybe at least 45 degrees. In another variation, the angular redirection may comprise a 90-degree turn. In yet another variation, the angular redirection may comprise a 180-degree turn.

[0146] Non-collinear routing may be achieved using refractive free-space routing with cascaded optical surfaces, gradient-index structures, TIR prism architectures, and / or waveguide-based routing. The non-collinear routing implementations may enable optical beams to be redirected through various angles, routed around physical constraints, or re-distributed within compact volumes while preserving beam quality.

[0147] The second optical interface 120 may be mechanically positioned relative to the nanofabricated optical body 130 without active optical alignment.

[0148] Active optical alignment may be characterized as positioning that uses real-time optical feedback, such as measured coupling efficiency or optical signal strength, to iteratively adjust component position during assembly. Mechanical positioning without active optical alignment includes positioning based on mechanical references such as kinematic mounts (e.g., Maxwell coupling, Kelvin coupling), mechanical registration features, fixtures, or vision-based alignment to mechanical fiducials, without requiring real-time optical feedback to optimize coupling.

[0149] Mechanical positioning may include bonding using an adhesive, a thermal cure, an ultraviolet cure, a solder bond, glass frit bond, or other bonding or fixturing approach. The expanded-beam architecture of the nanofabricated optical body 130 may enable passive alignment of the second optical interface 120 without sacrificing coupling efficiency. By embedding alignment into the lithographic fabrication process, the nanofabricated optical body 130 may enable repeatable and scalable fiber-array attachment without post-assembly optical tuning.

[0150] In some variations, the nanofabricated optical body 130 may include mechanical alignment structures in addition to optical structures. The mechanical alignment structures may be nanofabricated concurrently with the optical structures using the same lithographic process. The mechanical alignment structures may include alignment features such as alignment posts, sockets, grooves, mating surfaces, and / or other physical features configured to engage with corresponding features on the first and / or second optical interface 110 / 120 and / or on an external fixture. The mechanical alignment structures may provide coarse positioning to bringIRRA-M06-PCT the second optical interface 120 within the alignment tolerance enabled by the expanded-beam architecture, thereby facilitating passive mechanical attachment. In some variations, the mechanical alignment structures may be configured to engage with standardized connector interfaces. In some variations, these mechanical alignment structures may be kinematic alignment structures such as Maxwell or Kevlin coupling.

[0151] In some variations, the mechanical alignment structures may implement elastic averaging, where multiple compliant contact points collectively determine position. Elastic averaging may provide positioning that is less sensitive to manufacturing tolerances or contamination compared to exact-constraint kinematic coupling. Other precision engineering component features may alternatively be used.

[0152] As described herein, the optical interconnect system 100 may be configured for passive mechanical attachment, where passive mechanical attachment refers to mechanical positioning without active optical alignment. The second optical interface 120 or any suitable optical interface (e.g., no) maybe a passive mechanical attachment interface, meaning the second optical interface 120 itself is configured for passive mechanical attachment. The passive mechanical attachment interface may include the mechanical alignment structures described above.

[0153] In various implementations, a passive mechanical attachment may be realized in different configurations. In one variation, the second optical interface 120 may be the passive mechanical attachment interface, where the interface itself incorporates mechanical alignment structures. In another variation, a discrete passive mechanical attachment component may engage with the second optical interface 120 to facilitate positioning. In yet another variation, a passive mechanical attachment component may be attached to or integrated with the second optical interface 120. These variations may be used individually or in combination. In such variations, part or all of the mechanical structures included in a passive mechanical attachment interface maybe nanofabricated structures.

[0154] When the mechanical alignment structures are nanofabricated structures formed within the three-dimensional nanoporous scaffold 132, precise registration between optical and mechanical features may be achieved, as both are defined relative to the same fabrication coordinate system. The mechanical alignment structures may be fabricated from the scaffold material itself, patterned into the scaffold by depositing fill materials, and / or patterned out of the scaffold by selective removal or modification of scaffold material. In some variations, the mechanical alignment structures may be formed within the three-dimensional nanoporous scaffold 132 using the same lithographic techniques used to form the optical structures 134.IRRA-M06-PCT

[0155] Alternatively or additionally, the mechanical alignment structures may include externally fabricated structures. The externally fabricated structures maybe machined, molded, or otherwise formed separately from the nanofabrication process. The externally fabricated structures may be attached to or integrated with the nanofabricated optical body 130, the first optical interface 110, the second optical interface 120, and / or an external fixture.

[0156] In some variations, the mechanical alignment structures may be present on either or both sides of an interface. For example, mating mechanical alignment structures may be formed on both the nanofabricated optical body 130 and the second optical interface 120. In some variations, the mechanical alignment structures on one or both sides maybe nanofabricated, while in other variations one side may include externally fabricated structures.3. Method

[0157] As shown in FIG. 26 FIG. 27, a method for producing an optical interconnect may include providing a first optical interface S110, determining a spatial position of an optical feature associated with the first optical interface S120, registering a fabrication coordinate system to the determined spatial position S130, and nanofabricating at least one optical structure relative to the first optical interface S140. Optionally, the method may further include performing calibration S150 and mechanically attaching a second optical interface S160. The nanofabricated optical body may be configured to transform an optical field associated with the first optical interface into a spatially expanded optical field and to direct the spatially expanded optical field toward a second optical interface.

[0158] In one variation, nanofabricating (S140) may include depositing materials within a three-dimensional nanoporous scaffold. The nanoporous scaffold may comprise an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material. The deposited materials may comprise polymers, metal chalcogenides, semiconductors, or metals. The nanofabrication process may use volumetric lithographic writing of optical material. The volumetric lithographic writing may comprise two-photon polymerization or multiphoton absorption. The lithographic process may enable the creation of arbitrary three-dimensional geometries with tailored gradients in refractive index contrast.

[0159] In another variation, nanofabricating (S140) may include forming an expansion region that expands a guided optical mode into an expanded optical beam and forming a compression region that focuses the expanded optical beam toward the second optical interface. The expansion region and the compression region may form a relay that maps a first localizedIRRA-M06-PCT optical mode to a second localized optical mode through the spatially expanded optical field. The expanded optical beam may have a transverse diameter of at least too micrometers.

[0160] In yet another variation, the method may include lithographically aligning the optical structures to the first optical interface (S120, S130). The lithographic alignment may embed optical correction into the fabrication process, enabling the first optical interface to have adapted alignment and optical conditioning such that coupling at the second optical interface may accommodate less precise alignment. By embedding alignment into the lithographic process, the method may enable passive mechanical attachment of the second optical interface without active optical alignment (S160).

[0161] In yet another variation, determining the spatial position (S120) and registering the fabrication coordinate system (S130) may be performed independently for each of a plurality of optical channels of an arrayed first optical interface. The method may include computing perchannel optical correction parameters based on measured positional offsets of the plurality of optical channels. This per-channel adaptive correction may enable channel-specific optical correction structures to be formed for each channel of the arrayed interface.

[0162] Optionally, in some variations, the method may further include performing a calibration step S150 in which an emitted optical field is measured and a lithographic pattern is adjusted based on the measurement. The method may, in some variations, also include mechanically positioning the second optical interface relative to the nanofabricated optical body without active optical alignment S160. Mechanically positioning (S160) may comprise bonding using an adhesive, a thermal cure, an ultraviolet cure, a solder bond, or otherwise fixing position of the nanofabricated optical body and components / channels of an interface.

[0163] The method is primarily described as fabricating relative to a first interface, where the second interface may selectably engaged with an optical system or rigidly engaged. However, the processes described herein may be applied to any interface and / or channel of an interface across any suitable sets of interfaces and / or channels. Also, any channel or interface may have some portions more statically engaged where fabrication is done relative to them during production.

[0164] The method may be used in producing a system such as the one described herein. Furthermore, the method may include processes for producing any of the features of the system variation described herein. However, the method may also be adapted to producing alternative systems or systems directed to other applications.

[0165] Block S110, which includes providing a first optical interface, functions to establish optical channels at which optical signals enter or exit the optical interconnect system. The firstIRRA-M06-PCT optical interface may operate as an input interface, an output interface, or both an input and output interface depending on the application.

[0166] The first optical interface may comprise a fiber array unit, a multicore optical fiber, a fiber connector (e.g., a multi-fiber push-on connector or multi-fiber termination push-on connector), an edge coupler of a photonic integrated circuit, a surface-normal interface of a photonic integrated circuit, and / or an active optical device array (e.g., vertical-cavity surfaceemitting lasers, light-emitting diodes, or photodetectors). The first optical interface may include a one-dimensional or two-dimensional array of optical channels. Similarly, the first optical interface and / or any other optical interface may have any suitable arrangement of a plurality of optical channels. An optical interface may also be a single optical channel.

[0167] In some variations, the first optical interface may also include a coupling interface that is configured for engaging with another optical system subsequent to produce the optical body. In this variation, the first optical interface may include any suitable connector, fixture, or other coupling system that may be used to facilitate engagement with an external optical system.

[0168] The first optical interface may be mechanically positioned using bonding (e.g., an adhesive, a thermal cure, an ultraviolet cure, or a solder bond) or connector-based approaches. This may be used to rigidly connect an optical interface to a scaffold material of the optical body, in which optical structures will be produced subsequent to attaching. In some variations, the first optical interface may be rigidly fixed in place, with the nanofabricated optical body fabricated relative to the fixed first interface. This may enable the optical interconnect to facilitate more passive and less precise alignment with a second interface.

[0169] Block S120, which includes determining a spatial position of an optical feature associated with the first optical interface, functions to establish where optical channels are located prior to nanofabrication. Determining the spatial position may achieve sub-micron precision.

[0170] Determining the spatial position may be performed subsequent to an optical interface being in a state for alignment. In some variations, this may include determining the spatial position subsequent to an optical system like optical fiber being fixed in position to the first interface.

[0171] In one variation, determining the spatial position may include imaging a fiber core at a fiber endface of the first optical interface. Imaging the fiber core may comprise optical microscopy, fluorescence microscopy, confocal microscopy, and / or any suitable imaging process.IRRA-M06-PCT

[0172] In another variation, determining the spatial position may include imaging fiducial features associated with the first optical interface. The fiducial features maybe integrated into a substrate or scaffold material and may serve as reference markers for positional determination. Fiducial features may additionally or alternatively be integrated into an optical interface and / or an optical system(s) engaged or otherwise integrated with the optical interface.

[0173] In yet another variation, determining the spatial position may include imaging light emitted from the first optical interface to determine a mode center, mode profile, or pointing angle. This approach may enable characterization of optical qualities at the first optical interface, such as how fibers are terminated or the quality of fiber endfaces. This may include sensing or otherwise collecting optical signal values emitted out of the optical interface.

[0174] In yet another variation, determining the spatial position may include mechanically moving the optical feature into a fixture that restricts or promotes a particular spatial position. This mechanical approach may be used alone or in combination with imaging -based approaches.

[0175] For arrayed first optical interfaces, determining the spatial position may be performed independently for each of a plurality of optical channels. This per-channel determination may enable detection of channel-to-channel variations in position, angle, or optical quality.

[0176] In some variations, determining the spatial position may include automated processing of image data or sensor data. For example, determining the spatial position may include processing an image of the optical interface using a computer vision model, thereby determining the spatial position from the image data. Alternatively or additionally, determining the spatial position may include processing sensor data (e.g., optical power measurements, spectral data, or positional sensor readings) using an algorithm or model to extract spatial position information.

[0177] Block S130, which includes registering a fabrication coordinate system to the determined spatial position, functions to align the nanofabrication process to the actual location of optical features at the first optical interface. As shown in FIG. 13, registering the fabrication coordinate system may include using a jig and active illumination for alignment during fabrication. By registering the fabrication coordinate system to the determined spatial position, the optical structures maybe precisely positioned relative to the optical channels.

[0178] For arrayed first optical interfaces, registering the fabrication coordinate system may be performed independently for each of a plurality of optical channels. The method may include computing per-channel optical correction parameters based on measured positional offsets ofIRRA-M06-PCT the plurality of optical channels. Computing per-channel optical correction parameters may include determining beam position corrections, beam angle corrections, phase corrections for each of the plurality of optical channels, and / or other corrections depending on expected variations and application of the intended optical interconnect.

[0179] The per-channel optical correction parameters may be used in dynamically customizing design parameters for one or more optical structures. In one variation, the correction parameters may be used to customize individual component designs on a per-channel basis, where each channel receives a distinctly designed optical structure. In another variation, the correction parameters from multiple channels maybe used in altering design parameters of a single optical structure that spans multiple channels, such as with gradient-index regions or waveguiding structures. These design parameters maybe used in specifying or generating fabrication design for one or more optical structures.

[0180] Block S140, which includes nanofabricating at least one optical structure relative to the first optical interface, functions to form the optical elements that transform and direct optical fields between interfaces. The optical structures may be fabricated based on the registered fabrication coordinate system and any computed correction parameters from S130.

[0181] In one variation, nanofabricating may include depositing materials within a three-dimensional nanoporous scaffold. The nanoporous scaffold may comprise an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material. Depositing materials may include depositing polymers, metal chalcogenides, semiconductors, or metals within the scaffold. The deposited materials may be selected based on desired optical properties such as refractive index, transparency, or dispersion characteristics.

[0182] In another variation, nanofabricating may include volumetric lithographic writing of optical material. The volumetric lithographic writing may comprise two-photon polymerization or multiphoton absorption. This approach may enable the creation of arbitrary three-dimensional geometries with sub-micron feature resolution. The lithographic process may define optical structures with tailored gradients in refractive index contrast.

[0183] Nanofabricating (S140) may include forming various types of optical elements within the nanofabricated optical body. The optical elements formed may include one or more of the following or other suitable optical components or variations thereof. In addition to forming such optical elements they may be formed and arranged within a scaffold material for forming a collective optical system.

[0184] Nanofabricating may include forming optical correction structures configured to compensate for positional or angular variation of the second optical interface. The opticalIRRA-M06-PCT correction structures may be configured to bring optical outputs from a plurality of channels to a common deflection angle.

[0185] Nanofabricating may include forming an expansion region that expands a guided optical mode into an expanded optical beam. An expanded region may facilitate more relaxed alignment of the system when engaging with another optical system. The method may further include forming a compression region that focuses the expanded optical beam toward the second optical interface. The expanded optical beam may have a transverse diameter of at least too micrometers in some variations. The expansion region and the compression region may form a relay that maps a first localized optical mode to a second localized optical mode.

[0186] In some variations, nanofabricating may include forming gradient-index optical regions by spatially varying refractive index within a scaffold material. Forming gradient-index optical regions may include spatially selective material deposition, infiltration, or polymerization within the scaffold material.

[0187] In some variations, nanofabricating may include forming refractive optical surfaces including aspheric lenses, freeform lenses, or microlenses. Nanofabricating may include forming prism structures. Nanofabricating may include forming reflective surfaces configured for total internal reflection.

[0188] In some variations, nanofabricating may include forming diffractive optical elements including gratings, diffractive lenses, or holograms.

[0189] In some variations, nanofabricating may include forming wavelength-selective optical structures, polarization-selective optical structures, and / or mode-selective optical structures. Nanofabricating may include forming beam-splitting or beam-combining optical elements.

[0190] In some variations, nanofabricating may include forming mechanical alignment structures in addition to optical structures. The mechanical alignment structures may include alignment posts, sockets, grooves, mating surfaces, and / or other features configured to engage with corresponding features on the second optical interface or on an external fixture. The mechanical alignment structures may be formed concurrently with the optical structures using the same lithographic process, enabling precise registration between optical and mechanical features. The mechanical alignment structures may facilitate passive mechanical attachment by providing coarse positioning within the alignment tolerance enabled by the expanded-beam architecture. In some variations, these mechanical alignment structures maybe kinematic alignment structures such as Maxwell or Kevlin coupling.IRRA-M06-PCT

[0191] Where the first optical interface comprises a one-dimensional or two-dimensional array of optical channels, nanofabricating (S140) may include fabricating optical structures for each (or at least a plurality) of the plurality of optical channels. Alternatively, this may include fabricating an optical structure configured for optical interfaces for a plurality of optical channels. In one example, the arrayed first optical interface may comprise at least four optical channels. In another example, the arrayed first optical interface may comprise at least eight optical channels.

[0192] In one variation, the first optical interface may comprise a multicore optical fiber. Nanofabricating may include forming optical structures that spatially separate or combine optical channels from cores of the multicore optical fiber.

[0193] Fabricating optical structures for each of the plurality of optical channels may include forming channel-specific optical correction structures. Each channel may receive optical structures tailored to that channel's measured position and orientation.

[0194] In some variations, the method may include pre-characterizing a fiber array or other system planned for engagement with an optical interface prior to nanofabrication. Precharacterizing an optical system (such as a fiber array) may include measuring spatial positions, angular orientations, and / or optical properties of individual channels within the array. The characterization data may be stored and used to generate fabrication parameters for the nanofabricated optical body. The nanofabricated optical body may then be fabricated based on the stored characterization data, enabling the characterized fiber array to be connected to the optical interconnect at a later time. This pre-characterization approach may enable batch fabrication of nanofabricated optical bodies configured for specific fiber array types or enable fabrication to proceed in advance of final system assembly. In such a variation, the method may include engaging an instance of a pre-characterized fiber array (or any pre-characterized optical system) with the first optical interface or the second optical interface subsequent to forming of the nanofabricated optical body.

[0195] Where the first optical interface and the second optical interface have different array geometries, nanofabricating may include forming optical structures that map between the different array geometries. This may include mapping between different pitch spacings, between linear and two-dimensional arrays, or between other geometric arrangements.

[0196] In some variations, nanofabricating may include forming optical structures that provide an array offset, such as a vertical offset that lifts the optical path away from a chip edge to provide clearance for mechanical fixtures or other components. More generally, forming the optical structures may redirect optical path for any angular orientation (e.g., + / - 0-180°) andIRRA-M06-PCT displacement between a first optical interface and a second interface. For example, forming the optical structures may facilitate linearly aligned optical interfaces (e.g., + / - 50alignment) optionally with any transverse offset. In another exemplary variation, forming an optical structure may facilitate a perpendicular alignment (e.g., 80-100° alignment) of the first and second optical interfaces. In another exemplary variation, forming an optical structure may facilitate a U-turn routing (e.g., 135-2250), which maybe used when optical interfaces are arranged on the same side (e.g., two optical fibers connecting from the same general direction). Furthermore, such routing could change orientation in any suitable combination of angular dimensions.

[0197] More generally, the optical structures formed during nanofabricating (S140) may be designed for one or more of: correcting positional or angular variations, routing optical fields through desired paths, establishing optical pathways between two or more points, altering optical state (e.g., wavelength, polarization, or mode), and / or altering other optical properties. These functional purposes may be combined within a single nanofabricated optical body to address multiple requirements of the optical interconnect.

[0198] The nanofabrication process (S140) may be adapted based on the type of second optical interface.

[0199] Where the second optical interface comprises an edge coupler of a photonic integrated circuit, nanofabricating may include forming optical structures that focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler.

[0200] Where the second optical interface comprises a surface-normal interface of a photonic integrated circuit, nanofabricating may include forming optical structures configured for vertical coupling into or out of the photonic integrated circuit.

[0201] Nanofabricating may include forming optical structures that route the optical field through a non-collinear optical path. The non-collinear optical path may comprise an angular redirection of at least 45 degrees. The non-collinear optical path may comprise a 90-degree turn or a 180-degree turn.

[0202] In one variation, the non-collinear optical path may route light vertically away from an edge of a photonic integrated circuit. Nanofabricating may include forming a two-lens relay that lifts the optical path vertically away from the edge of the photonic integrated circuit.

[0203] Block S150, which includes performing a calibration step, functions to refine the nanofabrication process based on measured optical performance. The calibration step mayIRRA-M06-PCT include measuring an emitted optical field and adjusting a lithographic pattern based on the measurement.

[0204] In one variation, the calibration step may be performed during the nanofabrication process, enabling iterative refinement of optical structures. In another variation, the calibration step maybe performed after initial fabrication, with adjustments applied to subsequent fabrication runs or to additional structures within the same optical body.

[0205] Block S160, which includes mechanically positioning the second optical interface relative to the nanofabricated optical body without active optical alignment, functions to complete the optical interconnect assembly. Because the optical correction and alignment have been embedded into the nanofabricated optical body during S140, the second optical interface may be attached using passive mechanical positioning rather than active optical alignment.

[0206] Passive mechanical positioning refers to positioning based on mechanical references or structures (e.g., fixtures, alignment features, or mating surfaces) without requiring real-time optical feedback or active adjustment to optimize coupling. Mechanical references may include kinematic mounts (e.g., Maxwell coupling, Kelvin coupling), mechanical registration features, fixtures, alignment features, mating surfaces, vision-based alignment to mechanical fiducials, and / or other alignment features. The expanded beam architecture of the nanofabricated optical body may relax positioning tolerances, enabling reliable coupling even with mechanical positioning alone.

[0207] Mechanically positioning may comprise bonding using an adhesive, a thermal cure, an ultraviolet cure, a solder bond, a glass frit bond, and / or any suitable bonding or fixturing approach. These bonding approaches maybe used where the second optical interface is rigidly and permanently attached to the nanofabricated optical body.

[0208] Alternatively, the second optical interface may include a connector interface configured for selective engagement and disengagement with external optical systems. In this variation, the nanofabricated optical body may be permanently attached to a first optical interface, and external optical systems may be coupled and decoupled at the second optical interface via the connector.

[0209] In some variations, mechanically positioning (S160) may include engaging mechanical alignment structures of a passive mechanical attachment. The mechanical alignment structures may provide coarse positioning of the second optical interface within the alignment tolerance enabled by the expanded-beam architecture. Where the mechanical alignment structures are nanofabricated structures, the method may include forming at least a portion of the mechanical alignment structures during nanofabricating (S140). The mechanical alignmentIRRA-M06-PCT structures formed during S140 may be configured to engage with corresponding mechanical alignment structures on the second optical interface or on an external fixture. This approach enables precise registration between optical structures and mechanical alignment structures, as both are defined relative to the same fabrication coordinate system established in S130.4. Exemplary Variations

[0210] Hereafter are described different aspects of various variations of the systems and methods. These aspects are not intended to limit the systems and methods and do not include every variation and combination of variations described herein. Features which are described in the context of separate aspects and variations maybe used together and / or be interchangeable. Similarly, features described in the context of a single variation may also be provided separately or in any suitable sub-combination.

[0211] Variation 1.1: An optical interconnect system comprising: a first optical interface; a second optical interface; and a nanofabricated optical body disposed between the first optical interface and the second optical interface, wherein the nanofabricated optical body is configured to transform an optical field associated with the first optical interface into a spatially expanded optical field and to direct the spatially expanded optical field toward the second optical interface.

[0212] Variation 2.1: A method for producing an optical interconnect, the method comprising: providing a first optical interface; determining a spatial position of an optical feature associated with the first optical interface; registering a fabrication coordinate system to the determined spatial position; and nanofabricating at least one optical structure relative to the first optical interface, wherein the at least one nanofabricated optical body is configured to transform an optical field associated with the first optical interface into a spatially expanded optical field and to direct the spatially expanded optical field toward a second optical interface.

[0213] Variation 3.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is lithographically aligned to the first optical interface.

[0214] Variation 3.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes optical correction structures that adjust beam position, beam angle, or optical phase.IRRA-M06-PCT

[0215] Variation 3.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is lithographically aligned to a fiber core of the first optical interface.

[0216] Variation 4.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body comprises optical structures formed by depositing materials within a three-dimensional nanoporous scaffold.

[0217] Variation 4.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the optical structures are formed by two-photon polymerization or multiphoton absorption within the nanoporous scaffold.

[0218] Variation 4.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanoporous scaffold comprises an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material.

[0219] Variation 4.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the deposited materials comprise polymers, metal chalcogenides, semiconductors, or metals.

[0220] Variation 4.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises depositing materials within a three-dimensional nanoporous scaffold.

[0221] Variation 4.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises volumetric lithographic writing of optical material.

[0222] Variation 4.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein volumetric lithographic writing comprises two-photon polymerization or multiphoton absorption.

[0223] Variation 4.8: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanoporous scaffold comprises an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material.

[0224] Variation 4.9: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein depositing materials comprises depositing polymers, metal chalcogenides, semiconductors, or metals.

[0225] Variation 5.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes channel-specific optical correction structures configured to independently compensate for positional or angular variation for each of a plurality of optical channels.IRRA-M06-PCT

[0226] Variation 5.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the channel-specific optical correction structures are configured to bring optical outputs from a plurality of channels to a common deflection angle.

[0227] Variation 5.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein determining the spatial position and registering the fabrication coordinate system are performed independently for each of a plurality of optical channels of an arrayed first optical interface.

[0228] Variation 5.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, further comprising computing per-channel optical correction parameters based on measured positional offsets of the plurality of optical channels.

[0229] Variation 5.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming optical correction structures configured to compensate for positional or angular variation of the second optical interface.

[0230] Variation 5.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein computing per-channel optical correction parameters comprises determining beam position corrections, beam angle corrections, or phase corrections for each of the plurality of optical channels.

[0231] Variation 5.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the optical correction structures are configured to bring optical outputs from a plurality of channels to a common deflection angle.

[0232] Variation 5.8: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein fabricating optical structures for each of the plurality of optical channels comprises forming channel-specific optical correction structures.

[0233] Variation 6.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface or the second optical interface comprises an array of optical channels arranged in a one-dimensional or two-dimensional configuration.

[0234] Variation 6.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the array of optical channels comprises at least four optical channels.

[0235] Variation 6.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the array of optical channels comprises at least eight optical channels.

[0236] Variation 6.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is configured to map between a first array geometry of the first optical interface and a second array geometry of the second optical interface that differs from the first array geometry in pitch, orientation, or spatial arrangement.IRRA-M06-PCT

[0237] Variation 6.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first array geometry comprises a linear array and the second array geometry comprises a two-dimensional array, or wherein the first array geometry comprises a two-dimensional array and the second array geometry comprises a linear array.

[0238] Variation 6.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first array geometry and the second array geometry have different pitch spacings.

[0239] Variation 6.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface comprises a one-dimensional or two-dimensional array of optical channels, and wherein nanofabricating comprises fabricating optical structures for each of the plurality of optical channels.

[0240] Variation 6.8: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the arrayed first optical interface comprises at least four optical channels.

[0241] Variation 6.9: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the arrayed first optical interface comprises at least eight optical channels.

[0242] Variation 6.10: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface and the second optical interface have different array geometries, and wherein nanofabricating comprises forming optical structures that map between the different array geometries.

[0243] Variation 6.11: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the method further comprises pre-characterizing a fiber array prior to nanofabrication, storing characterization data, and nanofabricating the optical body based on the stored characterization data, enabling the characterized fiber array to be connected to the optical interconnect at a later time.

[0244] Variation 7.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface or the second optical interface comprises a multicore optical fiber.

[0245] Variation 7.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is configured to spatially separate optical channels from cores of the multicore optical fiber or to spatially combine optical channels into cores of the multi core optical fiber.IRRA-M06-PCT

[0246] Variation 7.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface comprises a multicore optical fiber.

[0247] Variation 7.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming optical structures that spatially separate or combine optical channels from cores of the multicore optical fiber.

[0248] Variation 8.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface comprises an edge coupler of a photonic integrated circuit.

[0249] Variation 8.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is configured to focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler.

[0250] Variation 8.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is configured to route the optical field through an angular redirection for directing the optical field to a lateral facet of the photonic integrated circuit.

[0251] Variation 8.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body routes the optical field vertically away from an edge of the photonic integrated circuit before directing the optical field to the edge coupler.

[0252] Variation 8.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface comprises an edge coupler of a photonic integrated circuit.

[0253] Variation 8.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming optical structures that focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler.

[0254] Variation 8.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming a two-lens relay that lifts the optical path vertically away from the edge of the photonic integrated circuit.

[0255] Variation 9.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface comprises a surface-normal interface of a photonic integrated circuit.IRRA-M06-PCT

[0256] Variation 9.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface comprises a surface-normal interface of a photonic integrated circuit.

[0257] Variation 10.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface or the second optical interface comprises a vertical-cavity surface-emitting laser, a light-emitting diode, or a photodetector.

[0258] Variation 11.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes gradient-index optical regions.

[0259] Variation 11.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes one or more refractive optical surfaces.

[0260] Variation 11.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes one or more reflective surfaces.

[0261] Variation 11.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the gradient-index optical regions comprise GRIN lenses or GRIN Fresnel lenses.

[0262] Variation 11.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the refractive optical surfaces comprise aspheric lenses, freeform lenses, or microlenses.

[0263] Variation 11.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the reflective surfaces are configured for total internal reflection.

[0264] Variation 11.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming gradient-index optical regions by spatially varying refractive index within a scaffold material.

[0265] Variation 11.8: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein forming gradient-index optical regions comprises spatially selective material deposition, infiltration, or polymerization within the scaffold material.

[0266] Variation 11.9: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming refractive optical surfaces including aspheric lenses, freeform lenses, or microlenses.IRRA-M06-PCT

[0267] Variation 11.10: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming reflective surfaces configured for total internal reflection.

[0268] Variation 11.11: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming prism structures.

[0269] Variation 12.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body is configured to route the optical field through a non-collinear optical path including an angular redirection of at least 45 degrees.

[0270] Variation 12.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the angular redirection comprises a 90-degree turn or a 180-degree turn.

[0271] Variation 12.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises optical structures that route the optical field through a non-collinear optical path.

[0272] Variation 12.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the non-collinear optical path routes light vertically away from an edge of a photonic integrated circuit.

[0273] Variation 12.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the non-collinear optical path comprises an angular redirection of at least 45 degrees.

[0274] Variation 12.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the non-collinear optical path comprises a 90-degree turn or a 180-degree turn.

[0275] Variation 13.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes waveguiding regions.

[0276] Variation 13.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the waveguiding regions are configured for fan-in or fan-out routing of a plurality of optical channels.

[0277] Variation 14.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes wavelength-selective optical structures.

[0278] Variation 14.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes polarization-selective optical structures.IRRA-M06-PCT

[0279] Variation 14.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes mode-selective optical structures.

[0280] Variation 14.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the wavelength-selective optical structures comprise dispersive elements or grating structures.

[0281] Variation 14.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming wavelength-selective optical structures.

[0282] Variation 14.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming polarization-selective optical structures.

[0283] Variation 14.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming mode-selective optical structures.

[0284] Variation 15.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface is mechanically positioned relative to the nanofabricated optical body without active optical alignment.

[0285] Variation 15.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, further comprising mechanically positioning the second optical interface relative to the nanofabricated optical body without active optical alignment.

[0286] Variation 15.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein mechanically positioning comprises bonding using an adhesive, a thermal cure, an ultraviolet cure, a solder bond, or a glass frit bond.

[0287] Variation 15.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes mechanical alignment structures configured to engage with corresponding features on the second optical interface or on an external fixture, the mechanical alignment structures facilitating passive mechanical attachment.

[0288] Variation 15.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface is a passive mechanical attachment interface.

[0289] Variation 15.6: A variation of Variation 15.5, wherein the passive mechanical attachment interface includes mechanical alignment structures.IRRA-M06-PCT

[0290] Variation 15.7: A variation of Variation 15.6, wherein the mechanical alignment structures comprise nanofabricated structures formed within the three-dimensional nanoporous scaffold.

[0291] Variation 15.8: A variation of Variation 15.6, wherein the mechanical alignment structures comprise kinematic coupling features.

[0292] Variation 15.9: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the second optical interface is a passive mechanical attachment interface.

[0293] Variation 15.10: A variation of Variation 15.9, wherein the passive mechanical attachment interface includes mechanical alignment structures, and wherein nanofabricating further comprises forming at least a portion of the mechanical alignment structures.

[0294] Variation 15.11: A variation of Variation 15.10, wherein the mechanical alignment structures comprise nanofabricated structures formed within the three-dimensional nanoporous scaffold during nanofabricating.

[0295] Variation 15.12: A variation of Variation 15.10, wherein the mechanical alignment structures comprise kinematic coupling features.

[0296] Variation 16.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein determining the spatial position comprises imaging a fiber core at a fiber endface of the first optical interface.

[0297] Variation 16.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein determining the spatial position comprises imaging fiducial features associated with the first optical interface.

[0298] Variation 16.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein determining the spatial position comprises imaging light emitted from the first optical interface to determine a mode center, mode profile, or pointing angle.

[0299] Variation 16.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein imaging the fiber core comprises optical microscopy, fluorescence microscopy, or confocal microscopy.

[0300] Variation 16.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein determining the spatial position achieves sub-micron precision.

[0301] Variation 17.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming an expansion region that expands a guided optical mode into an expanded optical beam.IRRA-M06-PCT

[0302] Variation 17.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, further comprising forming a compression region that focuses the expanded optical beam toward the second optical interface.

[0303] Variation 17.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body comprises a relay that maps the optical field from a first localized optical mode to a second localized optical mode through the spatially expanded optical field.

[0304] Variation 17.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the spatially expanded optical field has a transverse diameter of at least 100 micrometers.

[0305] Variation 17.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the expanded optical beam has a transverse diameter of at least 100 micrometers.

[0306] Variation 17.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the expansion region and the compression region form a relay that maps a first localized optical mode to a second localized optical mode.

[0307] Variation 18.1: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface comprises a fiber array unit or a fiber connector.

[0308] Variation 18.2: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the fiber connector comprises a multi-fiber push-on connector or a multi-fiber termination push-on connector.

[0309] Variation 18.3: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body achieves sub-micron alignment precision relative to the first optical interface.

[0310] Variation 18.4: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes beam-splitting or beamcombining optical elements.

[0311] Variation 18.5: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes diffractive optical elements.

[0312] Variation 18.6: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the diffractive optical elements comprise gratings, diffractive lenses, or holograms.IRRA-M06-PCT

[0313] Variation 18.7: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the nanofabricated optical body includes metasurface optical elements or three-dimensional meta-volume optical elements.

[0314] Variation 18.8: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming diffractive optical elements including gratings, diffractive lenses, or holograms.

[0315] Variation 18.9: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, further comprising performing a calibration step in which an emitted optical field is measured and a lithographic pattern is adjusted based on the measurement.

[0316] Variation 18.10: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein the first optical interface comprises a fiber array unit or a fiber connector.

[0317] Variation 18.11: A variation of Variations 1.1, 2.1, and / or any other system or method variation herein, wherein nanofabricating comprises forming beam-splitting or beamcombining optical elements.

[0318] As used herein, first, second, third, etc. are used to characterize and distinguish various elements, components, regions, layers and / or sections. These elements, components, regions, layers and / or sections should not be limited by these terms. Use of numerical terms maybe used to distinguish one element, component, region, layer and / or section from another element, component, region, layer and / or section. Use of such numerical terms does not imply a sequence or order unless clearly indicated by the context. Such numerical references may be used interchangeably without departing from the teaching of the embodiments and variations herein.

[0319] As a person skilled in the art will recognize from the previous detailed description and from the figures and claims, modifications and changes can be made to the embodiments of the invention without departing from the scope of this invention as defined in the following claims.

Claims

IRRA-M06-PCT CLAIMSWe Claim:

1. An optical interconnect system comprising: a first optical interface; a second optical interface; and a nanofabricated optical body disposed between the first optical interface and the second optical interface, wherein the nanofabricated optical body comprises optical structures formed by depositing materials within a three- dimensional nanoporous scaffold, wherein the nanofabricated optical body is configured to transform an optical field associated with the first optical interface into a spatially expanded optical field and to direct the spatially expanded optical field toward the second optical interface.

2. The optical interconnect system of claim 1, wherein the nanofabricated optical body is lithographically aligned to the first optical interface.

3. The optical interconnect system of claim 1, wherein the nanofabricated optical body comprises multiple optically functional regions monolithically integrated within the three-dimensional nanoporous scaffold.

4. The optical interconnect system of claim 1, wherein the optical structures are formed by two-photon polymerization or multiphoton absorption within the nanoporous scaffold.

5. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes channel-specific optical correction structures configured to independently compensate for positional or angular variation for each of a plurality of optical channels.

6. The optical interconnect system of claim 1, wherein the first optical interface or the second optical interface comprises an array of optical channels arranged in a onedimensional or two-dimensional configuration.

7. The optical interconnect system of claim 1, wherein the first optical interface or the second optical interface comprises a multicore optical fiber.

8. The optical interconnect system of claim 7, wherein the nanofabricated optical body is configured to spatially separate optical channels from cores of the multicore optical fiber or to spatially combine optical channels into cores of the multicore optical fiber.IRRA-M06-PCT 9. The optical interconnect system of claim 1, wherein the second optical interface comprises an edge coupler of a photonic integrated circuit.

10. The optical interconnect system of claim 1, wherein the second optical interface comprises a surface-normal interface of a photonic integrated circuit.

11. The optical interconnect system of claim 1, wherein the first optical interface or the second optical interface comprises a vertical-cavity surface-emitting laser, a lightemitting diode, or a photodetector.

12. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes gradient-index optical regions.

13. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes one or more refractive optical surfaces.

14. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes one or more reflective surfaces.

15. The optical interconnect system of claim 1, wherein the nanofabricated optical body is configured to route the optical field through a non-collinear optical path including an angular redirection of at least 45 degrees.

16. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes waveguiding regions.

17. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes wavelength-selective optical structures.

18. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes polarization-selective optical structures.

19. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes mode-selective optical structures.

20. The optical interconnect system of claim 1, wherein the second optical interface is mechanically positioned relative to the nanofabricated optical body without active optical alignment.

21. A method for producing an optical interconnect, the method comprising:providing a first optical interface;determining a spatial position of an optical feature associated with the first optical interface;IRRA-M06-PCT registering a fabrication coordinate system to the determined spatial position; andnanofabricating at least one optical structure relative to the first optical interface, wherein the at least one nanofabricated optical body is configured to transform an optical field associated with the first optical interface into a spatially expanded optical field and to direct the spatially expanded optical field toward a second optical interface.

22. The method of claim 21, further comprising mechanically positioning the second optical interface relative to the nanofabricated optical body without active optical alignment.

23. The method of claim 21, wherein nanofabricating comprises depositing materials within a three-dimensional nanoporous scaffold.

24. The method of claim 21, wherein determining the spatial position comprises imaging a fiber core at a fiber endface of the first optical interface.

25. The method of claim 21, wherein determining the spatial position comprises imaging fiducial features associated with the first optical interface.

26. The method of claim 21, wherein determining the spatial position comprises imaging light emitted from the first optical interface to determine a mode center, mode profile, or pointing angle.

27. The method of claim 21, wherein determining the spatial position and registering the fabrication coordinate system are performed independently for each of a plurality of optical channels of an arrayed first optical interface.

28. The method of claim 27, further comprising computing per-channel optical correction parameters based on measured positional offsets of the plurality of optical channels.

29. The method of claim 21, wherein nanofabricating comprises forming optical correction structures configured to compensate for positional or angular variation of the second optical interface.

30. The method of claim 21, wherein nanofabricating comprises forming an expansion region that expands a guided optical mode into an expanded optical beam.IRRA-M06-PCT 31. The method of claim 30, further comprising forming a compression region that focuses the expanded optical beam toward the second optical interface.

32. The method of claim 21, wherein nanofabricating comprises volumetric lithographic writing of optical material.

33. The method of claim 32, wherein volumetric lithographic writing comprises two- photon polymerization or multiphoton absorption.

34. The method of claim 21, wherein the first optical interface comprises a onedimensional or two-dimensional array of optical channels, and wherein nanofabricating comprises fabricating optical structures for each of the plurality of optical channels.

35. The method of claim 34, wherein the first optical interface comprises a multicore optical fiber.

36. The method of claim 21, wherein the second optical interface comprises an edge coupler of a photonic integrated circuit.

37. The method of claim 21, wherein the second optical interface comprises a surfacenormal interface of a photonic integrated circuit.

38. The method of claim 21, wherein nanofabricating comprises forming gradient-index optical regions by spatially varying refractive index within a scaffold material.

39. The method of claim 21, wherein nanofabricating comprises forming optical structures that route the optical field through a non-collinear optical path.

40. The method of claim 39, wherein the non-collinear optical path routes light vertically away from an edge of a photonic integrated circuit.

41. The optical interconnect system of claim 2, wherein the nanofabricated optical body includes optical correction structures that adjust beam position, beam angle, or optical phase.

42. The optical interconnect system of claim 2, wherein the nanofabricated optical body is lithographically aligned to a fiber core of the first optical interface.

43. The optical interconnect system of claim 1, wherein the nanoporous scaffold comprises an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material.IRRA-M06-PCT 44- The optical interconnect system of claim 1, wherein the deposited materials comprise polymers, metal chalcogenides, semiconductors, or metals.

45. The optical interconnect system of claim 5, wherein the channel-specific optical correction structures are configured to bring optical outputs from a plurality of channels to a common deflection angle.

46. The optical interconnect system of claim 6, wherein the array of optical channels comprises at least four optical channels.

47. The optical interconnect system of claim 6, wherein the array of optical channels comprises at least eight optical channels.

48. The optical interconnect system of claim 6, wherein the nanofabricated optical body is configured to map between a first array geometry of the first optical interface and a second array geometry of the second optical interface that differs from the first array geometry in pitch, orientation, or spatial arrangement.

49. The optical interconnect system of claim 48, wherein the first array geometry comprises a linear array and the second array geometry comprises a two- dimensional array, or wherein the first array geometry comprises a two-dimensional array and the second array geometry comprises a linear array.

50. The optical interconnect system of claim 48, wherein the first array geometry and the second array geometry have different pitch spacings.

51. The optical interconnect system of claim 9, wherein the nanofabricated optical body is configured to focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler.

52. The optical interconnect system of claim 9, wherein the nanofabricated optical body is configured to route the optical field through an angular redirection for directing the optical field to a lateral facet of the photonic integrated circuit.

53. The optical interconnect system of claim 9, wherein the nanofabricated optical body routes the optical field vertically away from an edge of the photonic integrated circuit before directing the optical field to the edge coupler.

54. The optical interconnect system of claim 12, wherein the gradient-index optical regions comprise GRIN lenses or GRIN Fresnel lenses.IRRA-M06-PCT 55- The optical interconnect system of claim 13, wherein the refractive optical surfaces comprise aspheric lenses, freeform lenses, or microlenses.

56. The optical interconnect system of claim 14, wherein the reflective surfaces are configured for total internal reflection.

57. The optical interconnect system of claim 15, wherein the angular redirection comprises a 90-degree turn or a 180-degree turn.

58. The optical interconnect system of claim 16, wherein the waveguiding regions are configured for fan-in or fan-out routing of a plurality of optical channels.

59. The optical interconnect system of claim 17, wherein the wavelength-selective optical structures comprise dispersive elements or grating structures.

60. The optical interconnect system of claim 1, wherein the nanofabricated optical body comprises a relay that maps the optical field from a first localized optical mode to a second localized optical mode through the spatially expanded optical field.

61. The optical interconnect system of claim 1, wherein the first optical interface comprises a fiber array unit or a fiber connector.

62. The optical interconnect system of claim 61, wherein the fiber connector comprises a multi-fiber push-on connector or a multi-fiber termination push-on connector.

63. The optical interconnect system of claim 1, wherein the spatially expanded optical field has a transverse diameter of at least too micrometers.

64. The optical interconnect system of claim 1, wherein the nanofabricated optical body achieves sub-micron alignment precision relative to the first optical interface.

65. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes beam-splitting or beam-combining optical elements.

66. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes diffractive optical elements.

67. The optical interconnect system of claim 66, wherein the diffractive optical elements comprise gratings, diffractive lenses, or holograms.

68. The optical interconnect system of claim 1, wherein the nanofabricated optical body includes metasurface optical elements or three-dimensional meta-volume optical elements.IRRA-M06-PCT 69. he method of claim 22, wherein mechanically positioning comprises bonding using an adhesive, a thermal cure, an ultraviolet cure, a solder bond, or a glass frit bond.

70. The method of claim 23, wherein the nanoporous scaffold comprises an aerogel, a polymeric scaffold, a porous glass, or a porosified semiconductor material.

71. The method of claim 23, wherein depositing materials comprises depositing polymers, metal chalcogenides, semiconductors, or metals.

72. The method of claim 24, wherein imaging the fiber core comprises optical microscopy, fluorescence microscopy, or confocal microscopy.

73. The method of claim 27, wherein the arrayed first optical interface comprises at least four optical channels.

74. The method of claim 27, wherein the arrayed first optical interface comprises at least eight optical channels.

75. The method of claim 28, wherein computing per-channel optical correction parameters comprises determining beam position corrections, beam angle corrections, or phase corrections for each of the plurality of optical channels.

76. The method of claim 29, wherein the optical correction structures are configured to bring optical outputs from a plurality of channels to a common deflection angle.

77. The method of claim 30, wherein the expanded optical beam has a transverse diameter of at least too micrometers.

78. The method of claim 31, wherein the expansion region and the compression region form a relay that maps a first localized optical mode to a second localized optical mode.

79. The method of claim 34, wherein fabricating optical structures for each of the plurality of optical channels comprises forming channel-specific optical correction structures.

80. The method of claim 35, wherein nanofabricating comprises forming optical structures that spatially separate or combine optical channels from cores of the multicore optical fiber.

81. The method of claim 36, wherein nanofabricating comprises forming optical structures that focus the spatially expanded optical field to a spot size compatible with a waveguide mode of the edge coupler.IRRA-M06-PCT 82. The method of claim 38, wherein forming gradient-index optical regions comprises spatially selective material deposition, infiltration, or polymerization within the scaffold material.

83. The method of claim 39, wherein the non-collinear optical path comprises an angular redirection of at least 45 degrees.

84. The method of claim 39, wherein the non-collinear optical path comprises a 90- degree turn or a 180-degree turn.

85. The method of claim 40, wherein nanofabricating comprises forming a two-lens relay that lifts the optical path vertically away from the edge of the photonic integrated circuit.

86. The method of claim 21, wherein nanofabricating comprises forming refractive optical surfaces including aspheric lenses, freeform lenses, or microlenses.

87. The method of claim 21, wherein nanofabricating comprises forming reflective surfaces configured for total internal reflection.

88. The method of claim 21, wherein nanofabricating comprises forming prism structures.

89. The method of claim 21, wherein nanofabricating comprises forming diffractive optical elements including gratings, diffractive lenses, or holograms.

90. The method of claim 21, further comprising performing a calibration step in which an emitted optical field is measured and a lithographic pattern is adjusted based on the measurement.

91. The method of claim 21, wherein the first optical interface comprises a fiber array unit or a fiber connector.

92. The method of claim 21, wherein determining the spatial position achieves submicron precision.

93. The method of claim 21, wherein nanofabricating comprises forming wavelength- selective optical structures.

94. The method of claim 21, wherein nanofabricating comprises forming polarization- selective optical structures.

95. The method of claim 21, wherein nanofabricating comprises forming mode-selective optical structures.IRRA-M06-PCT 96. The method of claim 21, wherein nanofabricating comprises forming beam-splitting or beam-combining optical elements.

97. The method of claim 34, wherein the first optical interface and the second optical interface have different array geometries, and wherein nanofabricating comprises forming optical structures that map between the different array geometries.

98. The method of claim 21, further comprising pre-characterizing a fiber array prior to nanofabricating, storing characterization data from the pre-characterizing, and wherein nanofabricating is based on the stored characterization data.

99. The method of claim 21, wherein nanofabricating further comprises forming mechanical alignment structures configured to engage with corresponding features on the second optical interface or on an external fixture.

100. The optical interconnect system of claim 1, wherein the second optical interface is a passive mechanical attachment interface.

101. The optical interconnect system of claim 100, wherein the passive mechanical attachment interface includes mechanical alignment structures.

102. The optical interconnect system of claim too, wherein the mechanical alignment structures comprise nanofabricated structures formed within the three- dimensional nanoporous scaffold.

103. The optical interconnect system of claim 101, wherein the mechanical alignment structures comprise kinematic coupling features.

104. The method of claim 21, wherein the second optical interface is a passive mechanical attachment interface.

105. The method of claim 104, wherein the passive mechanical attachment interface includes mechanical alignment structures, and wherein nanofabricating further comprises forming at least a portion of the mechanical alignment structures.

106. The method of claim 102, wherein the mechanical alignment structures comprise nanofabricated structures formed within the three-dimensional nanoporous scaffold during nanofabricating.

107. The method of claim 105, wherein the mechanical alignment structures comprise kinematic coupling features.

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