Volumetric optical device

Abstract

An apparatus includes a porous scaffold characterized by a scaffold refractive index. The optically written optical component is embedded in the porous scaffold. The coating forms a surface of the porous scaffold. The coating includes a surface and a transition region. The surface is characterized by a surface refractive index. The transition region features a refractive index gradient that transitions between the surface refractive index and the stent refractive index.

Description

[0001] Statement Regarding Federally Sponsored Research or Development

[0002] This invention was made with government support under National Science Foundation grant number 1935289. The government has certain rights in the invention.

[0003] Priority

[0004] This application claims the priority of U.S. Provisional Application No. 63 / 412,107, filed on September 30, 2022, Attorney Docket No. 010422 - 22001A - US, entitled "Volumetric Optical Device", the entire content of which is incorporated herein by reference. Technical Field

[0005] This disclosure generally relates to volumetric optical devices. Background Art

[0006] Driven by huge customer demand, communication technologies have developed rapidly, leading to the widespread use of optical communication media. As an example, millions of miles of optical fiber provide short - and long - distance optical communication worldwide. Improved interconnects, optical processing, and integration with semiconductor - based electronic devices will continue to increase demand. Brief Description of the Drawings

[0007] Figure 1 Shows an exemplary porous scaffold.

[0008] Figure 2 Shows an exemplary coating manufacturing method.

[0009] Figure 3 Shows an exemplary porous scaffold.

[0010] Figure 4 Shows an exemplary multi - session optical component.

[0011] Figure 5 Shows an exemplary multi - session optical component writing method.

[0012] Figure 6 Shows an exemplary spherical optical component having multiple step - index layers.

[0013] Figure 7 Shows an exemplary porous scaffold having an exemplary waveguide.

[0014] Figure 8 Shows an exemplary bending logic.

[0015] Figure 9 Shows an exemplary bending calculation circuit.

[0016] Figure 10Displays a voxel array of exemplary two-dimensional optical writing.

[0017] Figure 11 Displays exemplary illumination logic.

[0018] Figure 12 Displays an exemplary illumination control circuit.

[0019] Figure 13 Displays exemplary multi-pass optical writing logic.

[0020] Figure 14 Displays exemplary dither logic.

[0021] Figure 15 Displays an exemplary multi-pass circuit.

[0022] Figure 16 Displays exemplary spacing logic.

[0023] Figure 17 Displays an exemplary moving spacing circuit.

[0024] Figure 18 Displays a set of written objects of an illustrative example.

[0025] Figure 19 Displays a set of analysis objects of an illustrative example.

[0026] Figure 20 Displays exemplary position control logic.

[0027] Figure 21 Displays an exemplary position control circuit.

[0028] Figure 22 Displays an exemplary porous scaffold with multiple voxel arrays written thereon.

[0029] Figure 23 Displays exemplary visibility criterion logic. Detailed Description

[0030] In many cases, volume-integrated photon devices can be integrated with other optical and / or photon devices. Thus, methods and devices for improving integration, reducing insertion loss, and enhancing the overall quality of photon devices will improve performance and drive the application of the technology.

[0031] The various techniques and architectures discussed below provide devices for coupling, free-space to guided-mode conversion, device writing with reduced writing artifacts and errors, waveguide bends, anti-reflection coatings, and / or other volume-integrated photon device configurations and manufacturing methods.

[0032] In various systems, such as optical interconnections where an optical element couples one or more optical media interfaces to one or more other media (including other optical media), a specific three-dimensional form is utilized to couple light between the media. Additionally, for complex and / or multiplexed routing and / or filtering, complex three-dimensional forms can be used. In some cases, processing operations on optical signals can use complex and / or specific-sized forms. Further, in some cases, lensing can use two-dimensional or three-dimensional forms of complex nature (e.g., as opposed to a curved lens or a simple planar form such as a Fresnel lens), and these forms can be designed through computer modeling or empirical studies. It may be difficult or impossible to create or precisely align such complex two-dimensional or three-dimensional forms using only standard lens manufacturing techniques. Thus, technologies and architectures that allow for the creation of monolithic integrated optical devices, electro-optic devices, photonic components, interconnections, waveguides, prisms, and / or other optical components of arbitrary size, functionality, and form, such as the technologies and architectures discussed below involving writing one or more voxels into a scaffold and / or writing optical components into such a scaffold, provide an improvement over existing market-based solutions.

[0033] In some systems, when a form is written into a medium, the lower part of the form provides support for the upper part of the form because a writable medium (e.g., a liquid or water-based polymer) does not provide physical rigidity unless hardened by exposure. Thus, the conventional view is that when constructing via laser writing (e.g., writing into a polymer medium), the form of the optical component should be selected such that the lower part of the form supports the upper part. In some cases, including a scaffold within the intrinsically writable medium provides rigidity, allowing forms without support from the lower part of the structure, which allows one to make structural choices that may be contrary to the conventional view.

[0034] The scaffold can be soaked or immersed in a writable medium to define a writable volume. The scaffold can be porous, can accommodate the writable medium, and can be transparent both in the presence of the writable medium and when the writable medium is removed (e.g., after writing is completed, or for an additional writing phase, to allow a second writable medium to replace the first writable medium). The writable medium can include a medium whose refractive index can change if the medium undergoes a change in material properties, such as an optically induced or driven change. Voxels can be written into the scaffold to fabricate an optical component. The scaffold can be disposed on a substrate (e.g., a silicon-on-insulator (SOI)-compatible substrate, a III-V compatible substrate, or other substrate), which can allow integration with other optical components, electronic devices, and / or other systems. The scaffold can be rigid (e.g., a structure that can hold the written region in a certain position in three-dimensional space at least when undisturbed and / or when exposed to environmental conditions). However, in various embodiments, the scaffold can have different degrees of flexibility when exposed to specific deformation forces.

[0035] In an exemplary technique, voxels are generated within the scaffold. The voxels can include regions that have undergone a change in material properties such that the optical properties of the region change during an operating period (e.g., permanently, over hours / days / months / years, during a decay period, a dissolution period, or other duration during which the written voxels can be used as an optical component (at least a portion of the optical component)). The voxels can be written by focusing incident light into the voxels to cause a change in material properties. The change in material properties can include a change in refractive index, density, composition, mechanical properties, electrical properties, acoustic properties, or other material property changes that occur within the writable medium through light absorption. Additionally, the change in material properties can cause the position of the voxels to be fixed within the scaffold. One or more voxels can be used to define an optical component within the scaffold.

[0036] In other words, an optical component can be fabricated such that the optical component is written into at least partially optically transparent porous scaffold permeated with a writable medium. The optical component can be formed and arranged in a three-dimensional pattern. The optical component can include regions of the writable medium having a light-driven state change.

[0037] The scaffold includes at least a partially rigid region. The writable volume can be included within or overlap with the at least partially rigid region. The writable volume is defined via a writable medium that at least temporarily penetrates the scaffold. The writable medium can include a substance for which exposure to focused incident light can cause a change in material properties. In some cases, the light absorption process can include a linear absorption process. However, in some cases, the light absorption process includes a non-linear absorption process. For example, the process can include two-photon, three-photon, and / or multi-photon absorption processes. In some cases, using a non-linear absorption process can allow the position of a voxel to be localized to the region exposed to the beam focus. In some cases, higher-order non-linear absorption processes produce stronger localization compared to lower-order non-linear absorption processes. The higher the order of the non-linear absorption process, the more photons that must be absorbed simultaneously to excite the process. Thus, near (or at) the focus of a focused incident light source (e.g., a laser or a light-emitting diode (LED)), the likelihood of exciting the process will increase significantly (e.g., non-linearly). Thus, a voxel can include the focused volume (or some portion of the focused volume) of a focused incident light source.

[0038] In some cases, the writable volume (e.g., the writable medium therein) can include monomers, polymers, photoresists, or combinations thereof. As an illustrative example, pentaerythritol triacrylate can be used. As another illustrative example, the writable medium can include monomers that form self-assembled monolayers. In this and other monomer examples, after the monomers crosslink due to light absorption, the monomers can form polymers.

[0039] As described above, the scaffold can include a porous material. In various embodiments, the porous material can include porous silicon, porous silicate, porous silica, porous gallium nitride, porous gallium arsenide, porous indium phosphide, porous lithium niobate, other porous III-V materials, porous high-temperature high-silicon glass, any nanoporous fabricated substrate porous metal material, porous semiconductor material, and / or porous dielectric material. A specific scaffold can be selected based on the desired properties of the scaffold for a particular application. For example, porous silicon can be selected based on the birefringence of porous silicon. In an example, the birefringence of silicon can contribute to phase matching in a multi-wave mixing process.

[0040] In various embodiments, porous materials that have been made porous via various processes can be used. For example, materials that have been made porous by uniform or non-uniform chemical etching can be used as scaffolds. Materials that have been made porous by uniform or non-uniform physical etching can be used as scaffolds. Materials that have been made porous by uniform or non-uniform electrochemical etching can be used as scaffolds. Materials that have been made porous by lithographic etching can be used as scaffolds. Materials that have been made porous by spatially selective etching can be used as scaffolds. Materials that are porous due to deposition at a grazing angle can be used as scaffolds. Materials that form porosity by assembly or are porous due to assembly (including self-assembly) can be used as scaffolds. Preferably, porous materials with pores less than 1 micron in at least one dimension, or more preferably less than 100 nanometers, can be used as scaffolds. In some embodiments, the pore size can be controlled, for example, by controlling the electrochemical etching current density. For example, it can be selectively controlled to vary the pore size from 10 nm to 50 nm or greater.

[0041] In addition, the scaffold can be selected based on the transparency constraints of a particular embodiment. In various embodiments, the transparency of the scaffold allows the writable medium to be exposed to focused incident light. In some cases, an opaque scaffold or a scaffold with limited transparency can prevent (or at least partially inhibit) the exposure. Thus, the scaffold material can be constructed in various ways (such as any of the above or any other material made porous). However, regardless of the porous processing technique employed, a material that meets the transparency limitations can be selected (at least in some cases).

[0042] In some embodiments, the level / intensity of the material property change can be selected. For example, the exposure can be reduced (reducing the intensity or duration) to reduce the overall change that occurs (e.g., reducing the upward or downward change in refractive index). In another example, the exposure can be increased (increasing the intensity or duration) to increase the overall change that occurs (e.g., increasing the upward or downward change in refractive index). The intensity can be increased or decreased by adjusting the input power of the incident light. The intensity can also be increased or decreased by varying the duty cycle of pulse width modulation. In some cases, the intensity can be increased or decreased by adjusting the focused volume of the incident light. In some cases, the degree of material change can be increased or decreased by varying the total exposure time.

[0043] The light source of the incident light can be a laser, a light-emitting diode, a lamp, a flash lamp, an image projector, a fully or partially incoherent light source, and / or a fully or partially coherent light source.

[0044] Coating with a transition region

[0045] In various embodiments, coupling between one or more optical waveguide media may be desired. For example, in some scenarios, an operator may wish to couple multiple fiber-guided outputs into one or more inputs of a photonic chip and vice versa. In another example, an operator may wish to couple to or from a selected medium, yet still fabricate an optical device within a porous scaffold with a refractive index different from that of the selected medium. Thus, optical components written into a porous scaffold as described herein can effectuate coupling between media of different refractive indices. In some cases, reflection may occur when light traverses an interface where the refractive index shifts. Such reflection can result in losses or cause undesirable feedback into the light source when devices are coupled together.

[0046] In various embodiments where the volume of the porous scaffold can be characterized by a scaffold refractive index different from that of a selected medium coupled to the scaffold, coupling between the porous scaffold and the selected medium can be improved if the surface of the porous scaffold has a refractive index that matches the selected medium. Matching the refractive index of the porous scaffold surface to that of the selected medium ensures a reduction and / or elimination of reflection at the interface between the scaffold surface and the selected medium. However, matching the surface refractive index of the porous scaffold can result in reflection at the interface between the scaffold surface (at the refractive index of the selected medium) and the internal volume within the porous scaffold that is characterized by the scaffold refractive index.

[0047] The various techniques and structures discussed herein provide a transition region that is characterized by a refractive index gradient transitioning from the surface refractive index to the scaffold refractive index. Thus, various embodiments can include a porous scaffold having a coating that is characterized by a surface refractive index and a transition region having a refractive index gradient that permits a transition to the scaffold refractive index.

[0048] Figure 1 Exemplary porous scaffold 100 is shown. The scaffold can be characterized by a scaffold refractive index within an internal volume 120 of the scaffold, which internal volume 120 can include written optical component 122. The exemplary scaffold can include a coating 110 that is characterized by a surface refractive index at a surface 112 of the coating. Coating 110 can include a transition region 114 that is characterized by a refractive index gradient that transitions from the scaffold refractive index at a volume-coating interface 116 to the surface refractive index at surface 112. The volume-coating interface 116 can include the interface where coating 110 and internal volume 120 meet. In some embodiments, due to the porosity of the scaffold, internal volume 120 can be occupied by cavities (up to 80% to 90% or more). The scaffold refractive index (e.g., outside of the written optical component) can be close to the ambient refractive index, such as air, vacuum, and / or other surrounding environments.

[0049] In various embodiments, the coating 110 can be formed by diffusion and / or by other processes that can create a diffused volume - coating interface 116. Thus, a defined material boundary need not be formed between the volume - coating interface 116 and the internal volume 120. As discussed herein, the volume - coating interface 116 can be used for illustrative purposes rather than to represent a defined material boundary. Additionally, because the refractive index of the volume - coating interface matches that of the internal volume, the volume - coating interface 116 need not provide a visual or optical boundary, even in embodiments where the coating is different from the internal volume 120 in terms of material composition.

[0050] The coating 110 can facilitate the coupling between the coupling medium 130 and one or more optical components 122 written within the internal volume. The refractive index gradient of the coating 110 can ensure a gradual transition from the refractive index of the coupling medium 130 (e.g., a selected medium refractive index, and the surface refractive index matches that selected medium refractive index) to the refractive index within the internal volume 120. This gradual transition can prevent and / or reduce reflections when light propagates between the coupling medium 130 and the internal volume 120.

[0051] Figure 2 An exemplary coating manufacturing method 200 is shown. An optical component can be written into a porous scaffold (202). The cross - linking fluid that permeates the scaffold can be removed after writing to produce a developed scaffold (204) with the intact optical component. The surface of the scaffold can be coated with a coating (206) to create a refractive index gradient.

[0052] Generating a refractive index gradient may rely on various coating techniques for the coating.

[0053] In various embodiments, a coating can be applied by allowing a refractive index matching material (e.g., matching the refractive index of a selected coupling medium) to diffuse into a porous scaffold. The diffusion of the refractive index matching material creates a gradient based on the amount of material diffused. As the distance from the surface of the scaffold increases, the amount of refractive index matching material diffused to that depth decreases. Thus, due to the restricted movement of the diffused refractive index matching material, the ratio of scaffold material to refractive index matching material increases as the depth into the scaffold increases. The ratio of scaffold material to refractive index matching material defines the effective refractive index at any point within the coating. Thus, by diffusing the material into the scaffold, a diffusion profile, such as a concentration varying with depth, is created. The diffusion profile can define a depth-varying refractive index in a transition region. In some embodiments, the refractive index matching material is a liquid, and the viscosity and optical properties of the liquid are selected such that a desired refractive index profile is obtained after diffusion. In some cases, the refractive index matching material is transported via a carrier gas that diffuses into the pores and allows the material to adhere to the pore walls. In some cases, the refractive index matching material is a solid material such as a dielectric, which is evaporated and diffused into the pores.

[0054] Additionally or alternatively, a multilayer coating can be used to apply the coating. The multilayer coating can include depositing the coating layer by layer, where consecutive layers have different refractive indices. The different refractive indices of the consecutive layers gradually change from the surface refractive index on one side of the coating to the scaffold refractive index on the other side of the coating. For example, the coating can include silicon oxynitride layers, where different layers of the coating have different levels of silicon enrichment. In various examples, these layers can include different compositions of the SiNx system to achieve a progression of refractive indices between consecutive layers.

[0055] In various embodiments, a continuously varying (or continuously changing) deposition method can be used. For example, a deposition process with varying concentration and / or chemical composition can be used. For example, by depositing silica and gradually increasing the concentration of silicon oxynitride until pure silicon oxynitride is reached and finally transitioning to components in the silicon nitride system, a graded refractive index system can be created. In some cases, prior to the continuously varying deposition process, the porous scaffold can be filled by diffusion with silica. Various deposition processes can be easily combined to generate a larger refractive index gradient.

[0056] In some cases, the coating can be porous. For example, an electrochemical etching process similar to that used to produce porous scaffolds can be used to produce the coating. The current density of the electrochemical etching process can be adjusted during coating deposition such that the current density matches the current density used to create the internal volume at the volume-coating interface and then decreases as the distance from the internal volume increases to produce relatively more non-porous material at the coating surface. A quarter-wavelength thickness coating can be produced using the electrochemical etching process. A multi-layer anti-reflection coating having a set of discrete refractive indices or a continuously varying refractive index profile can be produced using the electrochemical etching process.

[0057] The coating can have different thicknesses, ranging from less than 1 micron for quarter-wavelength type coatings to several microns or more for multi-layer coatings and diffusion-based coatings.

[0058] A variety of silicons, including materials, semiconductor materials, glass materials, and / or other materials, can be used to form the coating, for example, to produce an implementable refractive index range from a refractive index close to that of the surrounding environment (e.g., air or vacuum) to a refractive index higher than that of silicon. Thus, almost any pair of coupled media refractive indices can have a customized coating that transitions from the refractive index of one medium to the refractive index of the other medium across the corresponding refractive index gradient of the coating.

[0059] End Coupler

[0060] In various embodiments, coupling between an external light source / target (e.g., an external waveguide) and a waveguide within a porous scaffold may be desired. In some cases, an end coupler structure can be used to improve coupling into (or out of) the porous scaffold waveguide. The end coupler structure can include an optically written optical component spaced (but close) to the end of the porous scaffold waveguide.

[0061] In various embodiments, various end coupler shapes can be used. For example, a spherical coupler can be used. In some embodiments, polyhedra, ellipsoids, irregular three-dimensional shapes, optical resonator shapes, and / or other forms can be used.

[0062] In some embodiments, the end coupler may have a uniform refractive index in its shape. In some embodiments, the refractive index of various parts of the end coupler may have different refractive indices, allowing the contrast and structural complexity within the device to be different from those brought about by the device shape. As an example, a Luneburg lens may be implemented. A Luneburg lens may be spherical and have a continuously varying refractive index along its radius. By changing the laser exposure time and / or power during optical writing, a refractive index that varies over the volume of various end couplers can be generated. Longer and / or stronger exposure can generate dense polymer crosslinking regions, resulting in an increase in the refractive index. Additionally or alternatively, multi-session writing as described below can be used to generate a varying refractive index.

[0063] In some embodiments, the shape of the end coupler can be designed to match a specific input source mode at one end and a porous scaffold waveguide mode at the other end. For example, the end coupler can be teardrop-shaped, allowing the circular end to be coupled to one source or output, and the tapered end to be coupled to another source / output. In some embodiments, the taper can be used to improve mode matching, for example, when the output mode of the waveguide is highly divergent.

[0064] In various embodiments, the porous scaffold waveguide can be tapered near the end of the end coupler to allow for more available configurations to improve mode matching between the end coupler and the porous scaffold waveguide. In some embodiments, the external light source / input can include a waveguide with a tapered end for coupling to the porous scaffold waveguide.

[0065] In some embodiments, the end coupler can be close to the end of the porous scaffold waveguide. For example, the end coupler can be in contact with the end of the waveguide, spaced apart from the end of the waveguide, and / or the end of the waveguide can terminate within the end coupler. For example, the waveguide with a tapered end can protrude slightly into the volume of the end coupler.

[0066] Figure 3 An exemplary porous scaffold 300 is shown. The porous scaffold 300 may have an end coupler 302 to support coupling to a waveguide 304 within the porous scaffold. The end coupler 302 can support coupling between an external waveguide 306 and the porous scaffold waveguide 304. As an illustrative example, the exemplary porous scaffold 300 is shown paired with an external waveguide 306, but other external sources / inputs can also be used. The end coupler 302 can be spaced apart from the porous scaffold waveguide 304. The porous scaffold waveguide 304 can include a tapered portion 314. The porous scaffold waveguide 304 can include a bend to enable the direction of light propagation at the output end to be different from that in the external waveguide.

[0067] In various embodiments, various methods can be used to write the end coupler, including: bottom-up writing (e.g., starting from the bottom of the optical component and writing upward), top-down writing (e.g., starting from the top of the optical component and writing downward), a hybrid of bottom-up and top-down (e.g., starting from the bottom of the optical component and writing upward, and then starting from the top of the taper and writing downward), and / or using various optical writing processes discussed below, using multi-session writing, multi-pass writing, dithering, transfer functions, frame stitching, equal time between actuator movements, laser stability analysis, and / or other writing processes.

[0068] Additionally or alternatively, the writing process can be a multi-session writing process. In a multi-session writing process, one or more overlapping writing sessions are used to write one or more optically written optical components. A single writing session within the writing sessions can use various optical writing processes discussed below, including: transfer functions, frame stitching, equal time between actuator movements, laser stability analysis, and / or other writing processes. Multi-pass writing can be used within a single session, in which the same or approximately the same positions of voxels are used to rewrite a specific line or frame. Multi-pass writing can be used to increase the refractive index contrast or reduce the roughness of the written features. Multi-session writing is different from multi-pass writing because multi-session writing includes (at least in part) rewriting the written positions with different shapes to produce a refractive index contrast. For example, a spherical coupler (e.g., a spherical lens) can be written in multiple sessions. The first session can be used to write a low refractive index sphere (e.g., using low laser power). The second session can be used to write a smaller concentric sphere with a higher resulting refractive index on the center of the low refractive index sphere (e.g., using high laser power or using low laser power for multi-pass writing). Thus, a spherical lens with a step refractive index change along the radius of the spherical lens is produced. Multi-session writing can be used to write other complex multi-refractive index optical components.

[0069] Figure 4 An exemplary multi-session optical component 400 is shown. Also refer to Figure 5, shows a multi-session optical component writing method that can be used to write a multi-session optical component 400. The multi-session optical component 400 can include a first region 402 and a second region 404. In an exemplary multi-session optical component 400, the second region 404 is included within the first region 402. However, in other examples, the smaller region is not necessarily completely included within the largest region. A first writing session can be used to write the first region (502). A second writing session can be used to write the second region (504). Although the sessions can be performed in a case where either session can be performed before the other, in various embodiments, the current session can be completed before the other session begins. The writing sessions can continue until all regions are written (506).

[0070] In this example, the second region 404 is included within the first region 402. Thus, the volume of the written voxels for the second session can be less than the volume in the first session and overlap with a portion of the voxels written in the first session. Thus, the second session can include a "subset session", while the first session can include a "superset session". In some cases, even though the volume of the subset is included within the volume of the superset, the physical locations of the voxels written in the subset can be different from the locations in the superset. For example, the first region 402 superset can be a sphere with a diameter of 18 micrometers, whose voxels are on a regular grid that has a period of 100 nanometers in each of the three directions, while the second region 404 subset can be a concentric sphere with a diameter of 15 micrometers, whose voxels are on a grid with the same period, but offset by 50 nanometers in one or more directions.

[0071] Figure 6 Shows another exemplary spherical optical component 600 having multiple step-index layers. The multiple step-index layers 601 to 605 can be used to approximate a Luneburg lens and / or other spherical lenses having a radially varying refractive index distribution. The multiple step-index layers 601 to 605 can be written in multiple sessions as different regions.

[0072] Cross Section Transition Bend

[0073] In various embodiments, it may be desirable to write a waveguide with bends within a porous scaffold. Additionally or alternatively, it may be desirable to transition from a first waveguide cross-section to a second waveguide cross-section. By way of illustration, a waveguide can be used to couple externally (into or out of the porous scaffold) in a first direction and then pass through a bend to route in another direction within the scaffold. The cross-section of the waveguide for coupling can be different from the cross-section for routing within the scaffold. Additionally or alternatively, the selected cross-sections that support writing the waveguide in the scaffold may vary based on the orientation of the waveguide. For example, if the waveguide is written parallel to the writing laser beam rather than perpendicular to the writing laser beam, the selected arrangement of voxels may be different. Additionally or alternatively, cross-section transitions can be used to achieve a bend with a specific bend radius while controlling the losses on the bend.

[0074] Figure 7 An exemplary porous scaffold 700 with an exemplary waveguide 710 is shown. The exemplary waveguide 710 includes a bend 712 having cross-sections 721 to 725 that transition from an elliptical cross-section 721 when the waveguide 710 is vertically oriented to a rectangular cross-section 725 when the waveguide is horizontally oriented. The intermediate cross-sections 722 to 724 show the gradual change of the cross-section from the elliptical cross-section 721 to the rectangular cross-section.

[0075] In the exemplary waveguide, the gradual change of the cross-section allows the function of the waveguide 710 to transition from supporting external coupling in the vertical direction to supporting in-scaffold routing in the horizontal direction. Additionally, the mode matching provided by the controlled cross-section gradual change allows the waveguide 710 to achieve a 90-degree bend with a selected bend radius 730 of the waveguide.

[0076] Figure 8 An exemplary bend logic 800 for determining a waveguide bend writing pattern is shown. For a first portion of the waveguide oriented to travel along a first axis, the bend logic 800 can obtain a first cross-section selection (802). For a second portion of the waveguide oriented to travel along a second axis, the bend logic 800 can obtain a second cross-section selection (803).

[0077] The bend logic 800 can determine a written bend such that the two portions are connected when writing the waveguide (804). The bend logic 800 can determine a set of transition cross-sections that map to the transformation from the first cross-section to the second cross-section (805). The logic 800 can determine the orientation of the set of transition cross-sections to transition the propagation of light in the waveguide between the first axis and the second axis (806).

[0078] Bending logic 800 may cause an optical writing system to write a first set of voxels (808) for a first portion of the waveguide that is consistent with a first cross-section. Bending logic 800 may cause the optical writing system to write a second set of voxels (810) for a second portion of the waveguide that is consistent with a second cross-section. Bending logic 800 may cause the optical writing system to write a third set of voxels (812) for a bend within the waveguide that is consistent with a determined transition cross-section.

[0079] In various embodiments, the first cross-section and the second cross-section may be determined by factors such as an internal waveguide structure, ease of waveguide writing, effective external coupling, and / or other factors. Thus, in some cases, bending logic 800 may obtain the first cross-section and / or the second cross-section by accessing a predetermined cross-section selection.

[0080] In various embodiments, the writing of the various portions of the waveguide may be performed in different orders. For example, the waveguide may be written from bottom to top, from top to bottom, in a mixture of both, and in various other directions. Thus, each of the first portion, the second portion, and / or the bend may be written in parallel, consecutively, or in multiple session portions. Thus, the writing order of the various portions of the waveguide may be independent of the planning / calculation order of the waveguide portions.

[0081] In addition to or as an alternative to considerations of the writing order, considerations of the writing quality may also affect the choice of the writing method for writing the waveguide. For example, various methods may be used to write the waveguide, such as using multi-session writing, multi-pass writing, dithering, transfer functions, multiple session writing, frame stitching, equal time between actuator movements, laser stability analysis, and / or other writing processes.

[0082] In various embodiments, multi-session writing and multi-pass writing may be used to smooth and / or enhance the refractive index contrast for the waveguide. Rewriting a written waveguide portion with an additional overlapping set of voxels may result in smoothing due to slight misalignment of multiple writing passes and / or an increase in contrast (e.g., relative to a scaffold background) due to increased crosslinking.

[0083] In various embodiments, various curves may be used. For example, a bend may be written such that the trajectory of the bend is a circular arc. For example, a bend may be written such that the trajectory of the bend is a Bezier curve. In some cases, a particular curve may be used to control losses within the waveguide bend, better adapt the bend to writing from a particular direction, better match the cross-section transition performed within the bend, and / or conform to other waveguide writing factors or constraints.

[0084] Figure 9An exemplary Bend Calculation Circuit (BCC) 900 for calculating the shape and / or orientation of a transition cross-section is shown. The BCC 900 can provide a hardware environment for the execution of the bend logic 800. The BCC 900 can include system logic 914 to support bend curve selection and / or calculation, cross-section analysis, transformation, and / or orientation calculation. The system logic 914 can include a processor 316, a memory 920, and / or other circuits that can be used to implement the exemplary bend logic 800.

[0085] The memory 920 can be used to store cross-section selections for various parts of different waveguides and / or bend curve profiles 924 (e.g., detailed angular gradients and size variations of various curves).

[0086] The memory 920 can further include applications and structures, such as encoded objects, templates, or one or more other data structures, to support iterative search operations. The BCC 900 can also include one or more communication interfaces 912, and the one or more communication interfaces 912 can support internal bus communication, wired / wireless data communication, and / or other operation inputs. The BCC 900 can include a power management circuit 934 and one or more input interfaces 928, and the one or more input interfaces 928 are for operator input and / or other operation controls.

[0087] The BCC 900 can be coupled to an optical writing system 999 for performing waveguide writing.

[0088] Adjusted Power Lookup

[0089] In various embodiments, based on the writing position of writable points within the writing field, the optical writing system can have a writing power variation. Thus, when writing with a uniform power / exposure time, although nominally writing with the same irradiation power and the same exposure time, the refractive indices of the voxels written in the writing field may be different.

[0090] Figure 10 A voxel array 1000 of an exemplary two-dimensional optical writing is shown. The illustrative voxel array 1000 of the exemplary two-dimensional optical writing is written with a uniform operating output power, where each voxel has a constant exposure time. Although the nominal output of the optical writing system is uniform, the voxel array 1000 of the exemplary two-dimensional optical writing exhibits non-uniformly written voxels. The voxels in one corner 1001 of the exemplary array 1000 have a lower density of cross-linking than the voxels in other parts 1002 to 1004 of the exemplary array 1000.

[0091] In various embodiments, the non-uniformity can depend on the power level. In other words, at different selected operating power levels, the non-uniformity of voxel writing in a given array may change. For example, there may be no non-uniformity at a first operating power level, but there may be non-uniformity at a different second operating power level. In various embodiments, in addition to the presence / absence differences, the pattern of non-uniformity may also change.

[0092] In some embodiments, an optical writing system can use an adjusted power data structure that includes correction entries for optical writing power. For example, an entry can include a scaling factor for adjusting the power level, which can indicate how much a particular power level (or exposure-power and duration) should be increased. An entry can include a corrected absolute power level. For example, for a particular selected effective power, an entry can include a corrected power. The corrected power can include an absolute power level rather than a scaling factor for the selected effective power. Thus, the adjusted power from the adjusted power data structure can include a scaling factor and / or an alternative absolute power level.

[0093] The adjustment of power can depend on the power. Thus, some systems can rely on the scaling factor for the adjustment entry, while other systems can use the power as a lookup input to allow for non-linear correction of the power level. The adjustment of power can depend on time. Thus, some systems may rely on power measurements at the time of writing and applying the scaling factor or lookup input to allow for time correction of the power level.

[0094] Entries can be written in a point - specific manner within the field. In other words, calibration entries can be dedicated to specific actuator coordinates of an optical writing system. For example, the write - in field can be defined by points accessible through the movement of one or more actuators. In some cases, the same type of actuator (e.g., motor - type, moving - type (rotational, angular, linear translation, or other movement), spot - focus - moving - type, mount - moving - type, and / or other types) can define the write - in field. When different types of actuators move, new write - in fields can be generated. Thus, the write - in field can include one - dimensional space (e.g., line, arc, or other curve), two - dimensional space (e.g., plane or other surface), volume, or multi - dimensional actuator space (as described below). As an example, the write - in field can include a two - dimensional plane generated by the movement of a linear translation actuator and a galvanometer, where the linear translation actuator translates the spot focus of the writing laser, and the galvanometer translates the spot focus of the writing laser by changing the angular deflection of a mirror. When a third actuator (e.g., z - axis translation) moves, the two - dimensional plane is translated to generate a new write - in field at the new z - axis position. Thus, in this illustrative example, the lookup input to the adjusted power data structure includes only two - dimensional plane actuator coordinates. In an alternative illustrative exemplary scenario, the z - axis position is additionally included in the lookup. In this alternative exemplary scenario, the write - in field is a volume rather than a plane.

[0095] In some cases, an optical system can use more than three actuators to move through a volume. In some cases, due to the type of actuator (e.g., galvanometer vs. linear stage, etc.), the entity moved by the actuator (spot - focus movement vs. mount movement), and the movement precision of the actuator, the power can depend on the actuator position rather than a specific point in space. In other words, a point in space can be accessed by multiple different combinations of actuator positions. Thus, more than three actuator position coordinates can be used to define the write - in field to create a multi - dimensional actuator space.

[0096] In some cases, the system can use multiple different write - in fields in parallel. For example, each of the multiple actuators can have a corresponding write - in field defined for that actuator. Thus, to determine the adjusted power, the system can perform multiple lookups, e.g., one lookup for each relevant write - in field.

[0097] In some cases, the adjusted power entries can be populated by determining a spatially varying optical transfer function (SOTF). The SOTF can be determined by performing one or more test write sessions to characterize the write field. A test write session can include writing voxels into a test substrate at selected points within the write field. In some cases, the selected points can include every point in the write field. In some cases, the selected points can include sampled points (e.g., spatially periodic sampling, random sampling, sampling clustered at locations of sharp change (gradient-related sampling), or other sampling selections). The test write session can be performed at one or more write power levels. After the test write session is complete, the written substrate is analyzed for spatial correlation regarding the contrast of the write. In some cases, the spatial correlation is determined by collecting fluorescence microscope images. The fluorescence intensity has a monotonic relationship with the density of the cross-linked polymer, and the density has an overall relationship with the refractive index. In some cases, the spatial correlation is determined by collecting bright-field, dark-field, confocal, or other forms of optical microscope images. The gray-scale intensity and / or color values of such images can have a monotonic relationship with the density of the cross-linked polymer and thus with the refractive index.

[0098] The spatial correlation of the test write sample field (e.g., captured within the test write substrate) can be inverted to determine the power adjustment amount that will result in spatially uniform writing at each test power level. A subsequent write session can be performed to achieve spatially uniform writing of an optical element such as a Fresnel biprism, from which the refractive index can be determined at a given adjusted power level. The power adjustment serves as the SOTF and can be used to populate the adjusted power data structure. This data structure can store the power necessary to obtain the desired refractive index at specific points within the write field. In cases where refractive index determination is not required or not performed, this data structure can store the power necessary to achieve the desired fluorescence, gray-scale, or color intensity at specific points within the write field. For systems characterized via sampled test write sessions, the unsampled points within the write field can be interpolated (alternatively, denoised via a neural AI model) to obtain the unsampled values.

[0099] The range of the tested power levels can be selected based on the choice of the optical component to be written by a particular optical write system. Thus, the range of power characterization can be matched to the (known or expected) operating range of the system under test.

[0100] Figure 11An exemplary Illumination Control Logic (ICL) 1100 is shown. The ICL 1100 may obtain instructions (1102) for an optical writing system to optically write voxels at selected points within a write field at a selected effective power. For example, the ICL 1100 may receive a set of optical writing instructions for an optical component within a stent. The instructions may include the position of the voxels and an indication of the exposure level (and / or the desired refractive index contrast level) of the voxels specified for writing by the set of instructions. The exposure level and / or the desired refractive index contrast level may be converted into a selected effective power for the system to perform optical writing (e.g., based on the power level characteristics of the system). Based on the relative positions with respect to various markers within the stent referenced at other positions of the stent, such as the off-plane distance, the distance from the edge, and / or other relative distances, the position of the voxels may be converted into points within the write field (e.g., actuator coordinates).

[0101] The ICL 1100 may access an adjusted power data structure to perform a lookup using the position within the write field and / or the selected effective power to determine an adjusted power (1104) that produces the selected effective power at the position within the write field. In response to the lookup, the adjusted power data structure may return an indication of the adjusted power to the ICL 1100 (1106). The ICL 1100 may then cause an optical write of the voxels at the selected points using a write illumination source set at the adjusted power (1108). For example, the ICL 1100 may generate adjusted optical writing instructions to replace the received instructions. The adjusted optical writing instructions may be sent to the optical writing system for execution. In some embodiments, the ICL 1100 may operate nested within the logic of the optical writing system and may determine the adjusted power in real time as the optical writing system receives and executes the writing instructions.

[0102] Figure 12 An exemplary Illumination Control Circuit (ICC) 1200 for irradiation power adjustment in an optical writing system is shown. The ICC 1200 may provide a hardware environment for the execution of the ICL 1100. The ICC 1200 may include system logic 1214 to support power adjustment lookups, instruction conversions, and / or other operations that support adjustment lookups and instruction corrections. The system logic 1214 may include a processor 1216, a memory 1220, and / or other circuitry that may be used to implement the exemplary illumination control logic 1100.

[0103] The memory 1220 may be used to store an adjusted power data structure 1224, which may include entries for one or more points within the write field and / or one or more power levels.

[0104] The memory 1220 may further include applications and structures, such as encoded objects, templates, or one or more other data structures, to support power adjustment and / or illumination control. The ICC 1200 may also include one or more communication interfaces 1212, which may support internal bus communication, wired / wireless data communication, and / or other operational inputs. The ICC 1200 may include a power management circuit 1234 and one or more input interfaces 1228 for operator input and / or other operational controls.

[0105] The ICC 1200 may be coupled to an optical writing system 1290 for performing waveguide writing. The optical writing system 1290 may include one or more actuators 1292, which may control positions within the write field 1294. The optical writing system 1290 may further include an illumination source 1296, which may include a controllable power output device (or be paired with a controllable power output device if the controllable power output device is external to the illumination source 1296). The controllable power output may be used to implement the adjusted power instructions from the ICL 1100.

[0106] Multi-pass Optical Writing

[0107] Multi-pass optical writing may include optical writing that uses the same or slightly offset voxels in each of multiple writing passes to rewrite the same volume. Multi-pass writing may be different from multi-session optical writing, as in multi-session optical writing, at least some voxels are written to different volumes in each of the different sessions.

[0108] In various embodiments, optical writing of an optical component using a single write pass can generate an optical component having one or more features that, in some scenarios, may degrade the quality of the optical component relative to an optical component that does not have such features. For example, compared to an optical component generated via multiple passes of writing, a single write pass can produce an optical component with a relatively small refractive index contrast. In an example, a single write pass may result in more individually defined voxels that make up the optical component. The "roughness" resulting from the explicitly defined individual voxels may degrade the quality of the written optical component. Multiple passes of writing can include rewriting voxels that are interleaved with voxels from a first write pass to achieve inter-voxel smoothing and / or an increased refractive index contrast with a background porous scaffold. Thus, multiple passes can reduce or eliminate features that degrade the quality of the written optical component. In an example of a microring resonator, multiple passes of writing using the same voxels in each pass can increase the quality factor of the resonator because the bending loss is reduced due to the higher refractive index contrast. Additionally or alternatively, multiple passes of writing using different voxels within the same microring volume can also significantly increase the quality factor because, in addition to the bending loss being reduced due to the higher refractive index contrast, the propagation loss is also reduced due to smoother sidewalls.

[0109] Figure 13 Illustrates an exemplary Multiple Pass Optical Writing Logic (MOWL) 1300. The MOWL 1300 can cause an optical writing system to write a first voxel (1302) in a first pass over a write field. The MOWL 1300 can cause the optical writing system to write a second voxel (1304) that overlaps the first voxel in a second pass over the write field. The MOWL 1300 can repeat the pass to rewrite the first voxel until a selected number of passes are completed (1306).

[0110] In some embodiments, actuator dithering, a particular multi-pass technique, can provide inter-voxel smoothing and / or increased refractive index contrast provided by other multi-pass techniques, but can further provide smoothing that corrects for artifacts caused by actuator movement. In some embodiments, some such artifacts due to actuator movement may persist even after performing multi-pass writing (without actuator dithering). The persistence of the artifacts may be due to errors in actuator movement. As an illustrative example, a linear translation stage type actuator can have an incremental step size corresponding to a minimum translation distance and / or position resolution. In some cases, the increment may vary due to defects, such as defects from manufacturing tolerances, motor quality, defects, and / or device wear. In some cases, the errors due to such defects may be present in each pass of the stage. In other words, the error occurs each time the stage moves past the same portion of the stage travel. In another illustrative example, a piezoelectric type actuator may have position errors due to voltage noise, crystal defects, and / or other defects. In another illustrative example, a galvanometer type actuator can have position quantization that can prevent uniform continuous angular deflection and result in a stepped incremental movement, which can generate patterns within the voxels being written.

[0111] Dithering can include writing a first pass on a write field using a first actuator, moving using a second actuator, compensating (using the first actuator) such that the movement of the second actuator is nullified, and then performing a second pass on the write field using the first actuator. Thus, although the goal of the write is to overlap the voxels from the first pass, the second pass can be performed at a different portion of the travel of the first actuator. In other words, the write field is offset with respect to the travel of the first actuator. Because the voxels are rewritten using different portions of the travel of the first actuator, the movement errors of the first actuator can be averaged.

[0112] In some cases, the compensation can be performed by a third actuator, for example, to correct for movement errors caused by the second actuator. Additionally or alternatively, multiple actuators can be used to compensate for the movement of the second actuator. For example, the travel made by the second actuator can include a component orthogonal to the travel of the first actuator. Thus, in the presence of such an orthogonal component of movement, compensation by only the first actuator may not be feasible.

[0113] In some embodiments, different types of actuators can be utilized to perform the compensation to correct for artifacts that may be present in all actuators of a given type. However, in various embodiments, some or all of the compensation can be performed using actuators of the same type. Actuator compensation of the same type can correct for single-actuator specific artifacts, such as device defects and / or manufacturing variations.

[0114] Figure 14 FIG. 1400 shows an exemplary dithering logic 1400. The dithering logic 1400 may cause an optical writing system to write a first set of voxels (1402) in a first writing pass on a writing field using a first actuator. The dithering logic 1400 may cause a second actuator of the optical writing system to move (1404). The dithering logic 1400 may use an actuator other than the second actuator, such as the first actuator, to compensate for the movement (1406). The dithering logic 1400 may cause the optical writing system to write a second set of voxels that overlap (or are close to) the first set of voxels in a second pass on the writing field using the first actuator (1408).

[0115] Figure 15 FIG. 1500 shows an exemplary multi-pass circuit (MPC) 1500 for multi-pass writing using an optical writing system 1590. The MPC 1500 may provide a hardware environment for the execution of the MOWL 1300 and / or the dithering logic 1400. The MPC 1500 may include system logic 1514 to support multi-pass movement, multi-actuator control, movement compensation, and / or other operations to support multi-pass writing and / or dithering. The system logic 1514 may include a processor 1516, a memory 1520, and / or other circuitry that may be used to implement the exemplary MOWL 1300 and the exemplary dithering logic 1400.

[0116] The memory 1520 may be used to store an actuator instruction set 1524. The memory 1520 may further include applications and structures, such as encoded objects, templates, or one or more other data structures, to support multi-pass movement, multi-actuator control, movement compensation, and / or other operations to support multi-pass writing and / or dithering. The MPC 1500 may also include one or more communication interfaces 1512, and the one or more communication interfaces 1512 may support internal bus communication, wired / wireless data communication, and / or other operation inputs. The MPC 1500 may include a power management circuit 1534 and one or more input interfaces 1528, and the one or more input interfaces 1528 are for operator input and / or other operation controls.

[0117] The MPC 1500 may be coupled to the optical writing system 1590 for performing multi-pass writing. The optical writing system 1590 may include a first actuator 1591 and / or a second actuator 1592, and the first actuator 1591 and / or the second actuator 1592 may be used for multi-pass writing and / or dithering operations.

[0118] Constant scan step interval

[0119] In various systems, the time interval between writing voxels can affect the degree of polymerization. For example, the writing of a voxel can cause local heating, which affects the crosslinking process of nearby voxels written subsequently. In some cases, the writing of a voxel can change the local concentration of available reactants, thereby also affecting the crosslinking process of subsequent voxels.

[0120] In various systems, the time interval between movements performed by an actuator can affect the nature of the error in the movements performed by the actuator. For example, due to different stabilization conditions, state refreshes, discharge states, and / or other time-varying conditions, the actuator may have different behaviors for different inter-movement intervals. In some cases, when using a first inter-movement interval, the actuator can exhibit a range of errors, and when using a second inter-movement interval, the actuator can exhibit a different range of errors.

[0121] In some embodiments, the behavior of the crosslinking process and the behavior of the actuator can be stabilized by using a constant inter-movement interval for a single actuator used in an optical writing system. For example, for any particular actuator, the time between movements performed by that actuator can be constant for an optical writing task. The inter-movement interval for a particular actuator does not necessarily have to be the same as the inter-movement interval of any other actuator used in the writing task. For example, for a series of scan steps during a scan, a first actuator can scan the distance it travels along the "X" axis. Once the first actuator completes its scan, a second actuator can perform a single scan step along the "Y" axis. Then, the first actuator can scan in the reverse direction along the "X" axis in another series of scan steps, and when the first actuator is done, the second actuator performs a single "Y" scan step again. This process can continue until the second actuator completes its scan along the "Y" axis. Since there is a scan by the first actuator along the "X" axis between each scan step performed by the second actuator, the time between the scan steps performed by the second actuator is constant. By a similar adjustment of other actuators, such as a third actuator that the timing of the scan steps of the first actuator depends on for movement along the "Z" axis, the interval between the steps of the first actuator can similarly be kept constant.

[0122] In some embodiments, the time between scan steps of an actuator can be the same as the time between the last step of the actuator's current scan and the first step of the next scan. This can ensure that the time between any movements performed by the actuator is at a constant interval.

[0123] In some embodiments, the actuator can move in continuous, non-quantized constant movements to complete a scan. In other words, in some cases, the scan of the actuator can include a single scan step.

[0124] In some embodiments, the actuator can move via an angular or rotational stroke. Thus, although the illustrative examples above discussed XYZ stroke, the system of the actuator can use other coordinate frames, such as a cylindrical and / or spherical coordinate frame, to move.

[0125] Figure 16 An exemplary interval logic 1600 is shown. The interval logic 1600 can control the movement timing of one or more actuators. To control the timing, the interval logic 1600 can control the interval between the movements of a second actuator such that the second actuator performs a scanning step (1610) after the first actuator completes a scan. The interval logic 1600 can control the interval, but determines the interval between movements to account for the first actuator completing the longest scan to be used in a write task (1612). The interval logic 1600 can cause the second actuator to perform a scanning step as each interval elapses until the optical write task is complete (1614).

[0126] In some embodiments, the interval logic 1600 can couple the timing of one actuator to the operation of another actuator. For example, when the first actuator completes a scan and / or performs a predetermined number of scan steps equivalent to a scan, the interval logic 1600 can enforce the interval by triggering the second actuator to move.

[0127] In some embodiments, the interval logic 1600 can cause the first actuator to scan regions in the write field where no voxels are to be written to ensure that the scan of the first actuator extends across the entire interval. If the scan is completed early, the first actuator can go dormant until the interval of another actuator is complete, and the first actuator can be used again for writing. Thus, the timing between the last step of the current scan and the first step of the next scan can be different from other intervals between the scan steps of the first actuator. Scanning across the full scan stroke can prevent such timing differences between scans.

[0128] In some embodiments, to avoid writing voxels as the actuator being scanned passes through these regions and otherwise altering regions where no voxels are to be written, the irradiation power of the irradiation source can be set below the writing threshold. Various techniques can be used to adjust the incident irradiation power. For example, light from the irradiation source can be blocked, diverted, attenuated, or otherwise reduced. In some embodiments, the irradiation source can be turned off and / or the irradiation source can be moved out of the high-power operation mode (e.g., the amplifier can be turned off and / or the laser can be moved out of the mode-locked state). Other methods of reducing the irradiation power can be used. In some embodiments, as described below, the stability of the irradiation source can be increased after an initial "warm-up" period. In some cases, techniques for reducing the irradiation power that interfere with the "warm-up" state of the irradiation source can be avoided. For example, some laser sources that rely on warm-up for stable operation may not have to be turned off (or otherwise powered down) to keep the illumination below the writing threshold. In some cases, moving the laser out of the mode-locked state may have a similar interfering effect on the warm-up state of the laser. Thus, techniques for reducing that allow the laser to remain mode-locked can be used.

[0129] Figure 17 An exemplary Moving Interval Circuit (MIC) 1700 is shown that controls the movement intervals of actuators 1791, 1792 in an optical writing system 1790. The MIC 1700 can provide a hardware environment for the execution of interval logic 1600. The MIC 1700 can include system logic 1714 to support multi-actuator timing, interval determination, actuator triggering, and / or interval enforcement. The system logic 1714 can include a processor 1716, a memory 1720, and / or other circuitry that can be used to implement the exemplary interval logic 1600.

[0130] The memory 1620 can be used to store an actuator instruction set 1724. The memory 1720 can further include applications and structures, such as encoded objects, templates, or one or more other data structures, to support multi-actuator timing, interval determination, actuator triggering, and / or interval enforcement. The MIC 1700 can also include one or more communication interfaces 1712, and the one or more communication interfaces 1712 can support internal bus communication, wired / wireless data communication, and / or other operational inputs. The MIC 1700 can include a power management circuit 1734 and one or more input interfaces 1728 for operator input and / or other operational controls.

[0131] The MIC 1700 can be coupled to the optical writing system 1790 for controlling actuator interval timing. The optical writing system 1790 can include a plurality of actuators 1791, 1792, and the plurality of actuators 1791, 1792 can be operated such that the movement intervals of the actuators remain constant.

[0132] Position Correction Lookup

[0133] In various embodiments, movement consistency errors within an actuator scan range can cause a mismatch between the position where an actuator places a point on one side of the actuator scan and the position where the actuator places the same point on the other side of the scan. In some cases, when generating a multi-dimensional write field from the scan ranges of two or more actuators, the errors can stack. As a result, a point may be placed differently at one corner of a multi-dimensional write field than at another corner of the same multi-dimensional write field. Write fields can be written side-by-side to allow for an optical component that is larger (at least in one dimension) than the range of a single write field. However, side-by-side write fields may have mismatches because opposite corners may be placed next to opposite corners. Thus, without correction, the optical component may exhibit stitching artifacts at the boundaries between adjacent write fields. Additionally, in various embodiments, errors in movement can cause a mismatch between the positions where an actuator places points even within a single write field. Thus, without correction, the optical component may exhibit a loss of shape fidelity between its designed shape and its written shape.

[0134] In some embodiments, an object (vernier scale, concentric box, checkerboard pattern, rectangular array, elliptical array, line array, array of other shapes, or other marked object) can be written into a stent at different corners of a write field. In some embodiments, an object (vernier scale, concentric box, checkerboard pattern, rectangular array, elliptical array, line array, array of other shapes, or other marked object) can be written into the stent at a specified position within a write field. The written object can be analyzed, for example, via microscopy analysis to determine coordinate corrections for such stitching errors at each corner and loss of shape fidelity within the write field. Thus, the placement of points can be corrected by writing at a corrected position that takes into account the positioning error.

[0135] However, correction for stitching errors or for shape fidelity can result in a positioning error of the spacing type. For example, correcting the position by a few micrometers (or other unit of distance) can cause the distance between objects in adjacent write fields or within the same write field to be slightly closer (or slightly farther) than the distance indicated by their absolute coordinates. Thus, when applying stitching or shape fidelity correction, a second absolute distance correction can be applied. The absolute distance correction can be determined by measuring the distance between analysis correction marks in each corner of the write field made for correction of stitching errors and analysis correction marks in each position within the write field made for correction of the above-described shape fidelity errors.

[0136] When correcting the stitching error, correcting the absolute distance can correct the alignment between write fields and avoid errors in the absolute distance (e.g., correcting the error caused by alignment by slightly overlapping the coordinates of the write fields). When correcting the stitching error, it is important to correct the shape fidelity. For example, without shape fidelity correction, the movement of the actuator may have misaligned derivatives at different corners. In other words, the errors in the expected movement of adjacent write fields may point in different directions. Therefore, the waveguides spanning into different write fields may exhibit kinks. In a long write line, this deflection error can be observed as a slight bend in the waveguide. This deflection can be corrected by measuring the curvature in the concentric frame and / or the cursor markers. In some cases, an extension line or an array of marker objects at specific positions within the write field can be written to characterize this deflection error and its correlation with the position.

[0137] Figure 18 FIG. shows an illustrative exemplary set of written objects 1810 written across two write fields 1890, 1892 in a porous scaffold 1800. Two external waveguides 1802 and 1804 are coupled to the porous scaffold. The illustrative exemplary set of written objects 1810 includes a waveguide 1820 having a stitching error 1822, a waveguide 1830 having a corrected stitching error 1832 and an absolute distance error 1834, and a waveguide 1840 having a shape fidelity deflection error 1842 and a kink 1844. In the illustrative example, the two external waveguides 1812 and 1814 have a predetermined spacing that is greater than the range of the write field of the optical system used to create the written objects 1810. Thus, in some cases, the writing process may include stitching together two write fields to generate a writing device that can be coupled to the two external waveguides 1812, 1814.

[0138] Figure 19 FIG. shows an illustrative example set of analysis objects 1910 in a porous scaffold 1900. The analysis objects include a concentric frame 1920, a cursor scale 1930, and an extension line 1940. The stitching error can be characterized by analyzing the eccentricity 1922 in the concentric frame 1920 and / or the misalignment amount 1932 of the cursor scale 1930 at the hash marks of adjacent write fields. The absolute distance error can be measured by measuring the distances 1952 between objects in different regions of the write field and ensuring that the coordinates on the scaffold written after the initial correction of the stitching misalignment match each other. The movement derivatives of various actuators can be characterized by measuring the deflection 1942 in the extension line 1940. The shape fidelity can be characterized by measuring the eccentricity 1952 of individual circles within an array 1950 that is written with a uniform spacing.

[0139] A correction matrix can be generated based on the determined stitching error, absolute distance error, and shape fidelity error. In a preferred embodiment, an adjusted position data structure can be generated for fast lookup and implementation of the non-linear correction to be performed. The correction matrix or adjusted position data structure for the write field can ensure that all regions of the write field are transformed such that the voxels intended to be written at selected points in physical space are transformed into points adjusted to the exact positions in the "actuator movement" space. This can result in all regions of the write field being written in consistent physical space coordinates, such that adjacent write fields as well as individual write fields have physical space continuity.

[0140] In some cases, the adjusted position data structure can include a correction matrix instead of the stored transformation results. Thus, the lookup operation can include obtaining matrix values and applying the matrix to the selected position to generate the correspondingly position-adjusted point.

[0141] Figure 20 An exemplary position control logic 2000 is shown. The exemplary position control logic 2000 can determine to write a voxel (2002) at a selected point within a write field. The selected point can include a point specified in physical space (e.g., the coordinate system of the porous scaffold being written). However, the coordinate system of the write field can include the actuator movement space. Thus, the position control logic 2000 can transform the selected point in physical space into a position-adjusted point in the actuator movement space.

[0142] The exemplary position control logic 2000 can perform a lookup using the selected point to obtain the position-adjusted point (2004) of the write field. The position control logic 2000 can cause the optical writing system to write the voxel at the position-adjusted point of the write field instead of at the selected position (2006). Then, the resulting voxel can be appropriately located within the physical space of the porous scaffold.

[0143] Figure 21 An exemplary position control circuit (PCC) 2100 for correcting position errors due to actuator movement is shown. The PCC 2100 can provide a hardware environment for the execution of the position control logic 2000. The PCC 2100 can include a system logic 2114 to support position lookup, matrix transformation, actuator positioning, and / or data structure generation. The system logic 2114 can include a processor 2116, a memory 2120, and / or other circuits that can be used to implement the exemplary interval logic 2000.

[0144] The memory 2120 can be used to store the actuator instruction set 2124. The memory 2120 can further include applications and structures, such as encoded objects, templates, or one or more other data structures, to support position lookup, matrix transformation, actuator positioning, and / or data structure generation. The PCC 2100 can also include one or more communication interfaces 2112, and the one or more communication interfaces 2112 can support internal bus communication, wired / wireless data communication, and / or other operation inputs. The PCC 2100 can include a power management circuit 2134 and one or more input interfaces 2128, and the one or more input interfaces 2128 are for operator input and / or other operation controls.

[0145] The PCC 2100 can be coupled to an optical writing system 2190 for controlling actuator positioning. The optical writing system 2190 can include a plurality of actuators 2191, 2192, and the plurality of actuators 2191, 2192 can be operated such that the transformed actuator coordinates are used to generate voxels correctly positioned in physical space.

[0146] Seam Smoothing

[0147] In some embodiments, in addition to or as an alternative to position error, there may be seams at the write field boundary because for one write field, writing stops, while for another write field, writing starts at the boundary. In some embodiments, even if the position error is fully corrected, due to the difference in the time interval between writing adjacent voxels within a single write field and writing adjacent voxels across the boundary between two write fields, there may be seams at the write field boundary. Seams may cause losses, such as due to reflection, optical confinement loss, and / or other loss mechanisms. In some embodiments, multi-pass writing (e.g., using the MOWL 1300 and / or dither logic 1500) can be applied to correct the seams by using a third actuator to offset the write fields of another set of actuators and then performing additional writing passes. For example, via a dither process, continuously offsetting the write field boundary and performing additional writing passes smooths the seams. Writing passes from one side or both sides of the boundary can be used to correct the seams. For these passes, a reduced illuminance output from the illumination source of the optical writing system can be used such that the desired optical contrast of the optical components for writing is achieved after multiple passes rather than in a single pass.

[0148] Illumination Source Warm Up

[0149] In some embodiments, after an initial warm-up period, the illumination source can exhibit increased stability during the time period for an optical writing task. For example, when the illumination source has been in the "on" or "standby" state for hours, days, weeks (or, in some cases, longer), the writing fidelity of the optical writing system (e.g., the resulting quality of the written optical component) increases. Thus, in some embodiments, the illumination source can be allowed to warm up for at least a predetermined period before use.

[0150] In some embodiments, quality indication markers can be written to the porous scaffold to demonstrate, for example, that sufficient power stability has been achieved prior to writing, for quality assurance and / or before investing time in writing the optical component. For example, an array of voxels at different illumination power levels can be written. Figure 22 An exemplary porous scaffold with arrays of voxels 2201 to 2205, 2211 to 2219 written therein is shown. The first set of arrays 2201 to 2205 are organized in a row, showing a decreasing illumination power. In some embodiments, the middle array 2203 can be designed to be written at a power slightly higher than the writing threshold power of a properly stable system, while the array 2204 can be designed to be written at a power slightly lower than the writing threshold power of a properly stable system. When arrays 2201 and 2202 are fully visible, array 2203 is slightly visible, and arrays 2204 and 2205 are not visible, it can be determined that power stability has been achieved. The presence of array 2204 or 2205 or the absence of arrays 2201, 2202, or 2203 can indicate that the quality target for the optical component written within the porous scaffold has not been met.

[0151] Additionally or alternatively, the power of the illumination source can be adjusted, and the arrays 2201 to 2205 can be written to other locations within the write field or to an adjacent write field. This process can be repeated until the visibility criteria are met. This process enables the writing of the optical component to start in a shorter time than the entire warm-up period. To minimize the detrimental effects of illumination power offset when writing one or more optical components, the arrays 2201 to 2205 can be written and the visibility checked, and the necessary adjustment to the illumination power can be determined in real time. To minimize the effects of spatial variations in the illumination source, the arrays 2201 to 2205 can be written at specific locations within the write field, and the visibility measured to determine the power adjustment as a function of spatial position and as a function of the desired set power. The measured data can be stored in a visibility data structure.

[0152] Figure 23Exemplary visibility standard logic 2300 is shown. The exemplary visibility standard logic can enable an optical writing system to optically write a set or sets of quality indication marks (2302) into a writing field. The visibility standard logic 2300 can obtain a measure of the visibility of the set of indication marks (2304). The visibility standard logic 2300 can determine an adjustment to the irradiation power for writing subsequent voxels in response to the measured visibility data (2306). The visibility standard logic 2300 can store the adjustment data in a visibility data structure (2308).

[0153] The visibility data structure can be used as an adjusted power data structure together with the irradiation logic 1100. Thus, the irradiation logic 1100 can additionally or alternatively consider variations in the irradiation power determined via the visibility standard.

[0154] Referring again to Figure 22 , the second set of arrays 2211 to 2219 are organized in a 3×3 grid. Because the central array 2215 is concentric with the box formed by the outer boundaries of the other eight arrays, this organization can provide a concentric box. Thus, such a set of arrays 2211 to 2219 can be used for the characterization of position errors in addition to the characterization of irradiation source stability. In some embodiments, the quality indication marks can be inspected in situ by the optical writing system (e.g., using an optical inspection microscope), thereby allowing the irradiation source to remain in an "on" or "standby" state.

[0155] The various logics described above can be easily grouped and / or combined to control the operation of an optical writing system having multi-session writing capabilities, multi-pass writing capabilities, dithering capabilities, bend calculation capabilities, power adjustment capabilities, shape fidelity correction capabilities, and / or other functions described herein.

[0156] The methods, apparatuses, processes, and logics described above can be implemented in many different ways and in many different combinations of hardware and software. For example, all or portions of the embodiments in an embodiment can be a circuit including an instruction processor such as: a central processing unit (CPU), a microcontroller, or a microprocessor; an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA); or a circuit including discrete logic or other circuit components, including analog circuit components, digital circuit components, or both; or any combination thereof. As an example, the circuit can include discrete interconnected hardware components and / or can be implemented on a single integrated circuit die, distributed across multiple integrated circuit dies, or in a multi-chip module (MCM) of multiple integrated circuit dies in a common package.

[0157] The circuit may further include or access instructions executed by the circuit. The instructions may be embodied as signals and / or data streams, and / or may be stored in a tangible storage medium such as flash memory, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM) other than transient signals; or stored on a magnetic disk or optical disk such as a compact disc read-only memory (CDROM), a hard disk drive (HDD), or other magnetic or optical disks; or stored in or on another machine-readable medium. A product such as a computer program product may specifically include a storage medium and instructions stored in or on the medium, and when executed by a circuit in a device, the instructions may cause the device to implement any of the processes described above or shown in the drawings.

[0158] Embodiments may be distributed among multiple system components, such as multiple processors and memories, as a circuit, e.g., as a combination of hardware and / or hardware and software, optionally including multiple distributed processing systems. Parameters, databases, and other data structures may be stored and managed separately, may be incorporated into a single memory or database, may be organized logically and physically in many different ways, and may be implemented in many different ways, including as data structures such as linked lists, hash tables, arrays, records, objects, or implicit storage mechanisms. Programs may be parts (e.g., subroutines) in a single program, separate programs, distributed across several memories and processors, or implemented in many different ways, such as in a library such as a shared library (e.g., a dynamic link library (DLL)). For example, when executed by a circuit, a DLL may store instructions to perform any of the processes described above or shown in the drawings.

[0159] The present disclosure has been described with reference to specific examples, which are merely illustrative and not limiting of the present disclosure. Changes, additions, and / or deletions may be made to the examples without departing from the spirit and scope of the present disclosure. Various embodiments have been described, and various embodiments are possible. Table 1 includes various examples.

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[0181] The above description is given only for easy understanding and should not be construed as an unnecessary limitation according to it.

Claims

1. A device, comprising: A porous scaffold, characterized by a scaffold refractive index; An optically written optical component, embedded in the porous scaffold; And A coating, forming the surface of the porous scaffold, the coating comprising: A surface, characterized by a surface refractive index; And A transition region, characterized by a refractive index gradient that transitions between the surface refractive index and the scaffold refractive index.

2. The device according to claim 1, wherein The coating comprises a coating material that diffuses into the transition region to form the refractive index gradient.

3. The device according to claim 2, wherein, The refractive index gradient corresponds to the diffusion profile of the coating material generated by diffusing the coating material into the porous scaffold.

4. The apparatus according to claim 1, wherein The scaffold refractive index comprises a refractive index between the ambient refractive index and the refractive index of the scaffold material of the porous scaffold.

5. The device according to claim 1, wherein The surface refractive index comprises a refractive index that matches the refractive index of a semiconductor material and / or the refractive index of silica.

6. The apparatus according to claim 1, wherein, The coating comprises a coating material deposited onto the scaffold via a low temperature and / or room temperature deposition process.

7. The device according to claim 1, wherein, The coating comprises a combination of multiple materials to affect the refractive index gradient.

8. The apparatus according to claim 7, wherein, The multiple materials comprise multiple materials coated onto the porous scaffold in the form of layers.

9. The apparatus according to claim 8, wherein, The multiple materials comprise an optical fluid and / or a material deposited via a carrier gas.

10. The apparatus according to claim 8, wherein, Each of the multiple materials comprises a component of the SiNx system.

11. The apparatus according to claim 10, wherein, The component of the SiNx system is characterized by a refractive index gradient spanning from the refractive index of a semiconductor material to the refractive index of a coupled optical fiber material.

12. The device according to claim 1, wherein, The optically written optical component comprises a coupler to couple one or more fiber ports to one or more on-chip ports.

13. A method, comprising: For a porous scaffold characterized by a scaffold refractive index, comprising an optically written optical component embedded in the porous scaffold: Coating a coating, the coating being formed on the surface of the porous scaffold, the coating comprising: A surface, characterized by a surface refractive index; and A transition region, characterized by a refractive index gradient that transitions between the surface refractive index and the scaffold refractive index.

14. The method according to claim 13, wherein Coating the coating comprises diffusing the material of the coating into the porous scaffold.

15. The method according to claim 13, wherein Coating the coating comprises performing a layered deposition of the coating on the porous scaffold.

16. The method according to claim 13, wherein, Coating the coating comprises changing an electrochemical etching current density to change the pore size across the thickness of the coating.

17. The method according to claim 13, wherein, Coating the coating comprises changing the silicon content of the coating across the thickness of the coating.

18. A device, comprising: A porous scaffold; And A coating, forming the surface of the porous scaffold, the coating comprising: A surface, characterized by a surface refractive index; And A transition region, diffusing into the porous scaffold, the transition region being characterized by a refractive index gradient that transitions between the surface refractive index and the scaffold refractive index characterizing the internal volume of the porous scaffold.

19. The device according to claim 18, wherein, The porous scaffold comprises an optically written optical component embedded within the internal volume.

20. The apparatus according to claim 18, wherein, The refractive index gradient corresponds to the diffusion profile of the coating material generated by diffusing the coating material into the porous scaffold.

21. A device, comprising: An optically written waveguide, embedded in a porous scaffold; And An optically written coupler optical component, on and / or embedded within the porous support, the optically written coupler optical component being near an end of the optically written waveguide.

22. The apparatus according to claim 21, wherein, The coupler optical component includes a spherical optical component.

23. The device according to claim 22, wherein, The refractive index of the spherical optical component varies along the radius of the spherical optical component.

24. The device according to claim 23, wherein, The spherical optical component has the highest refractive index at the center of the spherical optical component.

25. The device according to claim 24, wherein, The refractive index of the spherical optical component varies along the radius of the spherical optical component by having a step refractive index change at points along the radius of the spherical optical component.

26. The apparatus according to claim 24, wherein, The spherical optical component includes a Luneburg lens.

27. The apparatus according to claim 21, wherein, The optically written waveguide includes a taper near an end of the coupler optical component.

28. The apparatus according to claim 21, wherein, The coupler optical component includes voxels written in at least two writing sessions, including: A superset writing session that covers a first exposure area; and A subset writing session that includes a second exposure area within the first exposure area, the first area including at least a third exposure area not within the second exposure area.

29. A method, comprising: Optically writing a coupler optical component for a waveguide within a porous support by: Performing a superset writing session that covers a first exposure area of the coupler optical component within the porous support; And Performing a subset writing session that includes a second exposure area within the first exposure area, the first area including at least a third exposure area not within the second exposure area, such that the second exposure area is exposed for voxel writing in both the superset writing session and the subset writing session.

30. The method according to claim 29, wherein, The method includes performing the superset writing session before the subset writing session.

31. The method according to claim 29, wherein The method includes performing the subset writing session before the superset writing session.

32. The method according to claim 29, wherein, The performing of the superset writing session and the performing of the subset writing session result in a step refractive index difference in the refractive index between a portion of the coupler optical component within the second area and a portion of the coupler optical component within the third area.

33. The method according to claim 32, wherein: The first exposure area includes a spherical area; The second exposure area includes a spherical area concentric with the first exposure area, the second exposure area being smaller than the first exposure area.

34. The method according to claim 29, further comprising one or more additional subset sessions having corresponding exposure areas within the second area to approximate a continuous refractive index change by successive step refractive index changes.

35. The method according to claim 34, wherein: All of the exposure areas are spherical and concentric; and The coupler includes a Luneburg lens approximated using multiple step refractive index transitions.

36. A method, comprising: Optically writing an optical component within a porous support by: Performing a first writing session that covers a first exposure area of the optical component within the porous support; And Performing a second writing session, the second writing session including a second exposure region, the first region including at least a third exposure region not within the second exposure region, such that at least a portion of the second exposure region is exposed in both the first writing session and the second writing session for voxel writing.

37. The method according to claim 36, wherein, The method includes completing the first writing session before initiating the second writing session.

38. The method according to claim 36, wherein, The second region is at least partially located outside the first region.

39. The method according to claim 36, wherein: The first writing session includes a superset session; and The second writing session includes a subset session.

40. The method according to claim 36, wherein, The optical component includes a waveguide, an end coupler, a lens, and / or an optical resonator.

41. A method, comprising: Obtaining a first selected cross-section of a first portion of a waveguide to be written into a porous scaffold, the first portion being aligned along a first axis; Obtaining a second selected cross-section of a second portion of the waveguide to be written into the porous scaffold, the aligned second portion being along a second axis different from the first axis; Determining a bend for connecting the first portion to the second portion; Based on the first selected cross-section and the second selected cross-section, determining a set of transition cross-sections mapping to a transformation from the first cross-section to the second cross-section; Determining a corresponding orientation for each of the individual cross-sections in the set of transition cross-sections to orient the transition cross-sections along the bend; And Optically writing a first set of voxels in the porous scaffold along the first axis and consistent with the first selected cross-section to write the first portion in the porous scaffold; Optically writing a second set of voxels in the porous scaffold along the second axis and consistent with the second selected cross-section to write the second portion in the scaffold; And Optically writing a third set of voxels between the first portion and the second portion, the third set of voxels being consistent with the bend, the set of transition cross-sections, and the corresponding orientations.

42. The method according to claim 41, wherein: The porous scaffold is configured to couple to an external waveguide from a face of the scaffold; Optically writing the first set of voxels along the first axis includes writing the first set of voxels along an axis perpendicular to the face of the scaffold; And Optically writing the second set of voxels along the second axis includes writing the second set of voxels along an axis parallel to the face of the scaffold.

43. The method according to claim 42, wherein, The external waveguide includes an optical fiber and / or a waveguide within a semiconductor wafer.

44. The method according to claim 41, wherein: The porous scaffold is configured to couple to an external waveguide from a face of the scaffold; Optically writing the first set of voxels along the first axis includes writing the first set of voxels along an axis parallel to the face of the scaffold; And Optically writing the second set of voxels along the second axis includes writing the second set of voxels along an axis parallel to the face of the scaffold.

45. The method according to claim 41, wherein, The trajectory of the bend is a circular arc.

46. The method according to claim 41, wherein, The trajectory of the bend is a Bezier curve.

47. The method according to claim 41, wherein The trajectory of the bend is a 90-degree turn.

48. The method according to claim 41, wherein: The cross-section of the first selection includes a rectangular cross-section and / or an elliptical cross-section; and The cross-section of the second selection includes a rectangular cross-section and / or an elliptical cross-section.

49. The method according to claim 41, wherein, Writing the first set of voxels further includes an optical writing end coupler that is spaced from the end of the first portion and opposite the end of the first portion that is connected to the third set of voxels.

50. A waveguide optically written into a porous scaffold, the waveguide comprising: A first portion having a first selected cross-section, the first portion being aligned along a first axis within the porous scaffold; A second portion having a first selected cross-section, the second portion being aligned along a second axis within the porous scaffold, the second axis being different from the first axis; And A bend coupling the first portion to the second portion, the bend being characterized by a set of transition cross-sections that map to a transformation from the first cross-section to the second cross-section.

51. The waveguide according to claim 50, wherein: The porous scaffold is configured to couple to an external waveguide from a face of the scaffold; The first axis includes an axis perpendicular to the face of the scaffold; and The second axis includes an axis parallel to the face of the scaffold.

52. The waveguide according to claim 51, wherein, The external waveguide includes an optical fiber and / or a waveguide within a semiconductor wafer.

53. The waveguide according to claim 50, wherein, The trajectory of the bend is an arc.

54. The waveguide according to claim 50, wherein, The trajectory of the bend is a Bézier curve.

55. The waveguide according to claim 50, wherein, The trajectory of the bend is a 90-degree turn.

56. The waveguide according to claim 50, wherein: The first selected cross-section includes a rectangular cross-section and / or an elliptical cross-section; and The second selected cross-section includes a rectangular cross-section and / or an elliptical cross-section.

57. The waveguide according to claim 50, wherein, The porous scaffold further includes an end coupler that is spaced from the end of the first portion and opposite the end of the first portion that is connected to the bend.

58. A method, comprising: Optically writing a first set of voxels to generate a first-axis cross-section for writing a first portion of a waveguide, the first portion allowing light to propagate along a first axis within a porous scaffold; Determining to write a bend in the waveguide such that a second portion of the waveguide allows light to propagate along a second axis, the second axis being different from the first axis; Determining a second-axis cross-section corresponding to the second portion; Determining a set of transition cross-sections that map to a transformation from the first cross-section to the second cross-section; Determining the position of the starting point of the second portion; And Optically writing a second set of voxels into the porous scaffold to generate the set of transition cross-sections to form a bent portion of the waveguide between the end of the first portion of the waveguide and the starting point of the second portion of the waveguide.

59. The method according to claim 58, wherein: Optically writing along the first axis includes writing along an axis parallel to the propagation direction; and Optically writing the second axis includes writing along an axis perpendicular to the propagation direction.

60. The method according to claim 59, wherein: Generating the first-axis cross-section includes writing an elliptical cross-section that is transverse to the propagation direction of the writing laser; and Generating the second axis cross-section includes a write rectangular cross-section that is one voxel in height and parallel to the propagation direction of the write laser.

61. A method includes: Determining optically writing a voxel at a selected point within a write field at a selected effective power; Performing a lookup in an adjusted power data structure using the selected point and the selected effective power; In response to the lookup and obtaining an adjusted power from the adjusted power data structure, setting a write illumination source at the adjusted power to illuminate the selected point at the selected effective power; And Optically writing the voxel at the selected point using the write illumination source set at the adjusted power.

62. The method according to claim 61, wherein Optically writing the voxel includes optically writing the voxel in a porous scaffold at least partially within the write field.

63. The method according to claim 61, wherein, The adjusted power data structure includes a power adjustment entry for each of a set of points within the write field.

64. The method according to claim 63, wherein, The adjusted power data structure includes multiple power adjustment entries for each of the set of points within the write field, the multiple entries defining an adjustment scheme dependent on a power level.

65. The method according to claim 61, wherein, The write field includes points accessible via movement of a first actuator.

66. The method according to claim 65, wherein: Points accessible only via movement of an actuator other than the first actuator are outside the write field; and The write field includes a one-dimensional write field.

67. The method according to claim 65, wherein The write field includes points accessible via movement of a second actuator.

68. The method according to claim 67, wherein: Points accessible only via movement of an actuator other than the first actuator and the second actuator are outside the write field; and The write field includes a two-dimensional write field.

69. The method according to claim 65, wherein, The first actuator includes a piezoelectric actuator, a translation stage, a spot focus movement actuator, and / or a scaffold movement actuator.

70. The method according to claim 61, wherein Filling the adjusted power data structure using data generated by writing voxels at each point in the write field at a first test power.

71. The method according to claim 61, wherein, Filling the adjusted power data structure using data collected from an image, wherein the image includes a fluorescence intensity image, a bright field image, a dark field image, and / or a confocal image.

72. A system includes: An illumination source configured to illuminate a point within a write field; A memory configured to store an adjusted power data structure specific to the illumination source and the write field; An illumination control circuit configured to: Obtain an instruction to optically write a voxel at a selected point within the write field at a selected effective power; Using the selected point and the selected effective power, access the memory to perform a lookup in the adjusted power data structure; In response to the lookup, obtain an adjusted power, set the illumination source at the adjusted power to illuminate the selected point at the selected effective power; and When operating at the adjusted power, cause the illumination source to illuminate the selected point.

73. The system according to claim 72, wherein, The adjusted power data structure includes power adjustment entries for each of a set of points within the write field.

74. The system according to claim 73, wherein The adjusted power data structure includes multiple power adjustment entries for each of the set of points within the write field, the multiple entries defining an adjustment scheme that depends on a power level.

75. The system according to claim 72, wherein: The system further includes an actuator; and The write field includes points that are accessible via movement of the actuator.

76. The system according to claim 75, wherein, Determine the selected effective power based on a selected refractive index at which a voxel to be written will be located.

77. The system according to claim 72, wherein The illumination control circuit is further configured to access the memory to perform the lookup based on the actuator dwell time to determine an exposure associated with the selected effective power.

78. A product, comprising: A machine-readable medium other than an instantaneous signal; And Instructions stored on the machine-readable medium, the instructions being configured to, when executed, cause a processor to: Determine to optically write a voxel at a selected point within a write field at a selected effective power; Perform a lookup in an adjusted power data structure using the selected point and the selected effective power; In response to the lookup and obtaining an adjusted power from the adjusted power data structure, set a write illumination source at the adjusted power to illuminate the selected point at the selected effective power; And Cause the write illumination source to optically write the voxel at the selected point using the write illumination source set at the adjusted power.

79. The product according to claim 78, wherein, Fill the adjusted power data structure with data generated by writing voxels at each point in the write field at a first test power.

80. The product according to claim 79, wherein, Further fill the adjusted power data structure by repeating multiple test powers representative of a power range used in writing with various optical components.

81. A method, comprising: For an optical writing system having a first actuator of a first type and a second actuator of a second type, the second type being different from the first type: Determine to write a first set of voxels into a porous scaffold by performing a write pass on a write field using at least the first actuator; After completing the write pass on the write field, perform a movement using the second actuator; Compensate for the movement using an actuator other than the second actuator; And Perform a second write pass on the write field using at least the first actuator to write a second set of voxels that overlaps with the first set, the first set being written at a different position than when writing the second set using the second actuator.

82. The method according to claim 81, wherein: The first type includes an actuator type for moving a spot focus of the optical writing system; and The second type includes an actuator type for moving the porous scaffold.

83. The method according to claim 81, wherein, Compensating for the movement using an actuator other than the second actuator includes compensating for the movement using at least the first actuator.

84. The method according to claim 81, wherein, Compensating for the movement using an actuator other than the second actuator includes at least compensating for the movement using the first type of actuator.

85. The method according to claim 81, wherein: The movement offsets the position of the write field; and Compensating for the movement includes determining the offset position of the first voxel within the write field after the movement; and Performing the second write pass on the write field includes writing the second set of voxels at the offset position.

86. The method according to claim 81, wherein, The first set of voxels and the second set of voxels are different in position due to the positioning errors of the first actuator and / or the second actuator.

87. The method according to claim 81, wherein: The first type includes a piezoelectric actuator type; and The second type includes a galvanometer actuator type.

88. The method according to claim 81, wherein, The second write pass smooths the artifacts present in the first set of voxels caused by the movement errors of the first actuator and / or the second actuator.

89. The method according to claim 81, wherein, The first set of voxels forms: an end coupler, a waveguide, and / or a bend within the waveguide.

90. An optical writing system, comprising: A first actuator; A second actuator, different from the first actuator; And An actuator control circuit configured to: Perform a first write pass on a write field using at least the first actuator to write a first set of voxels into a porous scaffold; After completing the write pass on the write field, perform a movement using the second actuator; Compensate for the movement using an actuator other than the second actuator in the optical writing system; And Perform a second write pass on the write field using at least the first actuator to write a second set of voxels overlapping with the first set, the first set being written at a different position when writing the second set using the second actuator.

91. The optical writing system according to claim 90, wherein: The first type includes an actuator type for moving the spot focus of the optical writing system; and The second type includes an actuator type for moving the porous scaffold.

92. The optical writing system according to claim 90, wherein, The actuator control circuit is configured to compensate for the movement using at least the first actuator.

93. The optical writing system according to claim 90, wherein: The optical writing system further includes a third actuator having the first type; and The actuator control circuit is configured to compensate for the movement using at least the third actuator.

94. The optical writing system according to claim 90, wherein: The movement offsets the position of the write field; and The optical writing system is further configured to compensate for the movement by determining the offset position of the first voxel within the write field after the movement; and The optical writing system is further configured to perform the second write pass on the write field by writing the second set of voxels at the offset position.

95. The optical writing system according to claim 90, wherein, The first set of voxels and the second set of voxels are different in position due to the positioning errors of the first actuator and / or the second actuator.

96. The optical writing system according to claim 90, wherein: The first type includes a linear translation stage actuator type; and The second type includes a galvanometer actuator type.

97. A method includes: Determining to write a first set of voxels into a porous scaffold by performing a writing pass on a writing field using at least a first actuator; Performing a second writing pass on the writing field to write a second set of voxels that at least partially overlaps with the first set.

98. The method according to claim 97, wherein The second writing pass increases the refractive index contrast of at least a portion of an optical component written using the first set of voxels.

99. The method according to claim 98, wherein, The optical component includes an end coupler, a waveguide, and / or a bend in the waveguide.

100. The method according to claim 97, wherein, The second writing pass smooths artifacts present in the first set of voxels caused by movement errors of the first actuator and / or the second actuator.

101. A method includes: For a multi-actuator optical writing system: Controlling the interval between movements of a second actuator by performing a scan of a first actuator; Determining that no voxels are to be written into a portion of a write field covered by a continuation of the current scan of the first actuator; And Instead of stopping the current scan of the first actuator to immediately move the second actuator, continuing the current scan of the first actuator over a portion of the write field where no voxels are to be written to maintain the interval between movements for a constant duration.

102. The method according to claim 101, wherein, The period between scan steps of the first actuator is constant.

103. The method according to claim 102, wherein, Controlling the interval includes: Determining the number of scan steps used in traversing the full scan travel range of the first actuator; and Determining the interval based on the number and the period.

104. The method according to claim 102, wherein, The period is determined based on a target irradiation exposure level for voxel writing.

105. The method according to claim 102, wherein, The period is determined based on allowing a scan travel of a third actuator.

106. The method according to claim 101, further comprising setting the irradiation power from an irradiation source to be lower than a writing threshold when continuing the current scan of the first actuator over a portion of the write field where no voxels are to be written.

107. The method according to claim 106, wherein, Setting the irradiation power from the irradiation source to be lower than the writing threshold includes blocking irradiation from the irradiation source, diverting irradiation from the irradiation source, attenuating irradiation from the irradiation source, and / or turning off the irradiation source.

108. An optical writing system includes: A first actuator configured to perform multiple scans; A second actuator configured to perform scan steps after each of the multiple scans performed by the first actuator; And A control circuit configured to control the interval between scan steps of the second actuator by: Determining the interval that allows completion of the longest scan used in the writing task of the first actuator; and Causing the second actuator to wait for the entire interval between scan steps when the first actuator performs any scan for the writing task.

109. The optical writing system according to claim 108, wherein, The period between the scanning steps of the first actuator is constant.

110. The optical writing system according to claim 109, wherein, The control circuit is configured to determine the interval by: Determining the number of scanning steps used in traversing the full scanning stroke range of the first actuator; and Determining the interval based on the number and the period.

111. The optical writing system according to claim 109, wherein, The period is determined based on the target irradiation exposure level for voxel writing.

112. The optical writing system according to claim 109, wherein, The period is determined based on the scanning stroke allowed for the third actuator.

113. The optical writing system according to claim 108, wherein, The shortest scan performed by the first actuator is equal in duration to the longest scan.

114. The optical writing system according to claim 113, wherein, The first actuator is configured to continue the scan after completion of voxel writing for the scan to maintain a constant scan traversal period.

115. The optical writing system according to claim 114, wherein: The optical writing system further includes an irradiation source; and The control circuit is configured to set the irradiation power from the irradiation source to be lower than the writing threshold when there are no voxels to be written in the portion of the write field scanned by the second actuator.

116. The optical writing system according to claim 108, wherein, The first actuator is configured to perform the scan via non - quantized continuous movement.

117. A product, comprising: A machine - readable medium other than an instantaneous signal; And Instructions stored on the machine - readable medium, the instructions being configured to, when executed, cause a processor: For a multi - actuator optical writing system: Control the interval between the movements of the first actuator by performing a scan of the second actuator; Instead of stopping the current scan of the second actuator to accelerate the completion of the optical writing pass, continue the current scan of the second actuator over the portion of the write field where there are no voxels to be written to maintain the interval between movements at a constant duration.

118. The product according to claim 117, wherein, The period between the scanning steps of the first actuator is constant.

119. The product according to claim 118, wherein, The instructions are further configured to cause the processor to control the interval by: Determining the number of scanning steps used in traversing the full scanning stroke range of the first actuator; and Determining the interval based on the number and the period. The product according to claim 118, wherein, The period is determined based on the target irradiation exposure level for voxel writing.

121. A method, comprising: Determining to optically write a voxel at a selected point within a write field; Performing a lookup in an adjusted position data structure using the selected point; In response to the lookup from the adjusted position data structure, obtaining an adjusted - position point in the write field; And Optically writing the voxel at the adjusted - position point instead of the selected point.

122. The method according to claim 121, wherein, Filling the adjusted position data structure with data obtained by measuring relative position errors for different portions of the write field.

123. The method according to claim 121, wherein, Filling the adjusted position data structure with data obtained by measuring position variations that exist when writing the same voxel pattern for different combinations of actuator positions.

124. The method according to claim 121, wherein, Filling the adjusted position data structure with data obtained by: Measuring relative position differences of written objects at relative ranges of the write field; and / or Measuring distances between written objects at relative ranges of the write field; and / or Measure the relative position differences of written objects at specified locations across the area of the write field; and / or Measure the distances between written objects at specified locations across the area of the write field.

125. The method according to claim 121, wherein, Populate the adjusted position data structure with data obtained by:[[]] Attempting to write one or more sets of concentric nested boxes at different points in the write field; and Measuring the deviation from concentric alignment within the one or more sets.

126. The method according to claim 121, wherein, Populate the adjusted position data structure with data obtained by:[[]] Attempting to write one or more sets of cursor alignment marks at different points in the write field; and Using the cursor scale to measure the misalignment between different write field positions. The method according to claim 121, wherein, Populate the adjusted position data structure with data obtained by:[[]] Attempting to write one or more sets of measurement objects of a fixed shape at different points in the write field; Using the objects to measure the misalignment between different write field positions; and Measuring the shape fidelity of each object.

128. The method according to claim 121, wherein, The adjusted position data structure includes absolute distance correction to maintain continuity across the span of the write field.

129. The method according to claim 121, wherein, Populate the adjusted position data structure with data from microscopic analysis of optical writing on a porous scaffold.

130. The method according to claim 129, wherein: The microscopic analysis includes scanning electron microscope analysis; and The optical writing includes optical writing on the surface of the porous scaffold.

131. An optical writing system, comprising: An actuator configured to position the spot focus of the optical writing system; and A position control circuit configured to: Obtain an instruction to optically write a voxel at a selected point within a write field; Perform a lookup in the adjusted position data structure using the selected point; In response to the lookup in the adjusted position data structure, obtain the position-adjusted point in the write field; and Cause the actuator to position the spot focus at the position-adjusted point to write the voxel, rather than at the selected point.

132. The optical writing system according to claim 131, wherein, Populate the adjusted position data structure with data obtained by measuring relative position errors for different portions of the write field.

133. The optical writing system according to claim 131, wherein, Populate the adjusted position data structure with data obtained by measuring the position variations that exist when writing the same voxel pattern for different combinations of actuator positions.

134. The optical writing system according to claim 131, wherein, Populate the adjusted position data structure with data obtained via:[[]] Measuring the relative position differences of written objects at relative extents of the write field; Measuring the distances between written objects at relative extents of the write field; Measuring the relative position differences of written objects at specified locations across the area of the write field; and / or Measuring the distances between written objects at specified locations across the area of the write field.

135. The optical writing system according to claim 131, wherein, Populate the adjusted position data structure with data obtained via:[[]] Attempting to write one or more sets of concentric nested boxes at different points in the write field; and / or Measuring the deviation from concentric alignment within the one or more sets.

136. A product, comprising: A machine-readable medium other than a transient signal; and Instructions stored on a machine-readable medium, the instructions being configured to cause a processor, when executed, to: Determine optical writing of voxels at selected points within a write field; Perform a lookup in an adjusted position data structure using the selected points; In response to the lookup from the adjusted position data structure, obtain adjusted points of positions within the write field; and And Cause an actuator of an optical writing system to move a spot focus of the optical writing system to the adjusted points of positions to optically write voxels at the adjusted points of positions instead of at the selected points.

137. The product according to claim 136, wherein, The adjusted position data structure is populated by: Attempting to write one or more sets of measurement objects of a fixed shape at different points within the write field; Using the objects to measure misalignment amounts between different write field positions; and And Measuring shape fidelity of each object.

138. The product according to claim 136, wherein, The adjusted position data structure includes absolute distance correction to maintain continuity across the write field span.

139. The product according to claim 136, wherein, Data from a microscopic analysis of optical writing on a porous scaffold is used to populate the adjusted position data structure.

140. The product according to claim 139, wherein: The microscopic analysis includes scanning electron microscope analysis; and The optical writing includes optical writing on a surface of the porous scaffold.

141. The product according to claim 139, wherein, The microscopic analysis is performed in situ by the optical writing system.

142. A method, comprising: Determining optical writing of one or more sets of quality indication markers within a write field; Measuring visibility of the set of indication markers; In response to the measured visibility data, obtaining a determination as to whether an irradiation source has been sufficiently stabilized to a desired irradiation power; and / or In response to the measured visibility data, obtaining an adjustment to the irradiation power for writing subsequent voxels.

143. The method according to claim 142, wherein, The visibility power data structure includes power adjustment entries for each of a set of points within the write field.

144. The method according to claim 142, wherein, The visibility power data structure includes multiple power adjustment entries for each of the set of points within the write field, the multiple entries defining an adjustment scheme dependent on power levels.

145. A system, comprising: An irradiation source configured to irradiate points within a write field; A memory configured to store a visibility data structure specific to the irradiation source; An irradiation control circuit configured to: Obtain instructions to optically write voxels at selected points within the write field at a selected power; Use the selected points and the selected power to access the memory to perform a lookup in the visibility power data structure; In response to the lookup, obtain an adjusted power and set the irradiation source to irradiate the selected points at the selected power at the adjusted power; and When operating at the adjusted power, cause the irradiation source to irradiate the selected points.

146. The system according to claim 145, wherein, The visibility data structure includes power adjustment entries for each of a set of points within the write field.

147. The system according to claim 145, wherein, The visibility data structure includes multiple power adjustment entries for each of the set of points within the write field, the multiple entries defining an adjustment scheme dependent on power levels.

148. A product, comprising: Machine-readable medium other than transient signals; and instructions stored on the machine-readable medium, the instructions being configured to, when executed, cause a processor to: determine to optically write a voxel at a selected point in a write field at a selected power; perform a lookup in a visibility data structure using the selected point and the selected power; in response to the lookup and obtaining an adjusted power from the visibility data structure, set a write illumination source to illuminate the selected point at the selected power at the adjusted power; and cause the write illumination source to optically write the voxel at the selected point using the write illumination source set at the adjusted power.

149. The product according to claim 148, wherein, Fill the visibility data structure with data generated by writing voxels at a first test power at each point in the write field.

150. The product according to claim 148, wherein, Further fill the visibility power data structure by repeating over a plurality of test powers representative of a range of powers used in writing with various optical components.

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