US-20260126583-A1 - VOLUMETRIC OPTICAL DEVICES

Abstract

A device includes a porous scaffold characterized by a scaffold refractive index. An optically written optic is embedded in the porous scaffold. A coating forms a surface of the porous scaffold. The coating includes the surface and a transition region. The surface is characterized by a surface refractive index. The transition region is characterized by a refractive index gradient that transitions between the surface refractive index and the scaffold refractive index

Inventors

• Lynford L. Goddard
• Paul V. Braun
• Alexander J. LITTLEFIELD
• Corey A. RICHARDS
• Christian H. Ocier
• Dajie Xie

Assignees

• THE BOARD OF TRUSTEES OF THE UNIVERSITY OF ILLINOIS

Dates

Publication Date

20260507

Application Date

20230929

Claims (20)

1. 1 . A device including: a porous scaffold characterized by a scaffold refractive index; an optically written optic embedded in the porous scaffold; and a coating forming a surface of the porous scaffold, the coating including: the 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. 2 . The device of claim 1 , where the coating includes a coating material, the coating material diffused into the transition region to form the refractive index gradient.
3. 3 . The device of claim 2 , where the refractive index gradient corresponds to a diffusion profile of the coating material generated by diffusing the coating material into the porous scaffold.
4. 4 . The device of claim 1 , where the scaffold refractive index includes a refractive index between an ambient refractive index and a refractive index of a scaffold material of the porous scaffold.
5. 5 . The device of claim 1 , where the surface refractive index includes a refractive index matched to a refractive index of a semiconductor material, and/or a refractive index of silica.
6. 6 . The device of claim 1 , where the coating includes a coating material deposited on to the scaffold via a low-temperature and/or room temperature deposition process.
7. 7 . The device of claim 1 , where the coating includes multiple materials in combination to effect the refractive index gradient.
8. 8 .- 11 . (canceled)
9. 12 . The device of claim 1 , where the optically written optic includes coupler to couple one or more fiber ports to one or more on-chip ports.
10. 13 .- 17 . (canceled)
11. 18 . A device including: a porous scaffold; and a coating forming a surface of the porous scaffold, the coating including: the surface characterized by a surface refractive index; and a transition region diffused into the porous scaffold, the transition region characterized by a refractive index gradient that transitions between the surface refractive index and a scaffold refractive index that characterizes an internal volume of the porous scaffold.
12. 19 .- 60 . (canceled)
13. 61 . A method including: determining to optically write a voxel at a selected point within a write field at a selected effective power; using the selected point and the selected effective power performing a lookup in an adjusted power data structure; obtaining, in response to the lookup and from the adjusted power data structure, an adjusted power at which to set a writing illumination source to illuminate the selected point at the selected effective power; and optically writing the voxel at the selected point with the writing illumination source set at the adjusted power.
14. 62 . The method of claim 61 , where optically writing the voxel includes optically writing the voxel in a porous scaffold positioned at least in part within the write field.
15. 63 . The method of claim 61 , where the adjusted power data structure includes a power adjustment entry for each of a set of points within the write field.
16. 64 . The method of claim 63 , where 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 a power-level dependent adjustment scheme.
17. 65 . The method of claim 61 , where the write field includes points accessible via motion of a first actuator.
18. 66 . The method of claim 65 , where: points accessible only through motion of actuators other than the first actuator are outside the write field; and the write field includes a one-dimensional write field.
19. 67 . The method of claim 65 , where the write field includes points accessible via motion of a second actuator.
20. 68 . The method of claim 67 , where: points accessible only through motion of actuators other than the first actuator and second actuator are outside the write field; and the write field includes a two-dimensional write field.

Description

PRIORITY This application claim priority to U.S. Provisional Application No. 63/412,107, filed Sep. 30, 2022, bearing attorney docket no. 010422-22001A-US, and titled Volumetric Optical Devices, which is incorporated by reference herein in its entirety. STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT This invention was made with government support under 1935289 awarded by the National Science Foundation. The government has certain rights in the invention. BACKGROUND Technical Field The disclosure relates generally to volumetric optical devices. Brief Description of Related Technology Rapid advances in communication technologies, driven by immense customer demand, have resulted in the widespread adoption of optical communication media. As one example, many millions of miles of optical fiber provide short and long haul optical communications throughout the world. Improved interconnects, optical processing, and integration with semiconductor based electronics will continue to increase demand. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example porous scaffold. FIG. 2 shows an example coating fabrication method. FIG. 3 shows an example porous scaffold. FIG. 4 shows an example multi-session optic. FIG. 5 shows an example multi-session optic writing method. FIG. 6 shows an example ball optic with multiple step-index layers. FIG. 7 shows an example porous scaffold with an example waveguide. FIG. 8 shows example bend logic. FIG. 9 shows example bend computation circuitry. FIG. 10 shows an example two-dimensional optically-written voxel array. FIG. 11 shows example illumination logic. FIG. 12 shows example illumination control circuitry. FIG. 13 shows example multi-pass optical writing logic. FIG. 14 shows example dither logic. FIG. 15 shows example multi-pass circuitry. FIG. 16 shows example interval logic. FIG. 17 shows example movement interval circuitry. FIG. 18 shows an illustrative example set of written objects. FIG. 19 shows an illustrative example set of analysis objects. FIG. 20 shows example position control logic. FIG. 21 shows example position control circuitry. FIG. 22 shows an example porous scaffold with multiple arrays of voxels written. FIG. 23 shows example visibility criteria logic. DETAILED DESCRIPTION In various contexts, volumetric integrated photonic devices may be integrated with other optical and/or photonic devices. Accordingly, methods and devices for improving integration, reducing insertion loss, and improving overall photonic device quality will improve performance and drive adoption of technologies. The various techniques and architectures discussed below provide for devices for coupling, free-space to guided-mode transitions, device writing with reduced writing artifacts and errors, waveguide bends, anti-reflective coating layers, and/or other volumetric integrated photonic device configurations and fabrication methods. In various systems optical interconnects, e.g., optical elements interfacing one or more optical mediums to one or more other media (including other optical media), utilize specific three-dimensional forms to couple light among the media. Further, for complex and/or multiplexed routing and/or filtering, complex three-dimensional forms may be used. In some cases, processing operations on optical signals may use complex and/or specifically dimensioned forms. In addition, lensing may, in some cases, use two or three dimensional forms of a complex nature (e.g., as opposed to curved lenses or flat uncomplicated forms such as Fresnel lenses) which may be designed through computer modelling or empirical study. Such complex two- or three-dimensional forms may be impractical or impossible to create or to align accurately using standard lens manufacturing techniques alone. Accordingly, techniques and architectures that allow the creation of monolithically integrated optical devices, electro-optical devices, photonic elements, interconnects, waveguides, prisms, and/or other optics of arbitrary dimension, function, and form, such as those discussed below involving writing one or more voxels into a scaffold and/or writing an optic into such a scaffold, offer improvements over existing market based solutions. In some systems, when writing a form to a medium, lower parts of a form provide support for the upper parts of the form because the writable medium (e.g., a polymer in liquid or aqueous form) provided no physical rigidity unless hardened through exposure. Accordingly, the conventional wisdom was that when constructing via laser writing an optic (e.g., into a polymer medium), the form of the optic should be selected such that the lower portions of the form would support the upper portions. In some cases, the inclusion of a scaffold provides rigidity within the writable medium allowing forms without support from lower portions of the structure, which allows one to proceed with structure selection that may be contrary to the conventional wisdom. A scaffold m