A multi-level semiconductor device, the device including: a first level including integrated circuits; a second level including a structure designed to conduct electromagnetic waves, where the second level is disposed above the first level, where the integrated circuits include single crystal transistors; and an oxide layer disposed between the first level and the second level, where the second level is bonded to the oxide layer, and where the bonded includes oxide to oxide bonds.

A device includes a first package connected to an interconnect substrate, wherein the interconnect substrate includes conductive routing; and a second package connected to the interconnect substrate, wherein the second package includes a photonic layer on a substrate, the photonic layer including a silicon waveguide coupled to a grating coupler and to a photodetector; a via extending through the substrate; an interconnect structure over the photonic layer, wherein the interconnect structure is connected to the photodetector and to the via; and an electronic die bonded to the interconnect structure, wherein the electronic die is connected to the interconnect structure.

A photonic structure is provided. The photonic structure includes a first oxide layer in a semiconductor substrate, a second oxide layer over an upper surface of the semiconductor substrate and an upper surface of the first oxide layer, and an optical coupling region over an upper surface of the second oxide layer. The optical coupling region is made of silicon, and an area of the optical coupling region is confined within an area of the first oxide layer in a plan view.

A waveguide is disclosed for use in an augmented reality or virtual reality display. The waveguide includes a plurality of optical structures exhibiting differences in refractive index from a surrounding waveguide medium. The optical structures are arranged in an array to provide at least two diffractive optical elements overlaid on one another in the waveguide. Each of the two diffractive optical elements is configured to receive light from an input direction and couple it towards the other diffractive optical element which can then act as an output diffractive optical element, providing outcoupled orders towards a viewer. The optical structures have a shape, when viewed in the plane of the waveguide, comprising a plurality of substantially straight sides having respective normal vectors at different angles and this can effectively reduce the amount of light that is coupled out of the waveguide on first interaction with the optical structures.

Disclosed are embodiments of a photonic integrated circuit (PIC) structure with a waveguide core having tapered sidewall liner(s) (e.g., symmetric tapered sidewall liners on opposing sides of a waveguide core, asymmetric tapered sidewall liners on opposing sides of a waveguide core, or a tapered sidewall liner on one side of a waveguide core). In some embodiments, the tapered sidewall liner(s) and waveguide core have different refractive indices. In an exemplary embodiment, the waveguide core is a first material (e.g., silicon) and the tapered sidewall liner(s) is/are a second material (e.g., silicon nitride) with a smaller refractive index than the first material. In another exemplary embodiment, the waveguide core is a first compound and the tapered sidewall liner(s) is/are a second compound with the same elements (e.g., silicon and nitrogen) as the first compound but with a smaller refractive index. Also disclosed are method embodiments for forming such a PIC structure.

A waveguide is disclosed for use in an augmented reality or virtual reality display. The waveguide includes a plurality of optical structures (10, 20, 30, 40, 50, 60, 70, 80) exhibiting differences in refractive index from a surrounding waveguide medium. The optical structures are arranged in an array to provide at least two diffractive optical elements (H1, H2) overlaid on one another in the waveguide. Each of the two diffractive optical elements is configured to receive light from an input direction and couple it towards the other diffractive optical element which can then act as an output diffractive optical element, providing outcoupled orders towards a viewer. The optical structures have a shape, when viewed in the plane of the waveguide, comprising a plurality of substantially straight sides having respective normal vectors at different angles and this can effectively reduce the amount of light that is coupled out of the waveguide on first interaction with the optical structures.

Examples described herein relate to an optical device having a photonic-crystal lattice structure. In some examples, the optical device may include a substrate having a photonic-crystal lattice structure. The optical device may further include an optical waveguide formed in the photonic-crystal lattice structure and a defect cavity formed in the photonic-crystal lattice structure and optically coupled to the optical waveguide. Furthermore, the optical device may include a refractive index tuning structure adjacent to the defect cavity in the photonic-crystal lattice structure.

The invention relates to a method for fabricating a semiconductor structure. The method comprises fabricating a photonic crystal structure of a first material, in particular a first semiconductor material and selectively removing the first material within a predefined part of the photonic crystal structure. The method further comprises replacing the first material within the predefined part of the photonic crystal structure with one or more second materials by selective epitaxy. The one or more second materials may be in particular semiconductor materials. The invention further relates to devices obtainable by such a method.

Systems, devices, and techniques for performing wavelength division multiplexing or demultiplexing using one or more metamaterials in an optical communications systems are described. An optical device may be configured to shift one or more phase profiles of an optical signal using one or more stages of metamaterials to multiplex or demultiplex wavelengths of optical signals. The optical device may be an example of a stacked design with two or more stages of metamaterials stacked on top of one another. The optical device may be an example of a folded design that reflects optical signals between different stages of metamaterials.

Photonic packages and device assemblies that include photonic integrated circuits (PICs) coupled to optical lenses on lateral sides of the PICs. An example photonic package comprises a package support, an integrated circuit (IC), an insulating material, a PIC having an active side and a lateral side substantially perpendicular to the active side. At least one optical structure is on the active side. A substantial portion of the active side is in contact with the insulating material, and the PIC is electrically coupled to the package support and to the IC. The photonic package further includes an optical lens coupled to the PIC on the lateral side. In some embodiments, the photonic package further includes an interposer between the PIC or the IC and the package support.