Techniques are provided for single edge coupling of chips with integrated waveguides. For example, a package structure includes a first chip with a first critical edge, and a second chip with a second critical edge. The first and second chips include integrated waveguides with end portions that terminate on the first and second critical edges. The second chip includes a signal reflection structure that is configured to reflect an optical signal propagating in one or more of the integrated waveguides of the second chip. The first and second chips are edge-coupled at the first and second critical edges such that the end portions of the integrated waveguides of the first and second chips are aligned to each other, and wherein all signal input/output between the first and second chips occurs at the single edge-coupled interface.

Techniques are provided for single edge coupling of chips with integrated waveguides. For example, a package structure includes a first chip with a first critical edge, and a second chip with a second critical edge. The first and second chips include integrated waveguides with end portions that terminate on the first and second critical edges. The second chip includes a signal reflection structure that is configured to reflect an optical signal propagating in one or more of the integrated waveguides of the second chip. The first and second chips are edge-coupled at the first and second critical edges such that the end portions of the integrated waveguides of the first and second chips are aligned to each other, and wherein all signal input/output between the first and second chips occurs at the single edge-coupled interface.

Optical integrated circuits are provided. An optical integrated circuit includes a substrate including a single crystalline semiconductor material. The optical integrated circuit includes an insulation region in a trench in the substrate. The optical integrated circuit includes a first core on the insulation region. The first core includes the single crystalline semiconductor material. Moreover, the optical integrated circuit includes a second core that is spaced apart from the first core. The second core includes a material having a refractive index that is lower than that of the first core.

Optical integrated circuits are provided. An optical integrated circuit includes a substrate including a single crystalline semiconductor material. The optical integrated circuit includes an insulation region in a trench in the substrate. The optical integrated circuit includes a first core on the insulation region. The first core includes the single crystalline semiconductor material. Moreover, the optical integrated circuit includes a second core that is spaced apart from the first core. The second core includes a material having a refractive index that is lower than that of the first core.

Structures for a grating coupler and methods of fabricating a structure for a grating coupler. A silicide layer is formed on a patterned section of a semiconductor layer. The grating structures of a grating coupler are formed over the silicide layer and the section of the semiconductor layer.

A method includes forming silicon waveguide sections in a first oxide layer over a substrate, the first oxide layer disposed on the substrate, forming a routing structure over the first oxide layer, the routing structure including one or more insulating layers and one or more conductive features in the one or more insulating layers, recessing regions of the routing structure, forming nitride waveguide sections in the recessed regions of the routing structure, wherein the nitride waveguide sections extend over the silicon waveguide sections, forming a second oxide layer over the nitride waveguide sections, and attaching semiconductor dies to the routing structure, the dies electrically connected to the conductive features.

A method includes forming silicon waveguide sections in a first oxide layer over a substrate, the first oxide layer disposed on the substrate, forming a routing structure over the first oxide layer, the routing structure including one or more insulating layers and one or more conductive features in the one or more insulating layers, recessing regions of the routing structure, forming nitride waveguide sections in the recessed regions of the routing structure, wherein the nitride waveguide sections extend over the silicon waveguide sections, forming a second oxide layer over the nitride waveguide sections, and attaching semiconductor dies to the routing structure, the dies electrically connected to the conductive features.

A planar optical waveguide based on two-dimensional grating includes an optical waveguide substrate which is a transparent plane-parallel plate, and a functional grating element which includes a two-dimensional grating having two grating directions with an angle of 60 in between. The two-dimensional grating is either protruded or recessed into the top surface of the optical waveguide substrate. The output image from a micro-projector can enter the optical waveguide and then gets projected to cover the entire area of the functional grating element, enabling a human eye to view the output image across a large eye-box.

A planar optical waveguide based on two-dimensional grating includes an optical waveguide substrate which is a transparent plane-parallel plate, and a functional grating element which includes a two-dimensional grating having two grating directions with an angle of 60 in between. The two-dimensional grating is either protruded or recessed into the top surface of the optical waveguide substrate. The output image from a micro-projector can enter the optical waveguide and then gets projected to cover the entire area of the functional grating element, enabling a human eye to view the output image across a large eye-box.

Structures for a waveguide and methods of fabricating a structure for a waveguide. A grating coupler is formed that has an arrangement of grating structures. A conformal layer is arranged over the plurality of grating structures. The conformal layer is composed of a tunable material having a refractive index that changes with an applied voltage.