Structures and methods for high speed interconnection in photonic systems are described herein. In one embodiment, a photonic device is disclosed. The photonic device includes: a substrate; a plurality of metal layers on the substrate; a photonic material layer comprising graphene over the plurality of metal layers; and an optical routing layer comprising a waveguide on the photonic material layer.

An in-plane photonic device is provided for transmission of an optical signal across a gap, in particular an in-plane photonic device for use in a photonic integrated circuit with one or more in-plane crossings of electrical connections and photonic waveguides. One embodiment relates to an in-plane photonic device for use in a photonic integrated circuit with in-plane crossings of electrical connections and photonic waveguides, including: at least one input optical waveguide; and at least one output optical waveguide; wherein the at least one input optical waveguide and the at least one output optical waveguides are positioned such that a gap between them separates the input and the output optical waveguide(s), and wherein the input and the output optical waveguides are configured for optical mode matching across the gap, such that an optical signal can be transmitted from the input optical waveguide to the output optical waveguide across the gap.

A method for establishing optical coupling between spatially separated first and second planar waveguides includes arranging an optical interconnect on the first planar waveguide. The optical interconnect has first and second end portions and an intermediate portion. Each of the end portions has an inverse taper. The second planar waveguide is arranged on the optical interconnect so that the second planar waveguide overlaps with one of the inverse tapered end portions but not the other inverse tapered end portion to thereby enable an adiabatic transition of an optical signal from the first planar waveguide to the second planar waveguide via the optical interconnect. The first and second planar waveguides have different refractive indices at an operating wavelength and the optical interconnect have a higher refractive index at the operating wavelength than the refractive indices of a core of the first planar waveguide and a core of the second planar waveguide.

A heterogeneous semiconductor structure, including a first integrated circuit and a second integrated circuit, the second integrated circuit being a photonic integrated circuit. The heterogeneous semiconductor structure may be fabricated by bonding a multi-layer source die, in a flip-chip manner, to the first integrated circuit, removing the substrate of the source die, and fabricating one or more components on the source die, using etch and/or deposition processes, to form the second integrated circuit. The second integrated circuit may include components fabricated from cubic phase gallium nitride compounds, and configured to operate at wavelengths shorter than 450 nm.

Structures for an edge coupler and methods of forming a structure for an edge coupler. The structure includes a waveguide core over a dielectric layer, and a back-end-of-line stack over the waveguide core and the dielectric layer. The back-end-of-line stack includes an interlayer dielectric layer, a side edge, a first feature, a second feature, and a third feature laterally arranged between the first feature and the second feature. The first feature, the second feature, and the third feature are positioned on the interlayer dielectric layer adjacent to the side edge, and the third feature has an overlapping relationship with a tapered section of the waveguide core.

Photonic devices having a photonic waveguiding layer, and a cladding layer, disposed on the photonic waveguiding layer, and where the cladding section is a material comprising Scandium. The cladding layer may include a material comprising Al.sub.1-xSc.sub.xN material where 0<x≤0.45.

Photonic devices having a quantum well structure that includes a Group III-N material, and a Al.sub.1-xSc.sub.xN cladding layer disposed on the quantum well structure, where 0<x≤0.45, the Al.sub.1-xSc.sub.xN cladding layer having a lower refractive index than the index of refraction of the quantum well structure.

Disclosed herein are configurations and methods to produce very low loss waveguide structures, which can be single-layer or multi-layer. These waveguide structures can be used as a sensing component of a small-footprint integrated optical gyroscope. By using pure fused silica substrates as both top and bottom cladding around a SiN waveguide core, the propagation loss can be well below 0.1 db/meter. Low-loss waveguide-based gyro coils may be patterned in the shape of a spiral (circular or rectangular or any other shape), that may be distributed among one or more of vertical planes to increase the length of the optical path while avoiding the increased loss caused by intersecting waveguides in the state-of-the-art designs. Low-loss adiabatic tapers may be used for a coil formed in a single layer where an output waveguide crosses the turns of the spiraling coil.

A semiconductor structure includes a group III-V chiplet over a group IV substrate. A group IV optoelectronic device is situated in the group IV substrate. A patterned group III-V optoelectronic device is situated in the group III-V chiplet. A heating element is near the group IV optoelectronic device, or alternatively, near the patterned group III-V optoelectronic device. A dielectric layer is over the patterned group III-V optoelectronic device. A venting hole is in the dielectric layer in proximity of the heating element. A cavity is in the group IV substrate in proximity to the heating element.

In one embodiment, an apparatus includes a substrate, an oxide layer on the substrate, a silicon layer on the oxide layer, which includes a waveguide region and etched regions adjacent to the waveguide region, a germanium layer on the silicon layer and adjacent the waveguide region of the silicon layer, and a resistive element adjacent to the germanium layer to provide heat to the germanium layer in response to a current applied to the resistive element.