Aspects of the present disclosure are directed to process flow to fabricate a waveguide structure with a silicon nitride core having atomic-level smooth sidewalls achieved by wet etching instead of the conventional dry etching process. A mask is pre-biased to account for lateral etching during the wet-etching steps.

Provided is an optical isolator including a semiconductor substrate, an optical attenuator and an optical amplifier aligned with each other on the semiconductor substrate, an input optical waveguide connected to the optical attenuator, and an output optical waveguide connected to the optical amplifier, wherein a gain of the optical amplifier decreases based on an intensity of light incident on the optical amplifier increasing, wherein a first input light incident on the optical attenuator through the input optical waveguide is output as a first output light through the output optical waveguide, and a second input light incident on the optical amplifier through the output optical waveguide is output as a second output light through the input optical waveguide, and wherein when an intensity of the first input light and an intensity of the second input light are equal, an intensity of the first output light is greater than an intensity of the second output light.

A method of making an optical fiber-based sensor includes providing an optical fiber, and providing a sensing or protection layer on a surface of the optical fiber by an atomic layer deposition (ALD) process.

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.

A method is described of manufacturing an optical sensing element for detecting a presence and/or determining a concentration of an analyte in a fluid medium, in particular in an aqueous medium. The optical sensing element includes an optical waveguide (e.g. an optical fiber) comprising an optically transparent material for guiding light through the sensing element along a flightpath. The optical sensing element further includes an inorganic coating for adsorbing the analyte from the fluid medium and an adhesion promotion layer formed between the optical waveguide and the inorganic coating. The adhesion promotion layer includes an adhesion promotion material for promoting adhesion of the inorganic material.

Photonic devices having Al.sub.1-xSc.sub.xN and Al.sub.yGa.sub.1-yN materials, where Al is Aluminum, Sc is Scandium, Ga is Gallium, and N is Nitrogen and where 0<x≤0.45 and 0≤y≤1.

According to the present invention, a semiconductor device includes a substrate comprising a front end face, a rear end face and side faces, a plurality of semiconductor lasers provided on the substrate, a forward optical multiplexer to multiplex forward output light of the plurality of semiconductor lasers and output the multiplexed light to the front end face, a backward optical multiplexer to multiplex backward output light of the plurality of semiconductor lasers and output the multiplexed light to the rear end face and a plurality of backward waveguides connected to an output section of the backward optical multiplexer, wherein the plurality of backward waveguides includes a main waveguide disposed at a center of the output section and a plurality of lateral waveguides disposed on both sides of the main waveguide to bend toward the side faces and output light from the side faces diagonally to the side faces.

A semiconductor device is provided. The semiconductor device includes a silicon nitride waveguide in a first dielectric layer over a substrate. The semiconductor device includes a semiconductor waveguide in a second dielectric layer over the first dielectric layer. The first dielectric layer including the silicon nitride waveguide is between the second dielectric layer including the semiconductor waveguide and the substrate.

A device may include a first substrate. The device may include an optical source. The optical source may generate light when a voltage or current is applied to the optical source. The optical source may be being provided on a first region of the first substrate. The device may include a second substrate. A second region of the second substrate may form a cavity with the first region of the first substrate. The optical source may extend into the cavity. The device may include an optical interconnect. The optical interconnect may be provided on or in the second substrate and outside the cavity. The optical interconnect may be configured to receive the light from the optical source.

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.