A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

A Group III-Nitride quantum well laser including a distributed Bragg reflector (DBR). In some embodiments, the DBR includes Scandium. In some embodiments, the DBR includes Al.sub.1-xSc.sub.xN, which may have 0<x≤0.45.

There is provided a method for fabricating a vertically tapered spot-size converter on a substrate, comprising: growing a waveguide core on the substrate; coating the waveguide core with a photoresist layer; placing a photomask having patterns at a negative focus offset point with respect to the photoresist layer, the patterns being defined by openings in the photomask, each opening having a cross-section comprising a region of constant width and at least one region of non-constant width, the non-constant width reducing in a direction extending away from the region of constant width; transferring the patterns of the photomask to the photoresist layer; providing the waveguide core with a vertically tapered profile, the vertically tapered profile being provided by the patterns of the photomask; growing a cladding layer over the waveguide core; and patterning and etching the cladding layer and the waveguide core, thereby defining the vertically tapered spot-size converter.

A method of fabricating a waveguide structure to form a solid-core waveguide from a waveguiding layer may include etching a fluid channel into the waveguiding layer, etching a first air-gap and a second air gap into the waveguiding layer, wherein etching the first and the second air-gaps creates a solid-core waveguide in the waveguiding layer between the first air-gap and the second air-gap. A method for fabricating a waveguide structure to form a solid-core waveguide may include forming a first trench, a second trench, and a third trench in a substrate layer, and depositing a waveguiding layer on the machined substrate layer, wherein depositing the waveguiding layer creates a hollow core of a fluid channel in a location corresponding to the first trench, and a solid-core waveguide portion in the waveguiding layer in a location corresponding to an area between the second trench and the third trench.

A method of fabricating a waveguide structure to form a solid-core waveguide from a waveguiding layer may include etching a fluid channel into the waveguiding layer, etching a first air-gap and a second air gap into the waveguiding layer, wherein etching the first and the second air-gaps creates a solid-core waveguide in the waveguiding layer between the first air-gap and the second air-gap. A method for fabricating a waveguide structure to form a solid-core waveguide may include forming a first trench, a second trench, and a third trench in a substrate layer, and depositing a waveguiding layer on the machined substrate layer, wherein depositing the waveguiding layer creates a hollow core of a fluid channel in a location corresponding to the first trench, and a solid-core waveguide portion in the waveguiding layer in a location corresponding to an area between the second trench and the third trench.

An optical waveguide (100) is disclosed, for guiding light in a photonic circuit comprising a layer of phase change material (101) for modulating the phase of the guided light. The phase change material (101) is switchable between at least a stable crystalline state and a stable amorphous state each with different refractive indexes. The phase change material (101) exhibits an extinction coefficient of less than 0.1 in both states for wavelengths greater than 1000 nm.

Structures for a wavelength division multiplexing filter and methods of fabricating a structure for a wavelength division multiplexing filter. The structure includes a first waveguide core having a first section and a second section. The first section and the second section have a first notched sidewall and a second notched sidewall opposite to the first notched sidewall. The structure further includes a second waveguide core positioned with a first offset in a first direction relative to the first section and the second section of the first waveguide core and with a second offset in a second direction relative to the first section and the second section of the first waveguide core. The second direction is transverse to the first direction.

A disclosed semiconductor photodetector includes a first semiconductor layer having a first refractive index and a first band gap; a second semiconductor layer formed on the first semiconductor layer, the second semiconductor layer having a second refractive index and a second band gap; a first electrode; and a second electrode. The second refractive index is greater than the first refractive index, and the second band gap is smaller than the first band gap. The first semiconductor layer includes a p-type first region, an n-type second region, and a non-conductive third region between the first region and the second region. The second semiconductor layer includes a p-type fourth region in ohmic contact with the first electrode, an n-type fifth region in ohmic contact with the second electrode, and a non-conductive sixth region between the fourth region and the fifth region.

A electronic method, includes receiving, by a graphene structure, a microwave signal. The electronic method further includes receiving, by the graphene structure, two optical signals. The electronic method further includes generating, by the graphene structure, an entanglement between two optical signals and the microwave signal. The electronic method includes teleporting an unknown coherent state based on the entanglement.

Examples disclosed herein relate to quantum-dot (QD) photonics. In accordance with some of the examples disclosed herein, a QD semiconductor optical amplifier (SOA) may include a silicon substrate and a QD layer above the silicon substrate. The QD layer may include an active gain region to amplify a lasing mode received from an optical signal generator. The QD layer may have a gain recovery time such that the active gain region amplifies the received lasing mode without pattern effects. A waveguide may be included in an upper silicon layer of the silicon substrate. The waveguide may include a mode converter to facilitate optical coupling of the received lasing mode between the QD layer and the waveguide.