Abstract: Structures including a photonics chip and a surface-mounted laser chip, and methods of forming same. The structure comprises a photonics chip including a surface, a laser chip including a light output and a body that are spaced from the surface of the photonics chip, a first adhesive between the body of the laser chip and the surface of the photonics chip, and a second adhesive between the body of the laser chip and the surface of the photonics chip. The light output is oriented toward the surface of the photonics chip, the first adhesive has a first thermal conductivity, the second adhesive has a second thermal conductivity that is less than the first thermal conductivity of the first adhesive, and the second adhesive is disposed in a light path between the light output of the laser chip and the surface of the photonics chip.

Abstract: Structures for an edge coupler and methods of fabricating a structure for an edge coupler. The structure comprises an edge coupler including a first waveguide core and a second waveguide core adjacent to the first waveguide core in a lateral direction. The first waveguide core includes a first section with a first thickness and a first plurality of segments projecting in a vertical direction from the first section. The second waveguide core includes a second section with a second thickness and a second plurality of segments projecting in the vertical direction from the second section.

Abstract: Structures including multiple photonics chips and methods of fabricating a structure including multiple photonics chips. The structure comprises a first chip including a first edge and a first plurality of optical couplers disposed at the first edge, and a second chip including a second edge adjacent to the first edge of the first chip and a second plurality of optical couplers. The second plurality of optical couplers are disposed at the second edge adjacent to the first plurality of optical couplers.

Abstract: Structures for an edge coupler and methods of forming such structures. The structure comprises a semiconductor substrate, a first waveguide core including a curved section and an end that terminates the curved section, and a second waveguide core including a section disposed adjacent to the curved section of the first waveguide core. The first waveguide core is positioned between the second waveguide core and the semiconductor substrate.

Abstract: Structures including a waveguide core and methods of fabricating a structure including a waveguide core. The structure comprises a photonics chip including a first chip region, a first waveguide core in the first chip region, a second chip region, and a second waveguide core in the second chip region. The first chip region adjoins the second chip region along a boundary, the first waveguide core includes a first tapered section and the second waveguide core includes a second tapered section adjacent to the first tapered section. The first tapered section has a first longitudinal axis aligned substantially parallel to the boundary, and the second tapered section has a second longitudinal axis aligned substantially parallel to the boundary.

Abstract: Structures for a waveguide escalator and methods of forming such structures. A structure comprises a first waveguide core, and a back-end-of-line stack including a first dielectric layer, a second dielectric layer on the first dielectric layer, an opening in the second dielectric layer, a second waveguide core including a section that overlaps with a section of the first waveguide core, and a plurality of third waveguide cores disposed between the section of the first waveguide core and the section of the second waveguide core. The plurality of third waveguide cores are positioned inside the opening in the second dielectric layer, the first dielectric layer comprises a first material with a first refractive index, and the second dielectric layer comprises a second material with a second refractive index different from the first refractive index.

Abstract: Structures for an optical power splitter and methods of forming a structure for an optical power splitter. The structure comprises a spiral waveguide core having an outer perimeter. The structure further comprises a plurality of waveguide cores. Each waveguide core has a section disposed adjacent to the outer perimeter of the spiral waveguide core.

Abstract: Disclosed is a structure including a polarization device with first and second waveguides. The first waveguide includes a core (e.g., a silicon nitride (SiN) core) suitable for high-power applications. The second waveguide includes: a primary core (e.g., another SiN core), which is positioned laterally adjacent to the core of the first waveguide and suitable for high-power applications, and secondary core(s) stacked vertically with the primary core to steer the optical mode and ensure that mode matching occurs between adjacent first and second coupling sections of the first and second waveguides, respectively, in order to achieve high-power splitter and/or combiner functions. Optionally, the primary and secondary cores of the second waveguide can be tapered at least within the second coupling section to increase the likelihood of mode matching.

Abstract: Structures for a directional coupler and methods of forming a structure for a directional coupler. The structure comprises a first waveguide core including a first plurality of segments, and a second waveguide core including a second plurality of segments disposed adjacent to the first plurality of segments in a coupling region. The structure further comprises a first cladding layer comprising a first material that has a first refractive index, and a second cladding layer comprising a second material that has a second refractive index different from the first refractive index. The first cladding layer adjoins a first sidewall of each of the first plurality of segments and a first sidewall of each of the second plurality of segments, and the second cladding layer adjoins a second sidewall of each of the first plurality of segments and a second sidewall of each of the second plurality of segments.

Abstract: Structures for an edge coupler and methods of fabricating such structures. The structure includes a substrate, a first waveguide core, and a second waveguide core positioned in a vertical direction between the first waveguide core and the substrate. The second waveguide core includes a taper and an inverse taper longitudinally positioned adjacent to the taper.

Abstract: Structures including an optical phase shifter and methods of forming a structure including an optical phase shifter. The structure comprises an optical phase shifter including a waveguide core having a first branch and a second branch laterally spaced from the first branch. The structure further comprises a thermoelectric device including a first plurality of pillars and a second plurality of pillars that alternate with the first plurality of pillars in a series circuit. The first plurality of pillars and the second plurality of pillars disposed adjacent to the first branch of the waveguide core, the first plurality of pillars comprises an n-type semiconductor material, and the second plurality of pillars comprises a p-type semiconductor material.

Abstract: Structures including an edge coupler and methods of forming such structures. The structure comprises a dielectric layer on a semiconductor substrate. The dielectric layer includes a cavity and an edge defining a boundary of the cavity. The structure further comprises an edge coupler including a waveguide core. The waveguide core includes a portion that extends past the edge of the dielectric layer and overhangs the cavity. The structure further comprises a heater positioned adjacent to the portion of the waveguide core. The heater is spaced by a gap from the portion of the waveguide core.

Abstract: 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.

Abstract: Structures including a photodetector and methods of forming a structure including a photodetector. The structure comprises a photodetector including a pad having a side edge and a light-absorbing layer disposed on the pad. The structure further comprises a waveguide core including a tapered section positioned adjacent to the side edge of the pad and the light-absorbing layer. The tapered section has a width dimension that decreases with decreasing distance from the side edge of the pad.

Abstract: Structures for an edge coupler and methods of forming a structure for an edge coupler. The structure comprises a substrate, a dielectric layer over the substrate, and a waveguide core over the substrate. The structure further comprises an airgap that extends at least partially through the dielectric layer and that surrounds a plurality of sides of a portion of the waveguide core.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to lateral phototransistors and methods of manufacture. The structure includes a lateral bipolar transistor; and a T-shaped photosensitive structure vertically above an intrinsic base of the lateral bipolar transistor.

Abstract: Structures for an optical component, such as an optical reflector or an Echelle grating, and methods of forming such structures. The structure comprises a first waveguide core positioned in a vertical direction over a semiconductor substrate. The first waveguide core includes a tapered section and a plurality of segments separated by a plurality of gaps. A second waveguide core, which is positioned in the vertical direction relative to the first waveguide core, includes a portion positioned adjacent to the first waveguide core.

Abstract: Structures including stacked photonics chips and methods of fabricating a structure including stacked photonics chips. The structure comprises a first chip including a first waveguide core, a ring resonator adjacent to a portion of the first waveguide core, and a first dielectric layer over the first waveguide core and the ring resonator. The first dielectric layer has a first surface. The structure further comprises a second chip including a second waveguide core and a second dielectric layer over the second waveguide core. The second dielectric layer has a second surface adjacent to the first surface of the first dielectric layer, and the second waveguide core is positioned adjacent to the ring resonator.

Abstract: Structures and methods implement an enlarged multilayer nitride waveguide. The structure may include an inter-level dielectric (ILD) layer over a substrate. A first enlarged multilayer nitride waveguide is positioned in the ILD layer in a region of the substrate. A second multilayer nitride waveguide may also be provided in the ILD layer. A lower cladding layer defines a lower surface of the nitride waveguide(s). The lower cladding layer has a lower refractive index than the nitride waveguide(s). Additional lower refractive index cladding layers can be provided on the upper surface and/or sidewalls of the nitride waveguide(s). The enlarged nitride waveguide may be implemented with other conventional silicon and nitride waveguides.

Abstract: 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.