Abstract: Structures for a waveguide core and methods of forming such structures. The structure comprises a stacked waveguide core including a first waveguide core and a second waveguide core stacked with the first waveguide core, and a layer adjacent to the stacked waveguide core. The layer comprises a material having a refractive index that is variable in response to a stimulus.

Abstract: Structures for a waveguide core and methods of forming such structures. The structure comprises a stacked waveguide core including a first waveguide core and a second waveguide core stacked with the first waveguide core, and a layer adjacent to the stacked waveguide core. The layer comprises a material having a refractive index that is variable in response to a stimulus.

Abstract: Structures for an edge coupler of a photonics chip and methods of forming an edge coupler for a photonics chip. The structure includes a waveguide core on a dielectric layer, as well as an interconnect structure including a interlayer dielectric layer positioned over the dielectric layer and an opening penetrating through the interlayer dielectric layer to the waveguide core. A region of the interlayer dielectric layer is positioned to overlap with a portion of the waveguide core. The region of the interlayer dielectric layer has a surface that is rounded with a curvature.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to waveguide attenuators and methods of manufacture. The structure includes: a main bus waveguide structure; a first hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a first geometry of material; and a second hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a second geometry of the material.

Abstract: Structures for an optical power modulator and methods of fabricating a structure for an optical power modulator. A first waveguide core includes first and second sections. A second waveguide core includes a first section laterally adjacent to the first section of the first waveguide core and a second section laterally adjacent to the second section of the first waveguide core. An interconnect structure is formed over the first waveguide core and the second waveguide core. The interconnect structure includes first and second transmission lines. The first transmission line is physically connected within the interconnect structure to the first section of the first waveguide core. The second transmission line includes a first section physically connected within the interconnect structure to the second section of the first waveguide core and a second section adjacent to the first transmission line.

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 for a photodetector or terminator and methods of fabricating a structure for a photodetector or terminator. The structure includes a waveguide core having a longitudinal axis, a pad connected to the waveguide core, and a light-absorbing layer on the pad adjacent to the waveguide core. The light-absorbing layer includes an annular portion, a first taper, and a second taper laterally spaced from the first taper. The first taper and the second taper are positioned adjacent to the waveguide core.

Abstract: Structures for a photodetector and methods of fabricating a structure for a photodetector. A photodetector includes a photodetector pad coupled to a waveguide core and a light-absorbing layer coupled to the photodetector pad. The light-absorbing layer has a body, a first taper that projects laterally from the body toward the waveguide core, and a second taper that projects laterally from the body toward the waveguide core. The photodetector pad includes a tapered section that is laterally positioned between the first taper and the second taper of the light-absorbing layer.

Abstract: Structures for a photodetector or terminator and methods of fabricating a structure for a photodetector or terminator. The structure includes a waveguide core, a light-absorbing layer having a sidewall, and a taper positioned adjacent to the sidewall of the light-absorbing layer. The taper extends laterally from the sidewall of the light-absorbing layer to overlap with the waveguide core, and the taper has a thickness that varies with position relative to the sidewall of the light-absorbing layer. For example, the thickness of the taper may decrease with increasing distance from the sidewall of the light-absorbing layer.

Abstract: Structures for an edge coupler of a photonics chip and methods of forming an edge coupler for a photonics chip. The structure includes a waveguide core on a dielectric layer, as well as an interconnect structure including a interlayer dielectric layer positioned over the dielectric layer and an opening penetrating through the interlayer dielectric layer to the waveguide core. A region of the interlayer dielectric layer is positioned to overlap with a portion of the waveguide core. The region of the interlayer dielectric layer has a surface that is rounded with a curvature.

Abstract: Structures for a photodetector or terminator and methods of fabricating a structure for a photodetector or terminator. The structure includes a waveguide core having a longitudinal axis, a pad connected to the waveguide core, and a light-absorbing layer on the pad adjacent to the waveguide core. The light-absorbing layer includes an annular portion, a first taper, and a second taper laterally spaced from the first taper. The first taper and the second taper are positioned adjacent to the waveguide core.

Abstract: Structures for a photodetector or light absorber and methods of forming a structure for a photodetector or light absorber. The structure includes a pad, a waveguide core adjoined to the pad, and a light-absorbing layer on the pad. The waveguide core includes a first longitudinal axis, and the light-absorbing layer includes a second longitudinal axis and an end surface intersected by the second longitudinal axis. The end surface of the light-absorbing layer is positioned adjacent to the waveguide core. The first longitudinal axis of the first waveguide core is inclined relative to the second longitudinal axis of the light-absorbing layer and/or the end surface slanted relative to the second longitudinal axis.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to waveguide attenuators and methods of manufacture. The structure includes: a main bus waveguide structure; a first hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a first geometry of material; and a second hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a second geometry of the material.

Abstract: Structures for a wavelength-division multiplexing filter and methods of forming a structure for a wavelength-division multiplexing filter. The structure includes a first slab having a first perimeter, a first waveguide core coupled to the first slab, and a plurality of second waveguide cores coupled to the first slab. A second slab is positioned to overlap with the first slab. The second slab includes a second perimeter and openings that are distributed inside the second perimeter. The openings of the second slab penetrate through the second slab.

Abstract: Structures for an optical power modulator and methods of fabricating a structure for an optical power modulator. A first waveguide core includes first and second sections. A second waveguide core includes a first section laterally adjacent to the first section of the first waveguide core and a second section laterally adjacent to the second section of the first waveguide core. An interconnect structure is formed over the first waveguide core and the second waveguide core. The interconnect structure includes first and second transmission lines. The first transmission line is physically connected within the interconnect structure to the first section of the first waveguide core. The second transmission line includes a first section physically connected within the interconnect structure to the second section of the first waveguide core and a second section adjacent to the first transmission line.

Abstract: Structures for a wavelength-division multiplexing filter and methods of forming a structure for a wavelength-division multiplexing filter. The structure includes a first slab having a first perimeter, a first waveguide core coupled to the first slab, and a plurality of second waveguide cores coupled to the first slab. A second slab is positioned to overlap with the first slab. The second slab includes a second perimeter and openings that are distributed inside the second perimeter. The openings of the second slab penetrate through the second slab.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to waveguide attenuators and methods of manufacture. The structure includes: a main bus waveguide structure; a first hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a first geometry of material; and a second hybrid waveguide structure evanescently coupled to the main bus waveguide structure and comprising a second geometry of the material.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to multi-mode optical waveguide structures with isolated absorbers and methods of manufacture. The structure includes: a waveguide structure including tapered segments; and at least one isolated waveguide absorber adjacent to the waveguide structure along its length.

Abstract: The present disclosure relates to semiconductor structures and, more particularly, to multi-mode optical waveguide structures with isolated absorbers and methods of manufacture. The structure includes: a waveguide structure including tapered segments; and at least one isolated waveguide absorber adjacent to the waveguide structure along its length.

Abstract: Structures for a photodetector and methods of fabricating a structure for a photodetector. A photodetector includes a photodetector pad coupled to a waveguide core and a light-absorbing layer coupled to the photodetector pad. The light-absorbing layer has a body, a first taper that projects laterally from the body toward the waveguide core, and a second taper that projects laterally from the body toward the waveguide core. The photodetector pad includes a tapered section that is laterally positioned between the first taper and the second taper of the light-absorbing layer.