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: 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.