Abstract: A waveguide photodetector for reducing retro-reflection and increasing bandwidth is provided. The waveguide photodetector includes a waveguide photodiode comprising: a main waveguide; an absorbing waveguide integrated with the main waveguide, one or more of the absorbing waveguide and the main waveguide having an optical axis; an n-doped semiconductor region along a first side of the absorbing waveguide; a p-doped semiconductor region along a second side of the absorbing waveguide, the second side opposite the first side; and an input facet at the absorbing waveguide, the input facet forming an acute angle with the optical axis, and an interior of the input facet angled towards the p-doped semiconductor region, such that light input to the input facet is refracted towards the p-doped semiconductor region.

Abstract: A waveguide photodetector comprises: a multimode waveguide region (MMI); an input port and plurality of output ports at opposite sides of the MMI; and for each output port: an absorbing waveguide integrated with the main waveguide, the absorbing waveguide having an optical axis; n-doped and p-doped semiconductor region along respective opposite sides of the absorbing waveguide; an input facet at the absorbing waveguide, the input facet forming an acute angle with the optical axis, and an interior of the input facet angled towards the p-doped semiconductor region or the n-doped semiconductor region, such that at least a portion of light impinging on the input facet is refracted towards the p-doped semiconductor region or the n-doped semiconductor region. A refractive-index-modifying region is located adjacent the input facet, which comprises a region of changed refractive index relative to the main waveguide, and configured to reflect light incident thereon toward the input facet.

Abstract: A waveguide photodetector for reducing retro-reflection and increasing bandwidth is provided. The waveguide photodetector comprises: a waveguide photodiode having: a main waveguide, an absorbing waveguide integrated with the main waveguide, and an input facet at the absorbing waveguide; and an input waveguide for transmitting light to the waveguide photodiode, an input angle between the input waveguide and the input facet comprising an acute interface angle.

Abstract: A photodiode includes an input waveguide, a photodiode component comprising a photodiode material, and an optical coupling waveguide. The input waveguide and the optical coupling waveguide are optically coupled to each other at respective ends external to the photodiode component. The optical coupling waveguide is positioned adjacent to the photodiode material along at least a portion of its length and is optically coupled to the photodiode material along at least part of that length. This configuration enables guided optical signals to be coupled from the input waveguide through the optical coupling waveguide and into the photodiode material for efficient photodetection.