Shielded photonic integrated circuit
A light shield may be formed in photonic integrated circuit between integrated optical devices of the photonic integrated circuit. The light shield may be built by using materials already present in the photonic integrated circuit, for example the light shield may include metal walls and doped semiconductor regions. Light-emitting or light-sensitive integrated optical devices or modules of a photonic integrated circuit may be constructed with light shields integrally built in.
1. A photonic integrated circuit comprising:
a substrate;
a first integrated optical device comprising a slab optical waveguide, a photosensitive slab extending from and optically coupled to the slab optical waveguide, and at least one input/output waveguide over the substrate; and
a metal, light-shield structure surrounding the photosensitive slab, extending from the slab optical waveguide higher than the photosensitive slab and capable of shielding the slab waveguide from stray light from adjacent optical devices;
wherein the metal, light-shield structure comprises a first electrode electrically coupled to the slab optical waveguide for conducting a photoelectric signal therefrom; and
a second electrode on top of the photosensitive slab for shielding the photosensitive slab from stray light.
2. The photonic integrated circuit according to claim 1 , further comprising a second integrated optical device over the substrate adjacent to the first integrated optical device with the metal, light-shield structure therebetween.