Electrical contacts on top of waveguide structures for efficient optical modulation in silicon photonic devices

A quantum well device for intensity modulation comprising:

• a first doped semiconductor alloy layer grown on a semiconductor substrate;
• a quantum well structure comprising an undoped semiconductor alloy quantum well layer sandwiched between a second doped semiconductor alloy layer of a same material and a doping as the first doped semiconductor alloy layer and a third doped semiconductor alloy layer of the same material and opposite doping as the first doped semiconductor alloy layer, the second doped semiconductor alloy layer contacting the first doped semiconductor alloy layer and being on top of the first doped semiconductor alloy layer;
• and
• an electrical contact on top of the quantum well structure, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the quantum well structure and the electrical contact and lower than the optical refractive index of the doped semiconductor alloy layers,
• wherein when a voltage is applied across the second doped semiconductor alloy layer and the third doped semiconductor alloy layer, an electric field and an optical absorption inside the undoped semiconductor alloy quantum well layer are changed, thereby modulating field intensity passing through said undoped semiconductor alloy quantum well layer.

A communication link between processor cores comprising:

• a high-speed modulator comprising:
• a phase modulation waveguide structure comprising:
• one of a semiconductor and a semiconductor-on-insulator substrate;
• a doped semiconductor layer formed over the one of a semiconductor and a semiconductor-on-insulator substrate, said doped semiconductor layer comprising a waveguide rib protruding from a surface thereof not in contact with the one of a semiconductor and a semiconductor-on-insulator substrate;
• and
• an electrical contact on top of the waveguide rib, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the waveguide rib and the electrical contact and lower than the optical refractive index of the doped semiconductor layer,
• wherein during propagation of an optical mode within the waveguide structure, the electrical contact isolates the optical mode between the doped semiconductor layer and a metal electrode contact on top of said electrical contact.

A communication link between processor cores comprising:

• a high-speed modulator comprising:
• a quantum well device comprising:
• a first doped semiconductor alloy layer grown on a semiconductor substrate;
• a quantum well structure comprising an undoped semiconductor alloy quantum well layer sandwiched between a second doped semiconductor alloy layer of a same material and a doping as the first doped semiconductor alloy layer and a third doped semiconductor alloy layer of the same material and opposite doping as the first doped semiconductor alloy layer, the second doped semiconductor alloy layer contacting the first doped semiconductor alloy layer and being on top of the first doped semiconductor alloy layer;
• and
• an electrical contact on top of the quantum well structure, said electrical contact being formed of a material with an optical refractive index close to that of a surrounding oxide layer that surrounds the quantum well structure and the electrical contact and lower than the optical refractive index of the doped semiconductor alloy layers,
• wherein when a voltage is applied across the second doped semiconductor alloy layer and the third doped semiconductor alloy layer, an electric field and an optical absorption inside the undoped semiconductor alloy quantum well layer are changed, thereby modulating field intensity passing through said undoped semiconductor alloy quantum well layer.