Patent ID: 7251408

Claim:
An optoelectronic device on a substrate comprising a rib waveguide and a lateral PN diode, wherein the rib waveguide comprises: a slab of monocrystalline silicon formed on the substrate, and a rib formed on the slab of monocrystalline silicon, and wherein the lateral PN diode comprises: first and second doped regions formed in the slab of monocrystalline silicon, where the second doped region is oppositely charged to the first doped region, first and second electrical contacts formed in the respective first and second doped regions in the slab of monocrystalline silicon, where a PN junction is formed at the boundary of the first and second doped regions and the PN junction is substantially in the center of a guided optical mode propagating through the rib waveguide, the concentration of dopant within each of the respective first and second doped regions is not uniform, the doping profile within each of the respective first and second doped regions is substantially non-linear, the highest concentration of dopant within each of the respective first and second doped regions is substantially adjacent to the first and second electrical contacts, and the lowest concentration of dopant within each of the respective first and second doped regions is substantially in the center of an optical mode propagating through the rib waveguide.