Patent ID: 7085443

Claim:
An optoelectronic device on a substrate comprising a silicon waveguide and a lateral PN diode, where the lateral PN diode comprises: first and second doped regions formed in a slab of semiconductor, 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 semiconductor, 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 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 waveguide.