Patent ID: 7453132

Claim:
A waveguide photodetector comprising: a waveguide comprising: a core comprised of a germanium on silicon heterojunction stack comprising: a silicon layer comprising substantially silicon for conducting light, and a germanium layer comprising substantially germanium for conducting light; and a cladding comprised of a plurality of dielectric materials, a first plurality of conductive contacts coupled to said germanium layer, and a second plurality of conductive contacts coupled to said silicon layer, wherein the germanium on silicon heterojunction forms a diode structure with a depletion region, where the diode structure is capable of producing and separating electron hole pairs caused by photons absorbed in the depletion region, wherein the cladding further comprises: a bottom cladding, a side cladding and a top cladding, where each of the claddings is comprised of the plurality of dielectric materials, wherein at least a portion of a CMOS transistor and the silicon layer of the core of the waveguide are formed from a starting silicon layer, and wherein at least one conductive contact of the first and the second pluralities of conductive contacts is operatively coupled to the CMOS transistor.