Patent ID: 8520985

Claim:
A Mach-Zehnder modulator, comprising: an input wave guide and an output wave guide arranged over a substrate; a first branch wave guide and a second branch wave guide coupled in parallel between the input and output wave guides; and a connecting region coupled to and disposed between the first branch wave guide and the second branch wave guide and doped with a first dopant; first doped regions disposed on first and second sides of the connecting region and doped with the first dopant; second doped regions disposed on the first and second sides of the connecting region and doped with a second dopant having a different conductivity from the first dopant; a first junction corresponding to a boundary of the first doped region disposed on the first side of the connecting region and the second doped region disposed on the first side of the connecting region; and a second junction corresponding to a boundary of the first doped region disposed on the second side of the connecting region and the second doped region disposed on the second side of the connecting region.