Patent ID: 7013070

Claim:
An apparatus, comprising: a first optical waveguide disposed in a semiconductor substrate layer, the first optical waveguide including a first charge layer; a second optical waveguide disposed in the semiconductor substrate layer, the second optical waveguide including a second charge layer; an electrically insulating layer disposed between the first and second waveguides in a coupling region in the semiconductor substrate layer to isolate the first optical waveguide from the second optical waveguide to separate the first charge layer from the second charge layer, the first and second charge layers formed proximate to the insulating region; and modulated charge layers including the first and second charge layers in the semiconductor substrate layer of the first and second optical waveguides, respectively, separated by and proximate to the electrically insulating layer between the first and second optical waveguides in the coupling region to control an optical coupling strength between the first and second optical waveguides.