Patent ID: 7447395

Claim:
A silicon-based optical modulating device formed in a silicon-on-insulator (SOI)-based structure including a silicon substrate. a buried oxide layer and a sub-micron thick silicon surface layer, the modulating device comprising an optical waveguide formed in the sub-micron thick silicon surface layer for supporting the propagation of an incoming lightwave signal; a modulating element disposed along the waveguide to introduce an electrical alternating current (AC) modulating signal into the optical waveguide and modify the properties of the propagating lightwave signal, the modulating element comprising a doped silicon layer disposed in an overlapped arrangement with an oppositely-doped portion of the sub-micron thick silicon surface layer; and a thermo-optic element disposed along the optical waveguide and responsive to an applied direct current (DC) voltage to generate heat that is transferred into the waveguide so as to modify the waveguide refractive index as a function of the change in temperature.