Optical modulator utilizing wafer bonding technology. An embodiment of a method includes etching a silicon on insulator (SOI) wafer to produce a first part of a silicon waveguide structure on a first surface of the SOI wafer, and preparing a second wafer, the second wafer including a layer of crystalline silicon, the second wafer including a first surface of crystalline silicon. The method further includes bonding the first surface of the second wafer with a thin oxide to the first surface of the SOI wafer using a wafer bonding technique, wherein a second part of the silicon waveguide structure is etched in the layer of crystalline silicon.