A semiconductor optical wave guide device is described in which a buried oxide layer (BOX) is capable of guiding light. Optical signals may be transmitted from one part of the semiconductor device to another, or with a point external to the semiconductor device, via the wave guide. In one example, an optical wave guide is provided including a core insulating layer encompassed by a clad insulating layer. The semiconductor device may contain an etched hole for guiding light to and from the core insulating layer from a transmitter or to a receiver.