Silicon-based integrated optical chip

Abstract

The present invention provides a silicon-based integrated optical chip integrating a silicon-based optical modulator and a germanium-silicon detector and a preparation method thereof. A position and dimension of a silicon nitride waveguide are defined by a slot formed by using an etching process, then surplus silicon nitride is removed by means of chemico-mechanical polishing, and an optical waveguide is formed by the silicon nitride in the slot. Therefore, the preparation of the silicon nitride waveguide according to the present invention can be compatible with a process for preparing the silicon-based integrated optical chip including the silicon-based optical modulator and the germanium-silicon detector, and a distance between the silicon nitride waveguide and the silicon waveguide may be controlled flexibly, so that controllable coupling strength and coupling loss between the silicon waveguide and the silicon nitride waveguide are implemented; and the silicon waveguide at a bottom layer and the silicon nitride waveguide at an upper layer may be used to design in combination various passive devices with better performance, for example, a coupler with lower coupling loss and a waveguide with lower transmission loss.