Double-color waveguide photoelectric detector and preparation method thereof

The invention provides a two-color waveguide photoelectric detector. The two-color waveguide photoelectric detector comprises an SOI substrate; the SOI substrate comprises a bottom silicon layer, a buried oxide layer and a top silicon layer which are stacked upwards in sequence; the optical waveguide region, the wedge-shaped coupling region, the epitaxial region and the grating filtering region are sequentially etched on the top silicon layer; wherein the epitaxial region comprises a first epitaxial region and a second epitaxial region; the first epitaxial region is close to the wedge-shaped coupling region; the grating filtering region is located between the first epitaxial region and the second epitaxial region; the light absorption region comprises a short wave absorption region positioned in the first epitaxial region and a long wave absorption region positioned in the second epitaxial region; the contact electrode comprises an N-type contact electrode and a P-type contact electrode which are located on t