Silicon-germanium photoelectric detection apparatus based on on-chip mode converter

Abstract

An on-chip mode converter-based silicon-germanium photoelectric detection apparatus comprises an insulating substrate, an optical coupler, an on-chip mode converter and a multi-mode silicon-germanium photoelectric detector. The optical coupler, the converter and the photoelectric detector are sequentially connected and all fixed on silicon wafers of the insulating substrate. An incident fundamental mode optical signal is transmitted to the optical coupler through a single-mode fiber, enters the converter via the optical coupled. The converter converts the fundamental mode optical signal into a multi-mode optical field and enters the photoelectric detector, which converts the multi-mode optical field into an electrical signal. Heavily germanium-doped region are located in areas with relatively weak distributed light intensity of the multi-mode optical field. The absorption loss of the heavily germanium-doped region and third through-holes on the optical field is dramatically reduced and the responsiveness of the apparatus can be improved effectively.