Simulation research of high-efficiency unidirectional vertical coupling grating couplers for optical through-silicon vias in 3D optoelectronic integrated circuits.

A unidirectional vertical coupling structure is designed based on optical through-silicon vias (TSVs) and gratings to couple and steer the optical interconnects in 3D optoelectronic integrated circuits. The optical TSVs provide high-speed vertical optical data transmission over short distances. The grating coupler structure achieves efficient coupling between an optical TSV and a planar Si waveguide. Through the action of a mirror that covered the end of the optical TSV cladding and a distributed Bragg reflector(DBR) positioned on the far side away from the waveguide, coupling efficiency of 80% at 1550 nm is obtained in simulations. Our proposed vertical coupling structure represents a high-efficiency solution for 3D optical interconnects and can play an important role in 3D optoelectronic integrated circuits. • A grating coupler for optical TSV is designed to realize the coupling between optical TSV and planar waveguide. • A metal mirror is added to the end of the optical TSV cladding in order to improving coupling efficiency. • A distributed Bragg reflector (DBR) mirror is installed on the left side of the waveguide to ensure the unidirectional output of light. [ABSTRACT FROM AUTHOR]