Low-capacitance Ultrathin InGaAs Membrane Photodetector on Si Slot Waveguide towards Receiver-less System

We proposed a Si/III-V hybrid waveguide photodetector consisting of an ultrathin InGaAs membrane and Si slot waveguide, enabling low capacitance and high responsivity simultaneously. The strong optical confinement in a Si slot waveguide enhanced optical absorption in the InGaAs membrane. As a result, we successfully demonstrated high responsivity of 1 A/W and sufficiently small capacitance of 1.9 fF to realize a receiver-less (TIA-less) system.