Electrical on-chip detection of propagating surface plasmon with near-field coupling

Abstract

Abstract Plasmonic devices show great potential for integration with the microelectronic chips due to small size and fast speed, in order to create high-performance hybrid optoelectronic circuits. However, the on-chip plasmon detector remains to be explored, for the conventional far field photodetectors are not compatible with plasmon devices because of the complex collecting light path and vertical structure. Here we propose an electrical on-chip plasmon detector by placing an externally biased silicon stripe in the near-field range of plasmon waveguide. Through improving the near-field coupling efficiency and optimizing the plasmon waveguide on SOI, we succeed to achieve a subwavelength plasmon detector where an responsivity of photocurrent is "0.14 mA/W". These results demonstrate the potential of our device as an interface between plasmonic circuits and electronic chips, particularly in applications where the plasmon signals need to be converted into electrical signals for detection or communication.