On-Chip Electrical Detection of Propagating Surface Plasmon Polaritons in the Top-Down Fabricated Au Nanowire on Silicon-on-Insulator Platform

Plasmonic devices show great potential for integration with microelectronic chips due to their small size and fast speed to create high-performance hybrid optoelectronic circuits. In the miniaturization process of plasmon devices, on-chip detection is indispensable. Currently, on-chip detection of plasmons is achieved only on chemically synthesized nanowires or metal films and is prohibited in lithographically defined metal nanowires due to the large propagation loss and low on-chip detection efficiency. Here, we demonstrated an on-chip surface plasmon polariton detector by placing an externally biased silicon stripe in the near-field range of a top-down fabricated gold nanowire. First, based on strip plasmon waveguides, we confirmed the detection of plasmons through polarization response and wavelength dependence characteristics and optimized the coupling structure. Then, in a nanowire waveguide, we achieved a subwavelength plasmon detector. 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.