Directivity of SOI Photodiode with Gold Surface Plasmon Antenna

This paper demonstrates the directivity for incoming light of silicon-on-insulator (SOI) photodiode (PD) with gold (Au) grating type surface plasmon (SP) antenna. Light sensitivity is enhanced when the phase matching condition between the diffracted light from the antenna and propagating wave in the SOI is satisfied, and therefore incident angle detection can be realized. Since the PD is compatible with complementary metal-oxide-semiconductor (CMOS) integrated circuit technology, the results may open up a new field of angle sensitive pixels (ASPs) integrated in a chip for applications such as lensless imaging.