On-Chip Detection of Multiwavelength Surface Plasmon Polaritons Based on Plasmonic Demultiplexers
Xiaobo He, Huatian Hu, Zhenyu Yang, Yangjian Cai, Wenqiang Wang, Zhanghua Han, Junjun Shi, Hongxing Xu
Abstract
On-chip photodetectors for surface plasmon polaritons (SPPs) have shown great potential in data processing, telecommunication, and integrated photonics. However, to generate, detect, and analyze the SPPs of different wavelengths in the waveguide conventionally involves multiple photonic elements, which will limit the bandwidth and integration degree in integrated circuits. Here, we experimentally demonstrate the separated photodetection of SPPs of multiple wavelengths by utilizing wavelength-dependent beam splitting technology. The proposed SPP photodetector consists of one plasmonic crystal splitter and two planar metal–semiconductor–metal (MSM) photodetection channels. It allows independent electrical detection of SPPs with different wavelengths by the specified MSM photodetector. The response of the individual detector is polarization-dependent on a certain wavelength, which shows that the detection of SPPs is independent after assignment to different detectors. Our results have the potential to provide a highly integrated multichannel detection platform in future plasmonic circuits.