Photonic computing, storage, and communication are the foundation for future photonic chips and all-optical neural networks. Nanoscale plasmons, with their ultrafast response speed and ultrasmall mode volume, play an important role in the integration of photonic chips. However, due to the limitations of materials and fundamental principles in many previous systems, they are often incompatible with existing optoelectronics, and their stability and operability are greatly compromised.
A recent report in National Science Review (Natl. Sci. Rev. 2024 11(5), nwad280) describes a research on the dynamic and reversible optical modulation of surface plasmons based on the transport of hot carriers. This research combines the high-speed response of metal nanoplasmons with the optoelectronic modulation of semiconductors. By optically exciting the hot electrons, it modulates the charge density in gold and the conductivity of the nanogaps, which ultimately renders reversible and ultrafast switching of the plasmon resonances. Thus, it provides an important prototype for optoelectronic switches in nanophotonic chips. This research was led by the research group of Professor Ding Tao at Wuhan University, in collaboration with Professor Hongxing Xu, Associate Professor Li Zhou and Research Professor Ti Wang, as well as Professor Ququan Wang from the Southern University of Science and Technology.
