Plasmon-induced transparency, analogue of classical electromagnetically induced transparency, has attracted enormous attention because of its potentially important applications in the fields of integrated photonic devices and ultrahigh-speed information processing chips. Nowadays, the international problem in the field of PIT and applications lie in that it is difficult to realize chip-integrated PIT in the plane parallel the surface of metallic microstructures. This has seriously restricted the study of ultrahigh speed and chip-integrated information processing based on PIT.

Gong’s group proposes an ultracompact on-chip PIT by using single surface plasmon composite microcavity. Small lateral dimension of 600 nm is obtained for the composite nanocavity, which is reduced by one-order of magnitude compared with previous reports. A large shift of 490 nm in the central wavelength of the transparency window is obtained through coating an organic poly(methyl methacrylate) layer. An additional plasmon-induced transparency like effect is achieved in the near-infrared range through coating the poly(methyl methacrylate) cover layer. The research is reported as a cover article in the journal of Advanced Optical Materials (Zhen Chai, Xiaoyong Hu*, Yu Zhu, Sibai Sun, Hong Yang and Qihuang Gong,* “Ultracompact Chip-Integrated Electromagnetically Induced Transparency in a Single Plasmonic Composite Nanocavity”, Adv. Optical Mater. 2, 320 (2014)). This work not only paves a way for the realization of integrated photonic devices, but also opens up the possibility for constructing ultrahigh-speed information processing chips based on plasmonic circuits.

The above works are supported by the Creative Research Group Project of the National Natural Science Foundation of China, the National Basic Research Program of China and the State Key Laboratory of Mesoscopic Physics.