Professor Qihuang Gong and his team made new progress in the field of hybridized plasmon polariton waveguides. The research was published in the journal of Laser & Photonics Reviews and featured as the back cover of the issue. (Yusheng Bian and Qihuang Gong*, "Deep-subwavelength light confinement and transport in hybrid dielectric-loaded metal wedges," Laser & Photonics Reviews 8(4), 549-561 (2014)).

Hybridized plasmonic waveguides exploiting the coupling between dielectric and plasmonic modes have attracted significant research interests recently due to their remarkable potential to provide improved balance between confinement and loss than their conventional plasmon waveguiding counterparts. However, limited by the mode confinement capability of the SPP modes at planar metal-dielectric interfaces, further downscaling of the hybrid mode area into deep-subwavelength scale is rather challenging. This work proposes to overcome this limitation by using hybrid wedge structures, which consist of triangular metal wedges loaded with nanometric low/high-index dielectric claddings. Owing to the superior guiding properties of wedge plasmons in conjunction with high refractive index contrast near wedge tips, the modal sizes can be squeezed into significantly smaller spaces than those of their conventional wedge and planar hybrid counterparts, while simultaneously featuring propagation distances over tens of micrometers at telecommunication wavelengths. In addition, significantly improved figure of merit, enhanced field confinement inside the low-index gap region, along with reduced waveguide crosstalk can be enabled as well. The presented hybrid dielectric-loaded wedge plasmonic waveguides can be exploited as important building blocks for nanolasers, high-performance passive integrated nanophotonic components as well as high density optically integrated circuits.

This work was supported by the National Key Basic Research Program of China, the Innovative Research Group of the National Natural Science Foundation of China, State Key Laboratory of Mesoscopic Physics, National Natural Science Foundation of China for Young Scholars and the Postdoctoral Science Foundation of China.