Hyperbolic metamaterials coupled with single nanoantenna for efficient energy coupling and functionalized photon emission

Hyperbolic metamaterials (HMMs) with highly anisotropic dispersion have shown their unique advantages in constructing platforms for enhancing and manipulating light–matter interactions. However, it is challenging to substantially utilize the enhancing effect of HMMs because of the large momentum mismatch between photons in HMMs and in free space. In addition, the functionalization of HMMs has not yet been sufficiently explored, leaving great unachieved developments of relative nanophotonic systems. Here, we realize effective energy coupling by simply applying a single plasmonic nanoantenna onto the surface of HMMs. In terms of the external light source, the incident light can be coupled into the HMMs and focused at nanoscale regions by the nanoantenna, indicating the potential for precise spatial control of light–matter interactions. As for photon emitters inside the HMMs, the out-coupled light energy is conspicuously enhanced, and, with rational position arrangement, emitters with different wavelengths can be enhanced and out-coupled by the same structure. Furthermore, by engineering the morphology of the nanoantenna, a multiwavelength photon routing device is designed, where the photons with different wavelengths can be split by both propagating directions and polarization. This scheme of single nanoantenna hybridized HMMs will not only benefit further applications of HMMs but also provide new inspiration for the design of plasmonic-based light manipulation devices.