Patterned multilayer metamaterial for fast and efficient photon collection from dipolar emitters

Mechanism of emitters coupled with a polymer-based hyperbolic metamaterial

We study a polymer-based hyperbolic metamaterial (HMM) structure composed of three Au-polymer bilayers with a hyperbolic dispersion relation. Using an effective refractive index retrieval algorithm, we obtain the effective permittivity of the experimentally fabricated polymer-based structure. In particular, the unique polymer-based HMM shows the existence of high-k modes that propagate in the metal-dielectric multilayered structure due to the excitation of bulk plasmon-polaritonic modes. Moreover, we compare the experimental luminescence and fluorescence lifetime results of the multilayered Au and a dye-doped polymer (PMMA) to investigate the dynamics of three different emitters, each incorporated within the unique polymer-based HMM structure. With emitters closer to the epsilon-near-zero region of the HMM, we observed a relatively high shortening of the average lifetime as compared to other emitters either close or far from the epsilon-near-zero region. This served as evidence of coupling between the emitters and the HMM as well as confirmed the increase in the non-radiative recombination rate of the different emitters. We also show that the metallic losses of a passive polymer-based HMM can be greatly compensated by a gain material with an emission wavelength close to the epsilon-near-zero region of the HMM. These results demonstrate the unique potential of an active polymer-based hyperbolic metamaterial in loss compensation, quantum applications, and sub-wavelength imaging techniques.

Harnessing graphene-hBN hyperstructure for single-photon sources

One of the key challenges to move single-photon sources into practical applications is the ability to efficiently extract light from a single quantum emitter while maintaining efficient photon emission. Here, we propose to harness the optical topological transitions of graphene-hBN hyperstructure to engineer the emission from quantum emitters and achieve preferential power extraction. We have designed a hyperstructure, which possesses tunability of spontaneous emission and enhancement of extraction during optical topological transitions from the closed (ellipsoid) isofrequency surface to an open (hyperboloid) isofrequency surface by tuning the chemical potential of graphene. Such an interesting feature relies exclusively on the hyperbolic properties of hBN and tunable behavior of graphene, which is confirmed by detailed calculations and simulations. Remarkably, single-photon sources based on the hyperstructure do not require overmuch microfabrication and they are capable of working at tunable frequency.