Hyperbolic metamaterial resonator–antenna scheme for large, broadband emission enhancement and single-photon collection

Abstract

We model the broadband enhancement of single-photon emission from color centres in silicon carbide nanocrystals coupled to a planar hyperbolic metamaterial (HMM) resonator.The design is based on positioning the single photon emitters within the HMM resonator, made of a dielectric index-matched with silicon-carbide material. The broadband response results from the successive resonance peaks of the lossy Fabry-Perot structure modes arising within the high-index HMM cavity. To capture this broadband enhancement in the single photon emitter's spontaneous emission, we placed a simple gold based cylindrical antenna on top of the HMM resonator. We analyzed the performance of this HMM coupled antenna structure in terms of the Purcell enhancement, quantum efficiency, collection efficiency and overall collected photon rate. For perpendicular dipole orientation relative to the interface, the HMM coupled antenna resonator leads to a significantly large spontaneous emission enhancement with Purcell factor of the order of 250 along with a very high average total collected photon rate (CPR) of about 30 over a broad emission spectrum (700 nm -1000 nm). The peak CPR increases to about 80 at 900 nm, corresponding to the emission of silicon-carbide quantum emitters. This is a state-of-the art improvement considering the previous computational designs have reported a maximum average CPR of 25 across the nitrogen-vacancy centre emission spectrum, 600 nm to 800 nm with the highest value being about 40 at 650 nm.

Hyperbolic Metamaterial with Quantum Dots for Enhanced Emission and Collection Efficiencies

“…This match is presented in a previously published study by one of the authors. [23] Also, the accuracy/correctness of the computational results is further validated by the good match between the theoretical and computational results presented here for the case of 5-layered HMM structure (Figure 1c).…”

“…[8] Recently, hyperbolic metamaterials (HMM) structures, made of sub-wavelength thick alternate planar metal and dielectric layers, have been proposed to provide broadband enhancement to the spontaneous emission of various solid-state emitters based on QDs as well as nanodiamonds. [19][20][21][22][23][24][25][26] These HMM structures have a highly anisotropic permittivity tensor with metallic properties along some and dielectric properties in the other directions. This anisotropy provides the HMM a hyperbolic dispersion with the high-k modes having unbounded momentum values along specific directions in the ideal and lossless case.…”

“…[21] Recently, the performance of a 5-layered planar HMM structure comprising of gold (Au) and zinc sulfide (ZnS) layers was computationally studied for the SiC based emitters with emission peak around 900 nm. [23] To overcome many of these issues, in this report we present the design, fabrication and optical characterization of a 5-layered HMM structure comprising of alternate metal, silver (Ag) and dielectric, titanium dioxide (TiO 2 ) layers with CdSeS/ZnS core/shell alloyed QDs embedded in the middle layer. The near index-matching of the refractive index of TiO 2 (≈2.4 at 660 nm as measured by spectroscopic ellipsometer) with that of the ZnS (≈2.35) shell of the QD allows for the effective out-coupling of the QD emission.…”

Hexagonal boron nitride: a review of the emerging material platform for single-photon sources and the spin–photon interface

“…These high-k modes have unbounded momentum values along specific directions [161]. These structures provide an emitter with a large LDOS together with high emission directionality [162,163]. Recently, Imran et al [164] has proposed a computational design for a graphene-h-BN planar HMM structure for effective extraction of SPE from h-BN-based quantum emitters.…”

Efficient radiational outcoupling of electromagnetic energy from hyperbolic metamaterial resonators

“…Metamaterial approach allows introducing additional design flexibility as compared with conventional approaches. For example, high-gain antenna design 23 , scattering suppression devices 24 , 25 , resonators for radiation efficiency enhancement 26 , hyperbolic metamaterial-based antennae 27 , 28 , and several others configurations have been proposed.…”