Spontaneous emission dynamics of Eu³⁺ ions coupled to hyperbolic metamaterials

Sub-wavelength nanostructured systems with tunable electromagnetic properties, such as hyperbolic metamaterials (HMMs), provide a useful platform to tailor spontaneous emission processes. Here, we investigate system comprising Eu3+(NO3)3·6H2O nanocrystals on an HMM structure featuring hexagonal array of Ag nanowires in porous Al2O3 matrix. The HMM-coupled Eu3+ ions exhibit up 2.4 fold increase their decay rate, accompanied by enhancement the rate 5D0 ? 7F2 transition. Using finite-difference time-domain modeling, corroborate these observations photonic density states seen proximity HMM. Our results indicate that HMMs can serve valuable tool control from weak transitions and, hence, hint at route toward more practical applications rare-earth nanoscale optoelectronics and quantum devices.