Controlling spontaneous emission of quantum dot by plasmonic stereo-metamaterials
Tien Lin Shen1*, Tsung Sheng Kao1, Hao-Chung Kuo1
1Department of Photonics & Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, Taiwan
* presenting author:沈天琳,
Plasmonic metamaterials exhibit strong optical field confinements from the enhanced interactions between the constitute mete-molecules and the surrounding materials, while different plasmonic nanostructures can be engineered to support the couplings at different frequencies, thus providing the opportunity to compensate the losses with gain in plasmonic nanosystems especially together with semiconductor quantum dots (QDs) or organic-inorganic dyes towards promising applications such as the compact nanolasers, lasing spaser devices and miniature light-emitting diodes. Among the tremendous research efforts conducted recently, various metamaterial structures hybridized with active materials have been proposed, leading to control the spontaneous emission and induce the enhancement of photoluminescence (PL).
In this paper, we investigate the PL enhancement from semiconductor quantum dots accompanied with stacking metallic asymmetric split-rings (ASR) nanostructures sandwiched with dielectirc SiO2 spacers. By controlling spacing distance with different thicknesses of the dielectric layer, the interactions between the ASR meta-molecules in the logitudinal direction may be modified, giving the enhanced optical porperties at different resonant frequencies. Through calculations, it has been shown that the ASR structure will tremendously enhance the luminescence of quantum dot locating in its vicinity, and the fluorescence of quantum dots can be enhanced by a factor over 4.5. The same enhancement mechanism will be realized on actual device fabricated by e-beam patterning, and then further be applied to other 3D optoelectronic components.

Keywords: quantum dot, dielectric spacer, metamaterial, FDTD, laser