Open AccessTunable enhanced spontaneous emission in plasmonic waveguide cladded with liquid crystal and low-index metamaterial
Author(s) -
Hao He,
Juanjuan Ren,
Hongyi Chen,
Iam Choon Khoo,
Ying Gu,
Qihuang Gong
Publication year - 2017
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.25.003433
Subject(s) - materials science , plasmon , optics , cladding (metalworking) , refractive index , metamaterial , optoelectronics , surface plasmon , modulation (music) , laser , spontaneous emission , physics , acoustics , metallurgy
The control and enhancement of the spontaneous emission (SE) of emitters embedded in subwavelength structures are fundamentally interesting and of practical interest. For example, in plasmonic lasers and on-chip single photon sources, a large SE rate and the active modulation of SE over a very broad spectral band are highly desired functionalities. In this paper, we demonstrate by an explicit theoretical calculation that a plasmonic waveguide cladded with liquid crystals (LCs) and low-index metamaterials can give rise to an enhancement in the intrinsic SE rate γ 0 of more than two orders of magnitude. Furthermore, by varying the refractive index of the LC cladding, thereby changing the density of states of the surface plasmons, the enhanced SE rate can be modulated over a very large range, e.g., from 131γ 0 to 327γ 0 . In general, the modulation range increases with the anisotropy in the refractive index of the LC, while for a fixed range of modulation, the SE rate is larger with lower cladding indices. These results for active modulation and enhanced SE may find application in enabling low-threshold plasmonic nanolasers and tunable on-chip single photon sources.