Atomic monolayers of transition metal dichalcogenides represent an emerging material platform for the implementation of ultra compact quantum light emitters via strain engineering. In this framework, we discuss experimental results on creation of strain induced single photon sources using a WSe 2 monolayer on a silver substrate, coated with a very thin dielectric layer. We identify quantum emitters which are formed at various locations in the sample. The emission is highly linearly polarized, stable in linewidth and decay times down to 100 ps are observed. We provide numerical calculations of our monolayer-metal device platform to assess the strength of the radiative decay 1 rate enhancement by the presence of the plasmonic structure. We believe, that our results represent a crucial step towards the ultra-compact integration of high performance single photon sources in nanoplasmonic devices and circuits.Single photon sources are considered as a key building block for quantum networks, quantum communications and optical quantum information processing. 15 To fully harness the properties of such non-classical light sources, core requirements include their long-term stability, 6,7 brightness 811 and scalability in the fabrication process. Recently, quantum light emission from inorganic two dimensional layers of transition metal dichalcogenides (TMDC) 1216 has been demonstrated. While the nanoscopic origin of tight exciton localization is still to be explored, engineering the morphology of carrier substrates and thus the strain eld in the monolayers 17 has enabled position control over such quantum emitters. 1820 One outstanding problem, which we address in this report, is the emission enhancement of such quantum emitters in atomic monolayers. The layered nature of the materials and their intrinsic robustness with regard to open surfaces (due to absence of dangling bonds) naturally puts plasmonic approaches in the focus of interest. A single dipole emitter close to a plasmonic nanoparticle, which act as an optical antenna, 21,22 experience a modied photonic mode density, leading to enhanced radiative decay rates and thus a spontaneous emission enhancement. The enhanced intensity results from an amplied electric eld intensity due to localized surface plasmon resonance of metal nanoparticles. 18,23,24 Plasmonic tuning of the optical properties of molecules, such as dyes close to a metal surface is a topic which is subject to investigations since the 1980s. Pronounced coupling phenomena of dye molecules with surface plasmon resonances in ultra-thin silver lms has been shown via luminescence and absorption studies, 25 as well as resonant transmission. 26 Enhanced uorescence of molecules coupled to Ag-islands has been studied in, 27 whereas uorescence quenching of dye molecules or colloidal CdSe quantum dots in the closest vicinity of metallic surfaces has also been identied to act signicantly on the emitters' decay dynamics. 28,29 Hence it is important to separate the emitters from the metallic layers via a non-conduct...

Abstract:We propose a plasmonic cavity using the cutoff frequency of a metal-insulator-metal (MIM) first-order waveguide mode, which has a deep subwavelength physical size of 240 × 210 × 10 (nm 3 ) = 0.00013 λ 0 3 . The cutoff frequency is a unique property of the first-order waveguide mode and provides an effective mode gap mirror. The cutoff frequency has strong dependence on a variety of parameters including the waveguide width, insulator thickness, and insulator index. We suggest new plasmon cavities using three types of cutoff frequency modulations. The light can be confined in the cavity photonically, which is based on the spatial change of the cutoff frequency. Furthermore, we analyze cavity loss by investigating the metallic absorption, radiation, and waveguide coupling loss; the radiation loss of the higher-order cavity mode can be suppressed by multipole cancellation.

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The development of an efficient silicon-based nanolight source is an important step for silicon-based photonic integrated circuits. We propose a high quality factor photonic crystal nanocavity consisting of silicon and silica, which can be used as a silicon-compatible nanolight source. We show that this cavity can effectively confine lights in a low-index silica layer with a high confinement factor of 0.25, in which rare-earth dopants can be embedded as gain materials. The cavity is optimized to have a high quality factor of 15,000 and a mode volume of 0.01 μm3, while the resonance has a wavelength of 1537 nm. We expect that the high confinement factor in the thin silica layer and the high quality factor of the proposed cavity enable the cavity to be a good candidate for silicon-compatible nanolight sources for use in nanolasers or light-emitting diodes in the telecommunication wavelength region.