title: Subwavelength metallic cavities with high-Q resonance modes.
abstract: Metallic cavities have been extensively studied to realize small-volume nanocavities and nanolasers. However cavity-resonance quality (Q) factors of nanolasers observed up to now remain low (up to ∼500) due to metal optical absorption. In this paper, we report the observation of highest Q factors of 9000 at low temperature and ∼6000 near room temperature in a metallic cavity with a probe of sub-bandgap emission of Si-doped GaAs. We analyze the temperature dependence of cavity-mode resonance wavelengths and show that the refractive-index term dominates the measured temperature dependence. We also show that this refractive-index term is cavity-mode dependent and the fitting procedure offers a new method to identify cavity modes. We simulate the metallic cavity with finite-element method and attribute the high-Q cavity mode to a whispering gallery optical mode. This mode is shown to have isotropic polarization dependence of the output emission, which is preferable for quantum information applications.
authors: Research Institute for Electronic Science, Hokkaido University, 001-0020 Sapporo, Japan.
authors: Nagisa
authors: N
authors: Ishihara
authors: Hiroyuki
authors: H
authors: Kurosawa
authors: Ryo
authors: R
authors: Takemoto
authors: Nahid A
authors: NA
authors: Jahan
authors: Hideaki
authors: H
authors: Nakajima
authors: Hidekazu
authors: H
authors: Kumano
authors: Ikuo
authors: I
authors: Suemune