Fast and bright spontaneous emission of Er(3+) ions in metallic nanocavity.
Nat Commun 2015;
6:7080. [PMID:
25940839 PMCID:
PMC4432579 DOI:
10.1038/ncomms8080]
[Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2014] [Accepted: 03/31/2015] [Indexed: 11/09/2022] Open
Abstract
By confining light in a small cavity, the spontaneous emission rate of an emitter can be controlled via the Purcell effect. However, while Purcell factors as large as ∼10,000 have been predicted, actual reported values were in the range of about 10–30 only, leaving a huge gap between theory and experiment. Here we report on enhanced 1.54-μm emission from Er3+ ions placed in a very small metallic cavity. Using a cavity designed to enhance the overall Purcell effect instead of a particular component, and by systematically investigating its photonic properties, we demonstrate an unambiguous Purcell factor that is as high as 170 at room temperature. We also observe >90 times increase in the far-field radiant flux, indicating that as much as 55% of electromagnetic energy that was initially supplied to Er3+ ions in the cavity escape safely into the free space in just one to two optical cycles.
The Purcell effect predicts a spontaneous emission rate enhancement of several orders of magnitude, but experimental demonstrations have been much lower. Here, Song et al. show emission enhancement of Er3+ ions in a metallic nanocavity with a 170 Purcell factor at room temperature and 55% extraction efficiency.
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