Measuring the mode volume of plasmonic nanocavities using coupled optical emitters

Abstract

Metallic optical systems can confine light to deep sub-wavelength dimensions, but verifying the level of confinement at these length scales typically requires specialized techniques and equipment for probing the near-field of the structure. We experimentally measured the confinement of a metal-based optical cavity by using the cavity modes themselves as a sensitive probe of the cavity characteristics. By perturbing the cavity modes with conformal dielectric layers of sub-nm thickness using atomic layer deposition, we find the exponential decay length of the modes to be less than 5% of the free-space wavelength (λ) and the mode volume to be of order λ^3/1000. These results provide experimental confirmation of the deep sub-wavelength confinement capabilities of metal-based optical cavities.

11 pages, 4 figures

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• Quantum nature of a strongly-coupled single quantum dot-cavity system
• Quantum Optics with Surface Plasmons
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Cited by in corpus (1)

• Plasmonic Purcell factor and coupling efficiency to surface plasmons. Implications for addressing and controlling optical nanosources