Article

Deep subwavelength plasmonic whispering-gallery-mode cavity

Optics Express (Impact Factor: 3.53). 10/2012; 20(22):24918-24. DOI: 10.1364/OE.20.024918
Source: PubMed

ABSTRACT We propose a plasmonic whispering-gallery-mode cavity comprising of a dielectric disk with sub-hundred nanometer thickness sandwiched by two silver disks. By reducing radius and thickness carefully based on the investigated resonant wavelength dependencies, the surface-plasmon-polariton cavity mode with a resonant wavelength of 1550 nm can be confined in a disk with a radius of 88 nm and a thickness of 10 nm, where the physical size of the cavity is 0.000064 λ0 30: free space wavelength). The cavity mode has a deep subwavelength mode volume of 0.010 (λ/2n)3 and a high quality factor of 1900 at 40K, consequently, a large Purcell factor of 1.1 x 105.

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