Squeezing visible light waves into a 3-nm-thick and 55-nm-long plasmon cavity

National Institute for Materials Science, Tsukuba, Ibaraki, Japan
Physical Review Letters (Impact Factor: 7.73). 04/2006; 96(9):097401. DOI: 10.1103/PhysRevLett.96.097401
Source: PubMed

ABSTRACT We demonstrate controlled squeezing of visible light waves into nanometer-sized optical cavities. The light is perpendicularly confined in a few-nanometer-thick SiO2 film sandwiched between Au claddings in the form of surface plasmon polaritons and exhibits Fabry-Perot resonances in a longitudinal direction. As the thickness of the dielectric core is reduced, the plasmon wavelength becomes shorter; then a smaller cavity is realized. A dispersion relation down to a surface plasmon wavelength of 51 nm for a red light, which is less than 8% of the free-space wavelength, was experimentally observed. Any obvious breakdowns of the macroscopic electromagnetics based on continuous dielectric media were not disclosed for 3-nm-thick cores.

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