## Abstract

The strongly localized quasi-static eigenstates (also known as surface-plasmon resonances) which are found in a small nanometric cluster of spherical inclusions can form the basis for some interesting potential applications such as SPASER and nanolens. In a SPASER, a strong coherent electric field, oscillating at a frequency ω in the visible or infra-red spectral range, can be excited in a spatial region whose linear dimensions are much smaller than the wavelength appropriate to that frequency. In a nanolens an incident electromagnetic field, oscillating at such a frequency, can be focused to a spot whose size is much less than the relevant wavelength. An important property of such resonances is their finite radiative lifetime, which is infinite in the strict quasi-static limit. One needs to solve the full Maxwell's equations in order to find the radiative decay rate, and consequently the lifetime, of such an eigenstate. We develop a method for calculating such lifetimes for clusters of closely spaced spherical inclusions. We also discuss how symmetry properties of such a cluster can be exploited to ensure that certain eigenstates have especially long radiative lifetimes.

Original language | English |
---|---|

Article number | 59270I |

Pages (from-to) | 1-12 |

Number of pages | 12 |

Journal | Proceedings of SPIE - The International Society for Optical Engineering |

Volume | 5927 |

DOIs | |

State | Published - 2005 |

Event | Plasmonics: Metallic Nanostructures and Their Optical Properties III - San Diego, CA, United States Duration: 31 Jul 2005 → 3 Aug 2005 |

## Keywords

- Nano-plasmonic
- Nanolens
- Radiative lifetime
- SPASER