Ultrasmall metal-insulator-metal nanoresonators: impact of slow-wave effects on the quality factor

作者：Yang J^*; Sauvan C; Jouanin A; Collin S; Pelouard J L; Lalanne P

来源：Optics Express, 2012, 20(15): 16880-16891.

DOI：10.1364/OE.20.016880

We study the quality factor variation of three-dimensional Metal-Insulator-Metal nanoresonators when their volume is shrunk from the diffraction limit (lambda/2n)(3) down to a deep subwavelength scale (lambda/50)(3). In addition to rigorous fully-vectorial calculations, we provide a semi-analytical expression of the quality factor Q obtained with a Fabry-Perot model. The latter quantitatively predicts the absorption and radiation losses of the nanoresonator and provides an in-depth understanding of the mode lifetime that cannot be obtained with brute-force computations. In particular, it highlights the impact of slow-wave effects on the Q-factor as the size of the resonator is decreased. The Fabry-Perot model also evidences that, unexpectedly, wave retardation effects are present in metallic nanoparticles, even for deep subwavelength dimensions in the quasi-static regime.

• 出版日期2012-7-16