Hybrid epsilon-near-zero modes of photonic gap antennas

Article

关键词: LARGE OPTICAL NONLINEARITY;    INDIUM TIN OXIDE;    WAVE-GUIDES;    2ND-HARMONIC GENERATION;    SILICON;   

DOI  :  10.1103/PhysRevB.105.165126

来源: SCIE

【 摘 要 】

We demonstrate that in photonic gap antennas composed of an epsilon-near-zero (ENZ) layer embedded within a high-index dielectric, hybrid modes emerge from the strong coupling between the ENZ thin film and the photonic modes of the dielectric antenna. These hybrid modes show giant electric field enhancements, large enhancements of the far-field spontaneous emission rate, and a unidirectional radiation response. We analyze both parent and hybrid modes using quasinormal mode theory and find that the hybridization can be well understood using a coupled oscillator model. Under plane-wave illumination, hybrid ENZ antennas can concentrate light and achieve local electric field amplitudes more than two orders of magnitude greater than that of the incident wave. This places them on par with the best plasmonic antennas. In addition, the far-field spontaneous emission rate of a dipole embedded at the antenna hotspot can be increased by more than three orders of magnitude as compared to that in free space, with nearly perfect unidirectional emission.

【 授权许可】

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