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arXiv · 1907.06573

Amplitude and phase control of guided modes excitation from a single dipole source:engineering far- and near-field directionality

Michela F. Picardi·Anatoly V. Zayats·Francisco J. Rodríguez-Fortuño
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Abstract

The design of far-field radiation diagrams from combined electric and magnetic dipolar sources has recently found applications in nanophotonic metasurfaces that realize tailored reflection and refraction. Such dipolar sources also exhibit important near-field evanescent coupling properties with applications in polarimetry and quantum optics. Here we introduce a rigorous theoretical framework for engineering the angular spectra encompassing both far- and near-fields of electric and magnetic sources and develop a unified description of both free space and guided mode directional radiation. The approach uses the full parametric space of six complex-valued components of magnetic and electric dipoles in order to engineer constructive or destructive near-field interference. Such dipolar sources can be realized with dielectric or plasmonic nanoparticles. We show how a single dipolar source can be designed to achieve the selective coupling to multiple waveguide modes and far-field simultaneously with a desired amplitude, phase, and direction.

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Michela F. Picardi, Anatoly V. Zayats, Francisco J. Rodríguez-Fortuño. 2019-07-15. Amplitude and phase control of guided modes excitation from a single dipole source:engineering far- and near-field directionality. https://doi.org/10.1002/lpor.201900250

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