Abstract-Optical Fano resonance of an individual semiconductor nanostructure

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        a, Schematic illustrating how a semiconductor nanostripe enables measurement of the far-field

           scattering and near-field energy storage using a photocurrent measurement.

  b,. SEM image of a fabricated Si nanostripe photodetector.

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Pengyu Fan, Zongfu Yu, Shanhui Fan, Mark L. Brongersma

http://www.nature.com/nmat/journal/vaop/ncurrent/full/nmat3927.html

Fano resonances with a characteristic asymmetric line shape can be observed in light scattering, transmission and reflection spectra of resonant optical systems¹. They result from interference between direct and indirect, resonance-assisted pathways. In the nanophotonics field, Fano effects have been observed in a wide variety of systems, including metallic nanoparticle assemblies², metamaterials^2, 3 and photonic crystals^4, 5. Their unique properties find extensive use in applications, including optical filtering, polarization selectors, sensing, lasers, modulators and nonlinear optics^{6, 7, 8, 9, 10, 11}. We report on the observation of a Fano resonance in a single semiconductor nanostructure, opening up opportunities for their use in active photonic devices. We also show that Fano-resonant semiconductor nanostructures afford the intriguing opportunity to simultaneously measure the far-field scattering response and the near-field energy storage by extracting photogenerated charge. Together they can provide a complete experimental characterization of this type of resonance.