2 research outputs found

    THz Generation from Plasmonic Nanoparticle Arrays

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    We investigate the generation of THz pulses when arrays of silver nanoparticles are irradiated by femtosecond laser pulses, providing the first reproducible experimental evidence in support of recent theoretical predictions of such an effect. We assess our results in the context of a model where photoelectrons are produced by plasmon-mediated multiphoton excitation, and THz radiation is generated via the acceleration of the ejected electrons by ponderomotive forces arising from the inhomogeneous plasmon field. By exploring the dependence of the THz emission on the femtosecond pulse intensity and as a function of metal nanoparticle morphology, and by comparing measurements to numerical modeling, we are able to verify the role of the particle plasmon mode in this process

    Chiral Electromagnetic Fields Generated by Arrays of Nanoslits

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    Using a modal matching theory, we demonstrate the generation of short-range, chiral electromagnetic fields via the excitation of arrays of staggered nanoslits that are chiral in two dimensions. The electromagnetic near fields, which exhibit a chiral density greater than that of circularly polarized light, can enhance the chiroptical interactions in the vicinity of the nanoslits. We discuss the features of nanostructure symmetry required to obtain the chiral fields and explicitly show how these structures can give rise to detection and characterization of materials with chiral symmetry