• Optical control of plasmonic heating effects using reversible photo-alignment of nematic liquid crystals
    Giovanna Palermo, Ugo Cataldi, Luciano De Sio, Thomas Bürgi, Nelson Tabiryan and Cesare Umeton
    Applied Physics Letters, 109 , 2016, p191906
    DOI:10.1063/1.4967377 | unige:94069 | Abstract | Article HTML | Article PDF
We demonstrate and characterize an optical control of the plasmonic heat delivered by a monolayer substrate of gold nanoparticles, obtained by modulating the effective refractive index of the neighboring dielectric medium. The effect, which exploits the dependence of the nematic liquid crystal (NLC) refractive index on the molecular director orientation, is realized by using a polarization dependent, light-induced molecular reorientation of a thin film of photo-alignment layer that the NLC is in contact with. For a suitable alignment, plasmonic pumping intensity values ranging from 0.25 W/cm2 to 6.30 W/cm2 can induce up to 17.4 °C temperature variations in time intervals of the order of seconds. The reversibility of the optically induced NLC molecular director orientation enables an active control of the plasmonic photo-induced heat.

Other publications by these authors :
Bürgi, Thomas Cataldi, Ugo De Sio, Luciano Palermo, Giovanna Tabiryan, Nelson 
Umeton, Cesare 
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