Optical control of plasmonic heating effects using reversible photo-alignment of nematic liquid crystals
Abstract
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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 07, 2016
- Source ID
- 10.1063/1.4967377
Entities
People
- Cesare Umeton
- Giovanna Palermo
- Luciano De Sio
- Nelson Tabiryan
- Thomas Bürgi
- Ugo Cataldi
Organizations
- Air Force Office of Scientific Research
- University of Calabria
- University of Geneva