RESUMO
Characterization of individual nanoparticles is a challenge due to the diffraction limit. To overcome this constraint we investigate the transfer of their optical properties to a mechanical degree of freedom of a larger object. From finite-difference time-domain computations, we estimate the mechanical frequency shift caused by metallic nanoparticles traveling through a microfluidic channel. Due to plasmonic effects we find relative shifts on the order of 1% for a 1 mW incident optical power for particles with radius ranging from 25 to 150 nm. The extreme sensitivity of this detection scheme enables real-time and in situ observation of optical dynamics at nanoscale.
RESUMO
Based on the Landauer formalism, we demonstrate that the thermal conductance due to the propagation of Zenneck surface-phonon polaritons along a polar nanowire is independent of the material characteristics and is given by π2kB2T/3h. The giant propagation length of these energy carriers establishes that this quantization holds not only for a temperature much smaller than 1 K, as is the case for electrons and phonons, but also for temperatures comparable to room temperature, which can significantly facilitate its observation and application in the thermal management of nanoscale electronics and photonics.
RESUMO
We have designed photonic crystal suspended membranes with optimized optical and mechanical properties for cavity optomechanics. Such resonators sustain vibration modes in the megahertz range with quality factors of a few thousand. Thanks to a two-dimensional square lattice of holes, their reflectivity at normal incidence at 1064 nm reaches values as high as 95%. These two features, combined with the very low mass of the membrane, open the way to the use of such periodic structures as deformable end mirrors in Fabry-Perot cavities for the investigation of cavity optomechanical effects.
