Open AccessA plasmon ruler based on nanoscale photothermal effect
Author(s) -
Weichun Zhang,
Qiang Li,
Min Qiu
Publication year - 2013
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.21.000172
Subject(s) - scaling , plasmon , materials science , particle (ecology) , optics , nanoscopic scale , surface plasmon resonance , discrete dipole approximation , ruler , coupling (piping) , nanoparticle , nanotechnology , physics , quantum mechanics , geometry , oceanography , scattering , geology , mathematics , metallurgy
The determination of nanoscale distances or distance changes necessitates a nanoscale ruler. In the present paper, distance dependence of particle temperature in an optically heated gold nanoparticle pair is quantitatively investigated to explore the possibility of creating a plasmon ruler based on this effect. The two origins of the distance-dependence, i.e., electromagnetic coupling and thermal accumulative effect, are studied. For the particle temperature, a scaling behavior is found, and it suggests that the decay of particle temperature with the interparticle gap for different particle sizes follows a common exponential decay equation. This scaling behavior is qualitatively explained with a simple dipolar-coupling model combined with a point heat source interaction model. On the basis of this scaling behavior of absorption power, we further establish a plasmon ruler equation relating the particle temperature and the interparticle distance. Our findings can serve as an excellent guideline for designing and optimizing temperature-based plasmon rulers.