Temperature Measurement in Plasmonic Nanoapertures Used for Optical Trapping
Optical absorption in plasmonic structures lead to a local temperature increase. It was long assumed that in the case of nanoapertures, the extended metal layer was acting as an efficient heat sink to mitigate the warming. However, the reality is that temperature increases higher than 10°C can be readily achieved in gold apertures illuminated by a tightly focused infrared beam of mW power. We find this in a recent article published in ACS Photonics, as we develop three independent fluorescence readouts to measure locally the temperature in single and double nanoholes.
- We provide a clear quantification of the temperature increase in nanoaperture-based optical tweezers
- We establish several methods to locally measure the temperature by recording fluorescence properties (intensity, diffusion time and lifetime). These approaches can be easily implemented and applied to other nanophotonic systems.
- The easy control of the temperature inside nanoapertures opens their use for thermoplasmonics in confined sub-femtoliter volumes for nucleation, polymerization or crystal growth applications.
Also freely available on ArXiv 1906.01947.