Active far-field control of the thermal near-field via plasmon hybridization

Single-particle photothermal heterodyne imagin was exploited to demonstrate localization bias in the photothermal intensity due to preferential heating of one of the nanorods within the pair. Theoretical modelling and numerical simulation have been performed to show how the resulting photothermal images encode wavelength-dependent temperature biases between each nanorod within a heterodimer, demonstrating the ability to actively manage the thermal near-field by simply tuning the color of incident light. Furthermore, the prospects and challenges of photothermal measurements for measuring relative temperature profile will be discussed. (author)