Figure 4. Temperature measurement in nanoantennas.

Box plot for the average temperature T, measured for (a) silicon and (b) gold nanoantennas, shown in Fig. 3, excited at resonance. It can be seen that the Au nanoantennas significantly increase their temperature when I_h increases while the Si temperature remains nearly constant. The inset in each figure shows the calculated temperature map around the disks for I_h=5 mW μm⁻² in both cases. Scale bar, 100 nm. (c) Extracted temperature in the gap for selected silicon (cyan) and gold (magenta) nanoantennas as a function of the heating laser intensity at 860 nm. The dashed lines show the numerical calculations for the temperature at the gap, presenting good agreement with the experimental data. The error bars show the s.d. of the temperature measurements, obtained from error propagation from the fluorescence measurements.