Fig. 4: Photothermal force maps show the temporal evolution of the nanoscale thermal profile.
From: Visualizing ultrafast photothermal dynamics with decoupled optical force nanoscopy
a The average elevated temperature of the nanorod and the laser intensity as a function of time within one period. Simulated thermal expansion at the time frame of (b) 100 ns (with respect to the beginning of the optical pulse), (c) 300 ns, (d) 1000 ns, (e) 1500 ns, and (f) 2900 ns. g–k Measured photothermal force map dynamics at \({f}_{opt}-{f}_{0}\) of −1.5 kHz, and \({f}_{d}-{f}_{0}\) of 0.95 kHz, 0.75 kHz, 0.65 kHz, 0.25 kHz, and −0.15 kHz respectively. The free air amplitude is 100 mV, which corresponds to 15.9 nm. The measurement uses a setpoint of 70%.
