We use the FWHM of the AFM-IR signal distribution profile, as depicted in Figure to determine the achievable spatial resolution. Experiments and models agree that increasing the laser repetition rates led to a decrease in FWHM, indicating improved spatial resolution. In the following section, we show that this effect can be understood through the PSF model. The model and simulation also agree well when it comes to the effect of pulse width. When keeping the repetition rate around 282 kHz and varying the pulse width from 100 ns to 500 ns at constant peak pulse power, a linear dependence of peak and integrated amplitude on the pulse width is found (see Figs.6). To compare modeled and measured amplitude a scaling factor is required, as the models directly output surface deflection, while the AFM-IR signal is proportional to surface deflection but has several sensitivity constants that are difficult to determine. We use a scaling factor of (13.61 ± 1.14) nm/V, which was determined as described in Methods.