Results of irradiation of the OH-stretch of pure pASW with different macropulse energies. (a) Infrared spectra of three almost identical pASW depositions prior to on-resonance irradiation. To image the result of the on-resonance irradiation with the OH-stretch pre-irradiation spectra like in (a) were subtracted from post-irradiation spectra, resulting in the difference spectra in (b). The irradiations are performed with increasing macropulse energy (lighter colours). In (c), the absolute area of the changes in the region between the two dashed red lines in (b) as a function of the macropulse energy is shown. Circles denote the area of the original difference spectra in lighter colours in the background in (b) and squares indicate the area of the averaged spectra in (b). The dash-dotted line in (c) illustrates a linear extrapolation based on the macropulse-energy-absolute-area relation of the first point at 25 mJ.