While the results reported above show that significant Tjumps are achievable with a single pump pulse, even larger heating magnitudes are possible by changing the pump trigger to initiate a variable-length burst of pump pulses at 1 kHz, pumping the sample repeatedly in quick succession. This approach has similarities to the modulated CW laser heating method reported for solution studies by Ashwood, et al. but retains nanosecond time resolution and direct excitation of fundamental modes. Figure compares the sample heating in a single-pulse heating experiment on HOD in ZSM-5 at TInit = 125 °C with the same sample pumped with a 25-pulse burst. This experiment was performed with the pump OPO set at a wavelength of 2.9 μm rather than the 2.8 μm used in the results reported above, an area of the sample IR spectrum with lower absorbance, explaining the smaller T-jumps achieved here than for the same starting conditions in Figure .