The simulated laser pulse heating results in an inhomogeneous temperature distribution in both dimensions of the ZSM-5 pellet (Figure ). Radial temperature inhomogeneity is Gaussian, due to the Gaussian profile of the pump laser beam. Temperature inhomogeneity along z is due to a combination of the absorption of the pump beam as it travels through the sample (resulting in an exponential decay in the amount of energy delivered) and the divergence of the tightly focussed pump beam (resulting in lower intensity at the faces of the pellet than at the pump focus). The highest temperatures in the sample are located in the first half of the pellet depth (See ESI, Section 14).