As more complicated microscope systems are engineered, the amount of effects taken into account rises steadily. In this context we experienced the need for a simulation approach, that will deliver the intensity distribution in space and time for scanning laser microscopes. To achieve this goal, the frequency space representation of microscope objectives was used and adapted to determine their solution of the electromagnetic wave equation. We describe the steps necessary to efficiently implement an approach to simulate multidimensional solutions of the wave equation. This includes the connection between the back focal plane and the Fourier space representation as well as a proper interpolation method for the latter. The error-potential of our least erroneous interpolation, the power of hann (POH) interpolation, is compared to other common interpolation methods. Finally we demonstrate the current potential of the approach by simulating an “expanding” optical vortex focus.