Modern table-top laser systems are capable of generating ultrashort optical pulses with sufficiently high intensity to induce nonlinear optical effects in many of the materials (including air!) that are used in the construction of optical components and systems. In this talk we describe how two of the techniques of computational optics can by provide insight into the complex dynamics that occurs at high intensities.

Firstly we describe how a modified 3+1D nonlinear Schrodinger equation coupled to a rate equation for the plasma density in the dielectric material can be used to simulate pulse propagation and plasma formation in fused silica. In particular we analyze the influence of pulse-shape and beam geometry on the formation of the electron plasma and hence modification in the bulk material. Secondly we use the finite difference time domain (FDTD) technique to simulate ultrashort optical pulse propagation through
dielectric filters.