Ultrafast Time-domain Optics

ticle provides a foundation for appreciating some of the key issues that arise in the computational aspects of ultrafast time-domain optics. Because temporal dispersion exists in all materials, it is fundamental to describing the optical field in material bodies when the field is pulsed, especially when the pulse is either ultrashort or ultrawideband. Temporal dispersion implies that the material response is a function of the optical frequency; for example, temporal dispersion causes the separation of white light into the colors of the rainbow. Because of its central importance, the proper representation of the material dispersion in numerical calculations of ultrashort pulse dynamics is critical to obtaining accurate results. Employing an extremely accurate numerical technique while simultaneously using an inadequate approximation of the material dispersion is counterproductive, especially when approximating the material dispersion might be unnecessary in the first place. With the proper causal description of temporal dispersion serving as a baseline, we then can include additional material properties as required by the particular problem at hand.