Spatial chirp in ultrafast optics

Spatial chirp is a common spatio-temporal effect, but its parameterization is currently unsatisfactorily vague. In this paper, we propose and compare two definitions of spatial chirp, which we call "spatial dispersion" and "frequency gradient". The appropriate definition to use depends on the application. For Gaussian beams and pulses, the relationship between the two definitions is found to be analogous to that between the definitions of temporal chirp in the time and frequency domains. (C) 2004 Elsevier B.V. All rights reserved.