Aberrationless approach for diffraction of pulses at linear interfaces

The diffraction of temporally Gaussian shaped light pulses is theoretically studied by means of the aberrationless approach, a theoretical technique p reviously used for spatially bounded beams of unlimited time extension and which is extended here to time domain. We consider linear interfaces, that is. we assume that the spectral components of the vector field in the diffr acted pulse are linearly related with the spectral components of the vector field in the incident pulse. In our analysis pulse deformations are descri bed in terms of the following effects: time delay, focal displacement. wais t modification and change in propagation velocity. Expressions for these ef fects, the time domain analogues of those already reported in the spatial d omain. are given and compared with those obtained using the stationary phas e method. The theory is used to calculate deformations of a short light pul se at a flat interface near conditions of total internal reflection. (C) 20 01 Published by Elsevier Science B.V.