Few Cycle Optical Pulse Propagation: a detailed calculation
  This document contains my detailed calculation of the Generalised Few-cycle Envelope Approximation (GFEA) propagation equation reported and used in Phys. Rev. A (submitted) and its associated longer version at arXiv.org. This GFEA propagation equation is intended to be applicable to optical pulses only a few cycles long, a regime where the standard Slowly Varying Envelope Approximation (SVEA) fails. 
P. Kinsler