A basic mirrored counterpropagating quasi-phase-matched device is studied w
ith a pulsed input fundamental plane wave using the method of lines and the
relaxation method. Several examples are given under varying spatial pulse
length to device length ratios. An approximate upper bound on the device le
ngth is established from this study for practical pulsed applications; the
largest usable length is approximately the same as the spatial length of th
e pulse. (C) 1999 Optical Society of America.