We present a new approach to all-optical switching in nonlinear Bragg
gratings. In contrast to previous schemes in which the system remains
in the switched state for a short length of time we permanent switch a
CW probe from a state of high reflectivity to a low reflectivity stat
e using a short optical pump. Finally we discuss the practicality of t
he device. (C) 1998 Elsevier Science B.V.