Grating enhanced all-optical switching in a Mach-Zehnder interferometer

We consider a Mach-Zehnder interferometer with a nonlinear Bragg grating in one arm, and numerically simulate the time dependent behaviour of the all- optical switch. Compared with the same device without a grating the switchi ng threshold is reduced by a factor of 4, while low pulse distortion is mai ntained for a pulse width of 8.8 ps. Bloch function theory leads to a simpl e model that allows one to estimate the enhancement factor for an arbritrar y grating structure. (C) 1999 Published by Elsevier Science B.V. All rights reserved.