We report on intensity-dependent snitching in Lithium niobate directio
nal couplers. Large nonlinear phase shifts that are due to cascading d
etune the coupling between the coupler branches, which makes all-optic
al snitching possible. Depending on the input intensity, the output co
uld be switched between the cross and the bar coupler branches with a
switching ratio of 1:5 and a throughput of 80%. (C) 1996 Optical Socie
ty of America.