Based on the second-order nonlinear effect in the periodically thermal/electric-field poling silica optical fiber and starting from the coupled-mode equations, the analytic expressions of nonlinear phase-shift of all-optical switching under the condition of strong pump light are derived in this paper. The nonlinear phase-shift is optimized by selecting the parameters properly.
second-order nonlinear cascading - nonlinear phase-shift - all-optical switching