  We investigate the adiabatic evolution of light in nonlinear waveguide
couplers via resonance-locked inverse engineering based on stimulated Raman
adiabatic passage (STIRAP). The longitudinal varying detunings of the
propagation coefficients are designed to eliminate dynamically the nonlinear
effect, which induce the non-adiabatic oscillations. We show that different
light evolutions such as complete light transfer, light split and light return
can be realized adiabatically with appropriate choices of the detunings even in
the nonlinear regime. The features open new opportunities for the realization
of all-optical nonlinear devices with high fidelity in integrated optics.
