Control of the flow of light in the non-adiabatic regime.

We demonstrate that coupled waveguides systems can be operated in the so called non-adiabatic regime. In this regime, light can undergo transitions between different steady states in a manner analogue to the transition of an electron between energy levels. This approach contrasts with the previous concepts in integrated photonics that rely exclusively on the adiabatic control of the flow of light. We show in particular that abrupt changes of the control parameters are not required to create such non-adiabatic transitions. The constraint for adiabaticity being lifted, light can now be manipulated optimally. And the analogy between the time evolution of a quantum system and the propagation of light in a waveguides array can be pushed one step further. [ABSTRACT FROM AUTHOR]