Coherent propagation dynamics of an adiabatic four-waveguide directional coupler: a generic approach

Abstract

A generic model is presented to explore optical analogues of coherent population transfer and trapping in a four-waveguide (WG) directional coupler. In contrast to conventional counterintuitive order for the coupling coefficients, the present model highlights the robustness of the approach irrespective of any particular coupling order with varying conditions of initial light distribution. The coherent propagation characteristics shown by the WG coupler involve all the adiabatic states instead of dark states only.