  We present a new approach to long range coupling based on a combination of
adiabatic passage and lateral leakage in thin shallow ridge waveguides on a
silicon photonic platform. The approach enables transport of light between two
isolated waveguides through a mode of the silicon slab that acts as an optical
bus. Due to the nature of the adiabatic protocol, the bus mode has minimal
population and the transport is highly robust. We prove the concept and examine
the robustness of this approach using rigorous modelling. We further
demonstrate the utility of the approach by coupling power between two
waveguides whilst bypassing an intermediate waveguide. This concept could form
the basis of a new interconnect technology for silicon integrated photonic
chips.
