  We report on novel exciton-polariton routing devices created to study and
purposely guide light-matter particles in their condensate phase. In a
co-directional coupling device, two waveguides are connected by a partially
etched section which facilitates tunable coupling of the adjacent channels.
This evanescent coupling of the two macroscopic wavefunctions in each waveguide
reveals itself in real space oscillations of the condensate. This
Josephson-like oscillation has only been observed in coupled polariton traps so
far. Here, we report on a similar coupling behavior in a controllable,
propagative waveguide-based design. By controlling the gap width, channel
length or the propagation energy, the exit port of the polariton flow can be
chosen. This co-directional polariton device is a passive and scalable coupler
element that can serve in compact, next generation logic architectures.
