Coupling Dynamics and Linear Polarization Phenomena in Codirectional Polariton Waveguide Couplers

In this work, we explore the potential of spin-based integrated devices using polariton waveguides that form codirectional couplers. For suitable coupler parameters, a transfer of condensates between the arms of the coupler, occurs leading to the observation of Josephson-like oscillations. The ability to tune the periodicity of these oscillations opens the way to the design of polaritonic circuits in which the directionality of the signal towards the output terminals can be controlled. We also investigate the response of the devices to linearly polarized excitation, delving into the dynamics of linear polarization at the output terminals of long couplers, providing valuable insights into the potential applications of spin-based polariton devices, including polariton switches and logic gates with efficient operation. Our results are supported by numerical simulations based on generalized Gross-Pitaevskii equation describing the dynamics of coherent polaritons in spatially non-uniform system. We show, how the coupling and the controllable spin degree of freedom in polariton couplers opens avenues for innovative optical architectures and functionalities.