Modelling organic polariton transport with saturation

We present a method for calculating spatially resolved dynamics of organic polaritons including both vibronic coupling and incoherent processes. Our method combines mean-field theory with a coarse graining in space to enable simulation of a large molecular ensembles with collective coupling to light. We use this method to investigate the propagation of polaritons in a one-dimensional cavity through regions subject to strong non-resonant pump. We show how pumped regions provide a potential barrier to the polaritons, generally leading to reflection, transmission and amplification or attenuation. We further show how dark and bright excitonic populations may be determined in our model and investigate the role of dark states in the transport in the presence of vibronic coupling. Our results have implications for studies of polariton transport and energy transfer in organic materials and the possibility of pump control and targeted polariton flow for organic polaritonic devices.