Room-temperature polariton waveguide effect in a ZnO microwire

We study the propagation of exciton-polaritons in a one-dimensional ZnO microwire at room temperature. Polaritons are generated by nonresonant optical excitation, and those with nonzero momentum along the c-axis propagate as far as tens of micrometers along the microwire. The momentum distribution of the propagating polariton gas depends on the propagation distance; only the polaritons with large c-axis momenta survive after traveling a long distance owing to the propagation loss of polaritons in such a waveguide system.