Abstract: A device implementing polariton optical neural network, comprising: Input layer (100) consisting of optical elements ensuring linear pre-processing and distribution of input optical signals (102), middle layer (104), consisting of nonlinear optical elements, realizing nonlinear transformation of the pre-processed input signals (106), output layer (108) consisting of linear optical elements, realizing linear transformation of the signals that had been transformed nonlinearly (110) and generating output signals, passive optical systems (114) optically coupling the input layer (100), the middle layer (104), the output layer (108) characterized in that the nonlinear transformation in the middle layer occurs as a result of interaction of pre-processed input signals (106) with a nonlinear element or elements in the form of an optical microcavity or multiple optical microcavities hosting exciton-polaritons.