Vladimir State University , Russia

We study the problem of high-temperature Bose- Einstein condensation of atomic polaritons in a waveguide cavity appearing due to the interaction of two-level atoms with (nonresonant) quantized optical radiation in the strong- coupling regime and in the presence of optical collisions with buffer-gas particles. We propose a special biconical waveguide cavity, permitting localization and trapping of low- branch (LB) polaritons imposed by the variation of the waveguide radius in longitudinal direction. We have shown that the critical temperature of BEC occurring in the system can be high enough