Koshelev, KirillSychev, S. K.Sadrieva, Zarina F.Bogdanov, Andrey A.Iorsh, I. V.2019-06-242019-06-24K. L. Koshelev, S. K. Sychev, Z. F. Sadrieva, A. A. Bogdanov, and I. V. Iorsh Phys. Rev. B 98, 161113(R)2469-9950http://hdl.handle.net/1885/164165Being motivated by recent achievements in the rapidly developing fields of optical bound states in the continuum (BICs) and excitons in monolayers of transition metal dichalcogenides, we analyze strong coupling between BICs in Ta2O5 periodic photonic structures and excitons in WSe2 monolayers. We demonstrate that the giant radiative lifetime of a BIC allows us to engineer the exciton-polariton lifetime, enhancing it by two orders of magnitude compared to a bare exciton. We show that the maximal lifetime of a hybrid light-matter state can be achieved at any point of k space by shaping the geometry of the photonic structure. Our findings open a different route for the realization of moving exciton-polariton condensates with a nonresonant pump and without Bragg mirrors, which is of paramount importance for polaritonic devices.Theoretical studies have been supported by the megagrant (No. 14.Y26.31.0015) and GosZadanie (No.3.1365.2017/4.6). Simulations of the scattering spectrum have been supported by the Russian Science Foundation (No. 17-12-01581). K.L.K. acknowledges the Foundation for the Advancement of Theoretical Physics and Mathematics “BASIS” for the valuable financial support.application/pdfen-AU© 2018 American Physical Society2018-10-1710.1103/PhysRevB.98.1611132019-03-24