Strong coupling between excitons in transition metal dichalcogenides and optical bound states in the continuum

Being 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 Ta 2 O 5 periodic photonic structures and excitons in WSe 2 monolayers. We demonstrate that giant radiative lifetime of BICs allows to engineer the exciton-polariton lifetime enhancing it three orders of magnitude compared to a bare exciton. We show that maximal lifetime of hybrid light-matter state can be achieved at any point of k-space by shaping the geometry of the photonic structure. ; This work was supported by the Russian Foundation for Basic Research (16-37-60064, 17-02- 01234), the Ministry of Education and Science of the Russian Federation (3.1668.2017/4.6), the President of Rus- sian Federation (MK-403.2018.2)