Polaritonic critical coupling in a hybrid quasibound states in the continuum cavity– <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mi>WS</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math> monolayer system

We theoretically propose and numerically demonstrate that perfect feeding of a polaritonic system with full electromagnetic energy under one-port beam incidence, referred to as critical coupling, can be achieved in hybrid dielectric metasurface--${\mathrm{WS}}_{2}$ monolayer structure. Polaritonic where coupling strong are simultaneously attained, is determined by the relative damping rates cavity resonance, ${\ensuremath{\gamma}}_{Q}$, provided symmetry-protected quasibound states continuum cavity, excitonic resonance ${\mathrm{WS}}_{2}$ monolayer, ${\ensuremath{\gamma}}_{X}$. reveal population polariton tuned asymmetry parameter continuum. Furthermore, designed while ${\ensuremath{\gamma}}_{Q}={\ensuremath{\gamma}}_{X}$, only ${\ensuremath{\gamma}}_{Q}\ensuremath{\ne}{\ensuremath{\gamma}}_{X}$. This work enriches study physics controlled absorbance may guide design application efficient polariton-based light-emitting or lasing devices.