Optical bistability with bound states in the continuum in dielectric gratings

We consider light scattering by dielectric gratings supporting optical bound\nstates in the continuum. Due to the presence of instantaneous Kerr nonlinearity\nthe critical field enhancement in the spectral vicinity of the bound state\ntriggers the effect of optical bistability. The onset of bistability is\nexplained theoretically in the framework of the temporal coupled mode theory.\nAs the central result we cast the problem into the form of a singly\nfield-driven nonlinear oscillator. The theoretical results are verified in\ncomparison against full-wave numerical simulations.\n