  This article theoretically proposes a multi-layer Fabry-Perot cavity
structure based on nonlinear MoS2, whose cavity is composed of asymmetric
photonic crystals. In this structure, we observed a low threshold optical
bistability phenomenon on the order of a in the visible light band, which is
caused by the large third-order nonlinear conductivity of the bilayer MoS2 and
the Fabry-Perot cavity resonance. Research has found that when light is
incident from two different directions in an asymmetric Fabry-Perot cavity, the
optical bistability exhibits not exactly the same behavior. In addition, we
further investigated and found that the optical bistability behavior in this
simple multi-layer structure is closely related to parameters such as incident
wavelength, Fabry-Perot cavity length, and refractive index of the photonic
crystal dielectric. This work provides a new approach for the implementation of
low threshold optical bistable devices in the visible light band, which is
expected to be applied in nonlinear optical fields such as all optical switches
and all optical logic devices.
