The optical response of mono-layer transition metal dichalcogenides in a Kerr-type non-linear dielectric environment

The optical behaviour of an embedded mono-layer of transition metal dichalcogenides(TMDC) in a non-linear Kerr-type dielectric environment is studied. The optical response of the TMDC sheet which serves as an interface between a linear and non-linear dielectric medium is qualitatively obtained through transmission and absorption coefficients as a function of the non-linear electromagnetic response of the Kerr-type dielectric and the optical conductivity of the TMDC mono-layer. The optical conductivity is calculated using the Kubo formalism from linear response theory. We show how the optical behaviour in this arrangement can be switched between total internal reflection and a normal transmission regime by controlling the intensity of the incident radiation. Further, the role of the energy spectrum of the mono-layer TMDC is also underscored; we specifically choose MoS$_{2}$ and WSe$_{2}$ which have nearly identical dispersion parameters apart from a much stronger spin-orbit coupling in the latter. The stronger spin-orbit coupling in WSe$_{2}$ manifests as an enhanced reflection spectrum. Finally, we consider the role of external perturbations such as strain and demonstrate that it could effectively be used to modulate the overall optical response. We conclude by offering a brief overview of the applicability of our proposed scheme in various devices that exclusively employ an all-optical switching mechanism through optical bistability which is the hallmark of a non-linear dielectric.