  In this work we briefly review the studies of the optical constants of
monolayer transition metal dichalcogenides and few layer black phosphorus, with
particular emphasis to the complex dielectric function and refractive index.
Specifically, we give an estimate of the complex index of refraction of
phosphorene and few-layer black phosphorus. We extracted the complex index of
refraction of this material from differential reflectance data reported in
literature by employing a constrained Kramers-Kronig analysis. Finally, we
studied the linear optical response of multilayer systems embedding phosphorene
by using the transfer matrix method.
