Linear and nonlinear optical behavior of epsilon near zero metamaterials: opportunities and challenges

Epsilon-Near-Zero (ENZ) metamaterials (MMs), whose dielectric permittivity approaches zero at specific wavelengths, exhibit exotic physical properties and promising optoelectronic applications. Here we exploit the effective medium approach to obtain the ENZ condition by stacking metal and dielectric materials, with individual subwavelength thickness. Based on this configuration, we investigate optical activity (dichroism and circular birefringence) of 1D chiral MMs enhanced by the ENZ effect and the all-optical transition of ENZ MMs, from metallic to dielectric, as a function of the pumping optical power.