  In the $\gamma$-ray Cherenkov Astronomy framework mirror coating plays a
crucial role in defining the light response of the telescope. We carried out a
study for new mirror coating solutions with both a numerical simulation
software and a vacuum chamber for small sample production. In this article, we
present a new mirror coating solution consisting of a 28-layer interferometric
SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose
average reflectance is above $90\%$ for normally incident light in the
wavelength range between 300 and 550 nm.
