A way of increasing the wavelength selectivity of a low-e coating to approximate that of the ideal solar coating shown in Figure 1 is to micro-structure the conventional low emissivity coating. Instead of the metal layer that is used in the conventional coating, a metal mesh is created on the glass substrate (see Figure 3).

The most important property of this mesh is the distance between the metal bridges. If this distance is small compared to the IR wavelengths, the coating behaves as a homogenous metal layer or a conventional low-e IR coating. For visible radiation, for which the wavelength is small compared to the distance between the metal bridges, transmission is only slightly reduced (see Figure 4).

For wavelengths greater than the the radiation is reflected. For most ofthe radiation is transmitted.