Aside from the popular comparison between Germanium and silicon windows, Zinc Selenide and Zinc Sulfide are two other compounds serving as base for optical windows, which happen to be often debated. So let us take a closer look into their properties before we jump to other major issues associated to optical products.


In fact, this is the natural form that Zinc takes and it has some quite interesting physical properties! When extracted from the mineral called Sphalerite, it looks all black and dirty, full of impurities.


Zinc Selenide is a compound with a solid state and yellowish shade, that is extremely difficult to find in nature, and whose main resources reside inside the Stilleite, a mineral. Some of its main features are the capacity of acting as a semiconductor and the band gap set around 2.70 eV when enjoying a 25-Celsius degree temperature.Its name is often replaced with the short form of ZnSe and whenever combined with chromium, we are talking about ZnSe:Cr, a compound successfully used as gain medium infrared laser and emitting around the threshold of 2.4 m. When used as optical material for controlling infrared fascicles, it has surprising effects as it transmits any wavelength in between 0.45 and 21.5 m. Specialists consider it a good resource for creating diode lasers or light emitting diodes and the light that it generates has a blue shade.


ZnSe is known in particular for its utility in building laser systems based on carbon dioxide, since it has an impressive thermal shock resistance and a low coefficient of absorption.


As opposed to our first topic of discussion for today, Zinc Sulfide, which is also an inorganic material, is much easier to find in nature.