Chalcogenide Glass Lens for Infrared Applications

Chalcogenide glass lens is optical lens made of chalcogenide glass. Chalcogenide glass is not one but a series of glass like amorphous materials which are transmit in the infrared band. They featured good transmission(>60%) in the range of 2-12 micron, low index of refraction(2.4-2.8@11micron), low thermal change in refractive index and low dispersion. They have similar mechanical and optical properties to germanium, which make them well suited for IR application, especially in color correction with germanium lens in optical system.

Unlike germanium, which needs to be mined and has limited supply, chalcogenide glass are synthetic and their prices are more stable. Chalcogenide glass have low melt point(200-400℃) compared to other infrared materials, they can be molded into aspheric lens with low cost for large quantity production(”Molded IR-Molded Chalcogenide Glass Lens”). For these two reasons, chalcogenide glass lens would play more and more important role in the infrared applications.

Wavelength Infrared can manufacture a variety shape of chalcogenide glass lens with plane, concave, convex, aspheric and diffractive surfaces. Chalcogenide glass is most popular for systems operating in the 3-5 or 8-12µm spectral region, with anti-reflective coatings (AR coating), the average transmission could be brought up to 97.5-98.5% depend on the bandwidth of the coating. We can also apply diamond-like carbon coating (DLC coating) or high durable coating (HD coating) on lens surface to provide extra protection against scratch and impact.

Wavelength infrared manufactures quality custom spherical and aspheric chalcogenide glass lens. They can either focus or diverge incoming light beam to meet specific requirement of the infrared system. The application could be thermal imaging, thermograph, beam collimating, spectrum analysis and etc.