Molded Infrared Lens Chalcogenide Glass Material

Traditional infrared lens are grinded, polished or diamond turned to form its surface, in the other words: through “cold manufacturing”. While infrared lens can also be formed through “thermal manufacturing”, here we have molded infrared lens made of chalcogenide glass material. Lens molding is specially suited for large quantity production because the fabrication cost per lens could be controlled to a very low level. Molded lenses also have good product consistency in mass production, which ensure the good reliability of infrared systems.
Chalcogenide glass is not one but a series of glass like amorphous materials which are transmit in the infrared band. We can only choose chalcogendie glass material in infrared lens molding because of their low melting points compared to other infrared materials.
Chalcogenide glass have good transmission rate(>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 infrared application, especially in color correction with germanium lens in optical system.
Unlike germanium which needs to be mined and has limited supply, chalcogenide glass materials are synthetic. Their prices are more stable and acceptable. Lens made of chalcogenide glass can be good replacements of germanium lens that they would play more and more important role in the new designed infrared systems.

Wavelength Infrared can provide molded chalcogenide glass infrared lens with aspheric and diffractive surfaces. Chalcogenide glass lens are most popular for systems operating in the 3-5 mircron or 8-12 micron infrared band, average transmission over 97.5% with anti-reflective coatings (AR coating). Diamond-like carbon coating (DLC coating) or high durable coating (HD coating) can also be applied on the chalcogenide glass infrared lens to provide extra protection against scratch and impact.