It is the f theta lens for CO2 laser made by a single lens of zinc selenide (ZnSe).
These are used as in the laser marking system.
◦It is a compact and lightweight because it is composed of a single lens.
◦The design and use are processed to an optimum shape of various aberrations becomes smaller.
◦There are wide variety of the lineup that scan area is 50mm to 300mm.
Important： Treatment of ZnSe optics
ZnSe（Zinc selenide） is Poisonous and Deleterious Substances classified as legal, Depending on the specifications, the certificate of delivery may be required acquisition of Poisonous and Deleterious Substances.In addition, ZnSe Optics disposal after use is prohibited in general.
By using the f theta lens, it is possible to be moved a laser light spot in constant speed linear motion on the focal plane by scanning the mirrors such as galvanometer scanner mirrors. The f theta lens enables this by the effect of distortion. Mathematically it is expressed as following; focal length = “f”, ideal image height = “x”, the angle of scanned = “θ” therefore, x = fθ. In the normal single lens, the ideal image height “x” is represented by “x = f tanθ”. Characteristics of both are the same in a small angle range. However, the difference is greater angle increases.