Korth Kristalle GmbH

Refractive Index

1: Si plane parallel window | 2: Camera Lens | 3: Temperature measurement with thermal camera

Infrared Technology

Measuring temperatures and demonstrating temperature distribution is increasingly used in manufacturing and in establishing the energy consumption of buildings. It is essential that the required optical components can be manufactured cost effectively in high volumes.


Windows are optical components that only allow the passage of waves within a specific range.  They come in a range of shapes and specifications (e.g. parallelism, surface quality, dimensional tolerances), depending on the type of application.

Lenses are optical components with two refractive faces, of which at least one is convex or concave. The most important property of a lens or array of lenses is its imaging properties. The most crucial aspect of a lens is its focal length, i.e. the measure of how strongly the system converges (focuses) or diverges (defocuses) light. The simplest lenses are spherical lenses: their two surfaces are parts of the surfaces of spheres, with the lens axis ideally perpendicular to both surfaces. Each of the surfaces can be convex (bulging outwards from the lens) or concave (depressed into the lens). As such, the surfaces can be assigned radii of curvature. A distinction is made between converging lenses (two convex faces or one convex and one planar face; ideally, a beam of light running parallel to the optical axis is collected in one point, the focus) or diverging lenses (two concave faces or one concave and one planar face; a beam of light after passing through the lens appears to be emanating from a particular point on the axis in front of the lens.



• Thermal camera

• FLIR Systems





Zinc Selenide

Zinc Sulphide

Potassium Chloride


Calcium Fluoride

Barium Fluoride


Properties for Thermography