Optical Surface Inspection
Anti Reflectance Properties of Coatings
Comparison coated vs. uncoated lens surfaces. Green: Lens with antireflective coating 01. Blue: Lens with antireflective coating 02. Black: Uncoated lens. Red: Reflectance standard BK7 as reference.
On transparent surfaces a certain share of light is reflected and creates stray light. Antireflective coatings are required to reduce this, especially when complex optical systems are designed such as objectives. Therefore it is necessary to validate the calculations of the antireflective coating. From the metrological point of view this means, that the spectrometer must be able to detect a reflectance of 0.1 % with an accuracy of +/- 1 %. Extremely small measurement spots are necessary to use this technology on curved surfaces like lenses.
The instruments of A.S. & Co. match these requirements in many laboratories and production plants of the optical industry for years, because they are equipped with a highly efficient optical pathway in combination with an extremely sensitive cooled spectrometer.
A.S. & Co. aperture modules are special designed to measure on extremely small areas thus enabling investigations even of curved surfaces (here: sealing ring).