The use of dielectric and thus absorption-free coatings allows the production of reflexionreducing layer systems

Modern optics is hardly imaginable without anti-reflex coatings, also called AR- or tempering layer. With these layers the reflexion on the surface of an optical medium for a wavelength or a defined spectrum is minimized.

Some of the advantages of anti-reflex coatings on optical components are:

• Increase of transmission of optical systems by minimisation of energy losses
• Suppression of veiling glare and interfering reflexes in image-forming systems
• Avoidance of double images through multiple reflexions, e.g. at windows or prism surfaces
  
  
  

In this example a micro optics (approx. 1 mm x 1 mm x 20 mm) is provided on two surfaces with an anti-reflex coating for the wavelength range of 800...1000 nm. The peculiarity was to achieve a reflexion of R(abs) < 1% for the angles of incidence of AOI = 0...30°.

Absolute measurement of the reflexion with AOI = 0...30°. At 888 nm the change-over point of the spectral photometer to the IR sensor can be seen.

The reflexion measurement with different angles of incidence 0...30° makes only sense if the absolute measurement ("VW" measuring principle) is used. This measurement was carried out on the in-house Lambda 950 with URA.