Optical / Decorative coatings

The purpose of optical coating is manipulation of the light-film surface interaction. These include antireflection coatings, high reflection coatings and decorative / colored coatings among others. Transparent polymers and glass are the most often used substrates for optical coatings. Even if they are "transparent", the air / substrate interface reflects light ~4% from both surfaces. This is a problem in ambient light conditions for multicolour displays ... direct sunlight in the worst case is reflected from the display surface "obscuring" the original image completely. Antireflection coatings can reduce the reflection over the whole visible spectrum to below 1%. The problem is to find a low heat load deposition method for a film that sticks well on the substrate, has suitable refractive index and does not easily wear out. The most commonly used optical coatings are MgF₂, SiO₂, TiO₂, Al₂O₃. The ultra short pulsed laser deposition (USPLD) method is commonly regarded as most suitable for low heat load optical coatings. Their deposition rates are directly proportional to average power of the laser, which so far has been limited to few watts. Corelase has developed power scalable X-LASE platform that for the first time can be developed into an industrial tool for optical thin film coatings. One of the initial demo film made by X-LASE is shown in the photo above.