Window optical microstructures (review)

The results of research on the development and application of optical elements placed in the upper part of the window in order to redirect sunlight to the ceiling and into the interior of the room have been summarized and analyzed. There has been a steady trend of transferring such devices to the micro level. The article has described the structures and optical characteristics of three types of the optical microstructures embedded in double-glazed windows: microprismatic films, panels with prismatic microstructures on two sides, and films with embedded micro-mirrors. It has been noted that the use of curved surfaces instead of flat ones in microstructures improves the optical properties and increases the uniformity of the redirected sunlight flux. The designs and properties of optical microelectromechanical systems: switchable micro-mirrors and micro-blinds that were manufactured using microelectronics technology, have been generalized.