Light tube

Light tubes (also known as light pipes or tubular skylights) are physical structures used for transmitting or distributing natural or artificial light for the purpose of illumination, and are examples of optical waveguides. Light tubes (also known as light pipes or tubular skylights) are physical structures used for transmitting or distributing natural or artificial light for the purpose of illumination, and are examples of optical waveguides. In their application to daylighting, they are also often called tubular daylighting devices, sun pipes, sun scopes, or daylight pipes. Light pipes may be divided into two broad categories: hollow structures that contain the light with reflective surfaces, and transparent solids that contain the light by total internal reflection. The principles governing the flow of light through these devices are those of nonimaging optics. Manufacturing custom designed Infrared light pipes, hollow waveguides and homogenizers is non-trivial. This is because these are tubes lined with a highly polished infrared reflective coating of Laser Gold, which can be applied thick enough to permit these tubes to be used in highly corrosive atmospheres. Laser Black can be applied to certain parts of light pipes to absorb IR light (see photonics). This is done to limit IR light to only certain areas of the pipe.