Detailed information for integrating sphere materials

Integrating sphere is important for the measurement but how many people have a clear understanding of its material? How many people know its component in a detailed way? I think it remains to be debated. Now please fix your attention on the following articles, and it is bound to surprise you.

The integrating sphere‘s lining optical properties greatly affect its measurement accuracy. Different coatings must be used at visible, infrared and ultraviolet wavelengths. High-powered light sources may heat or damage the coating, so an integrating sphere will be rated for a maximum level of incident power. Different kinds of coating materials are used. Early experimenters used a deposit of magnesium oxide. Barium sulfate has a useful flat reflectance over the visible spectrum. Finely-deposited gold is used for infrared measurements. Various proprietary PTFE compounds are also used for visible light measurements.

The theory of an integrating sphere assumes a uniform inside surface. Ports for detectors and sources must be small, not more than 5% of the surface area of the integrating sphere, for the theoretical assumptions to be valid. Unused ports in commercially built spheres may have matching plugs made up, with the interior surface of the plug coated with the same material as the rest of the integrating sphere. A baffle may be inserted in the integrating sphere so that the direct path of light from a source to a detector is blocked, since this light will have non-uniform distribution.