Rainbow effect
(spectral interferences)
In case of insulating glass panes, manufactured out of float glass, interference may appear in the form of a colored spectrum. This effect is known also under the name of „Newtons Rings”. Optical interference represents the apparent superposing of two or more luminous rays which meet in the same point. They appear in the form of more or less colored areas, which are changing relatively to pressure conditions. This effect is accentuated by the parallel flat surfaces of glass panes, especially when the glass sheets have identical thicknesses. Interference may be diminished using a coating procedure (special glass) at least on one side of the double insulating glass unit, or by employing different glass thicknesses.
