Lesson 9 – Colors in Sources

The optical spectrum ranges from the ultraviolet (UV) to the infrared (IR), but humans can only see the visible (Vis) rainbow. Optical elements called diffraction gratings disperse source light so that colors are separated, with each color made to travel at a different angle. A grating may be used to disperse optical sources to separate and display their constituent colors. In this way, the continuous visible rainbow of an incandescent source may be visualized, the discrete red, green, and blue LED sources within a white-light LED may be separated, and individual spectral lines may be visualized for plasma discharge sources, “neon” signs, and fluorescent lamps.