HeNe Laser: before there were diode based laser pointers, laser beams were produced by exciting mixtures of gases with high voltage and placing a mirror at each end. This vintage laser is based on the original laser design from Bell Labs in 1962 and has just such a configuration and uses a mixture of helium and neon. The red 632.8nm coherent beam comes from Light Amplification through Stimulated Emission of Radiation (LASER), and photons of this wavelength are one of the spontaneous emission lin