what are the spesificities of helium cadmium laser?
Helium-cadmium (HeCd) laser isessentially a metal-vapor laser, its emission has wave lengthes of 441.563 nm and 325 nm. The pumping ability originates from the electrical discharge in metal vapor mixed with helium buffer gas. He-Cd lasers are used in printing and typesetting applications, fluorescence excitation examination (i.e. in U.S. paper currency printing), scientific research, etc.