Fusion welding This process requires large amounts of electricity. In most cases transformers are needed to provide enough amps. Resistance welding is a very prevalent form of fusion welding. It is used in the manufacturing of automobiles and construction equipment. Conduction welding, also known as laser beam welding or radiation welding, is a highly precise form of fusion welding. "Laser" is an acronym for Light Amplification by Stimulated Emission of Radiation. The laser emits light in bursts called pumps. These bursts are aimed at the seam of the metals desired to be conjoined. As the laser bursts it is guided along the
Stimulated emission the ground state to transition into the excited state, then what is called a population inversion is created. When light of the appropriate frequency passes through the inverted medium, the photons are either absorbed by the atoms that remain in the ground state or the photons stimulate the excited atoms to emit additional photons of the same frequency, phase, and direction. Since more atoms are in the excited state than in the ground state then an amplification of the input intensity results. The population inversion, in units of atoms per cubic meter, is where "g" and "g" are the degeneracies