The use of a CO<sub>2</sub> laser as a heat source became commercially available for optical fiber splicing and component fabrication only in recent years. In addition to long-term trouble-free and low-maintenance heat source operation, laser fusion splicing offers unique benefits for fabricating high-power optical components, as well as for splice reliability. When used as the heating method for fiber splicing, the energy of the CO<sub>2</sub> laser beam is efficiently absorbed by the outer layer of the glass, and is then conducted inwards. This heating method is well controlled, and results in a smooth and contamination-free glass surface. Other heating methods, such as arc fusion or resistive heating, may leave tungsten, graphite, or metal oxide deposits on the spliced fiber surface. By contrast, with CO<sub>2</sub> laser splicing, the lack of surface irregularities and contamination enables remarkable spliced-fiber strength results, with some strength results nearly within the range of coated fiber breaking strength.