Energy efficiency of fiber lasers

The technology of laser cutting has been the basic technology for cutting metal sheets in the industry for several decades. The development of laser cutters made it possible to discover the possibility of amplifying light using the phenomenon of forced emission.

The first lasers used to cut metals were gas, molecular lasers based on an active medium which was carbon dioxide -CO2. These lasers are characterized by the possibility of obtaining high powers, which allowed them to be used for processing metals. The first CO2 lasers were characterized by relatively low efficiency, not exceeding 2-3%. Over the years, scientists have managed to increase the efficiency calculated in relation to the power taken from the mains to about 10% thanks to the optimization of projects and the availability of more and more perfect materials. Despite the fact that for lasers it is a relatively high value, from the point of view of operating costs of using a laser cutter, electricity consumption is an important part of it.

            Scientists trying to find another type of high-power lasers that would be suitable for cutting metals became interested in semiconductor lasers, the development of which in recent years has been very dynamic due to the worldwide demand for semiconductor light sources. Thanks to their work, in recent years, new possibilities have been discovered to create lasers in which the active medium is a doped fiber core pumped by the above-mentioned semiconductor lasers. The efficiency of light processing in active optical fiber reaches 70%, which in combination with the efficiency of semiconductor laser pumps at the level of 50% gives the resultant efficiency from the power socket at the level of over 30%.

            For example, a CO2 laser source with an output power of 4kW consumes approx. 40kW, while a fiber laser source of the same power consumes approx. 13kW. The comparison of these technologies shows that the energy efficiency of fiber lasers is 200% higher than the CO2 lasers used to date. This has a significant impact on savings resulting from the reduction of electricity consumption, and thus the reduction of greenhouse gas emissions.