Fiber Lasers V: Technology, Systems, and Applications

High-power fiber lasers and amplifiers have gained tremendous momentum in the last five years, and many of the traditional manufactures of gas and solid-state lasers are pursuing the attractive fiber-based systems, which are now displacing the old technology in many areas. High-power fiber laser systems require specially designed fibers with large cores and good power handling capabilities – requirements that are all met by the airclad fiber technology.

In the present paper we go through many of the building blocks needed to build high-power systems and we show an example of a complete airclad laser system. We present the latest advancements within airclad fiber technology including a new 70 μm single-mode polarization-maintaining rod-type fiber capable of amplifying to MW power levels.

Furthermore we describe the novel airclad based pump combiners and their use in a completely monolithic 350 W CW fiber laser system with an M2 of less than 1.1. Finally, we briefly touch upon the subject of photo darkening and its origin.