High efficiency kilowatt-class fiber laser

We propose to develop a kilowatt fiber laser that is highly efficient at the conversion of electrical power into a diffraction-limited laser beam. The overall goal of this program is to deliver an unprecedented kilowatt-class fiber laser. The laser will becompact in size and light in weight. The goals of the Phase I are all accomplished or exceeded ahead of time. The feasibility of the proposed fiber laser is fully demonstrated. The newly developed beam shaping technology showed the capability to injectkilowatt or even multi-kilowatt pumping power into small laser fiber aperture. In particular, novel fiber-cladding geometry were thoroughly studied, showing the high-efficiency and feasibility for high-power operation.. A fiber laser device was also madefor commercial laser fiber evaluation. A solid foundation for further development has been provided by the successful Phase I program. In Phase II, a prototype fiber laser with ~1kW CW power will be constructed based on the outstanding results of Phase I.The record-breaking fiber laser will have the following characteristics:1. Fiber laser output power ~1 kW2. Operation mode: CW3. Beam quality M2 factor <1.14. Center wavelength : 1.09¿Im