Simultaneous Raman based Power Combining and Wavelength Conversion of High-power Fiber Lasers

We present a technique for simultaneous power-combining and wavelength-conversion of multiple fiber lasers into a single, lower wavelength in a different band through Raman-based, nonlinear power combining. We illustrate this by power combining of two independent Ytterbium lasers into a single wavelength around 1.5micron with high output powers of upto 99W. A high conversion efficiency of ~64% of the quantum limited efficiency and a high level of wavelength conversion with >85% of the output power in the final wavelength is demonstrated. The proposed method enables power-scaling in various wavelength bands where conventional fiber lasers are unavailable or limited in power.