Advances in High Power Beam Combinable Fiber Lasers

High power beam combinable fiber lasers are basic modules for developing high power beam-combined fiber laser system such as coherent beam combining and spectral beam combining, in which narrow-linewidth operation are their essential property. In the present talk, we will review the research progress on high power beam combinable fiber lasers, then we will demonstrate our recent progress in our group: we have achieved a 4 kW level narrow-linewidth fiber laser based on tandem pumping scheme, which is the power record of beam combinable fiber lasers to the best of our knowledge. The spectral linewidth account for 90% power is ~ 0.89 nm at full power.