M. Müller, M. Kienel, A. Klenke, T. Gottschall, E. Shestaev, M. Plotner, J. Limpert, and A. Tünnermann, "1 kW 1 mJ eight-channel ultrafast fiber laser," Opt. Lett. 41, 3439 (2016).
An ultrafast fiber chirped-pulse amplifier comprising eight coherently combined amplifier channels is presented. The laser delivers 1 kW average power at 1 mJ pulse energy and 260 fs pulse duration. Excellent beam quality and low-noise performance are confirmed. The laser has proven suitable for demanding scientific applications. Further power scaling is possible right away using even more amplifier channels.