Incoherent Beam Combining of Continuous-Wave and Pulsed Yb-Doped Fiber Amplifiers

We review the technique of incoherent beam combining and show experimentally the combination of four continuous wave fiber amplifiers to an average power of 2 kW and four pulsed 2 ns fiber amplifiers to an average power of 187 W (pulse energy 3.7 mJ) using binary dielectric gratings. The scaling potential and limitations are discussed in detail.