Swiderski, Jacek, et al. “A 2 ?M, Gain-Switched Tm-Doped Fiber Laser and Amplifier System With Output Average Power of 9 W at 50 KHz”. Photonics Letters of Poland, vol. 5, no. 3, Sept. 2013, pp. pp. 103-105, doi:10.4302/photon. lett. pl.v5i3.428.