Phase locking for two ytterbium-doped large-core fiber lasers has been demonstrated by using a self-imaging confocal resonator with a spatial filter. Steady high-contrast interference stripes are observed. The visibilities of coherent and incoherent stripes are 59% and 6%, respectively. The measured width of the central strip is in good agreement with the calculated result. For in-phase mode, the output power of the phase-locked fiber laser array is up to 113 W and corresponding slope efficiency is 38.5%.
© 2007 Chinese Optics Letters
(030.1670) Coherence and statistical optics : Coherent optical effects
(060.2320) Fiber optics and optical communications : Fiber optics amplifiers and oscillators
(070.6110) Fourier optics and signal processing : Spatial filtering
(140.3290) Lasers and laser optics : Laser arrays
Bing He, Qihong Lou, Jun Zhou, Yinghui Zheng, Dong Xue, Jingxing Dong, Yunrong Wei, Fangpei Zhang, Yunfeng Qi, Jianqiang Zhu, Jinyan Li, Shiyu Li, and Zhijiang Wang, "113-W in-phase mode output from two ytterbium-doped large-core double-cladding fiber lasers," Chin. Opt. Lett. 5, 412-414 (2007)