Quasi-All-Fiber High-Efficiency Divided Chirp-Pulse Amplification System Based on Active Controlling

We present a new high-efficiency divided chirp-pulse amplification (DCPA) system based on an actively controlled quasi-all-fiber structure. As a proof-of-principle experiment, a two-channel amplification system composed of single-mode ytterbium-doped fiber is constructed. The experimental results show that the degree of linear polarization of ~93% is maintained after recombination and the system efficiency is up to ~95%. In addition, the beam quality (M2 factor) is around 1.2. Moreover, the system can operate stably for a long time without performance degradation. Compared with the traditional spatial DCPA, this system exhibits some advantages, such as improved spatial adjustment, high stability, compact size, and low cost. It is demonstrated that this work paves the way to design a quasi-all-fiber high-performance pulsed laser system.