Hundred-watt-level 1 030 nm fiber-bulk hybrid amplified laser

Fiber-bulk hybrid amplification technology combines the advantages of fiber lasers and bulk amplifiers to obtain a compact and low-cost high power ultrashort pulse laser. Therefore, a high average power ultrashort pulse laser was designed based on Yb-doped fiber-bulk hybrid amplification technology. The laser was consisted of an Yb-doped all-fiber laser and two-stage bulk amplifiers. The first bulk amplifier was based on Yb: YAG single crystal fiber, and the second bulk amplifier was based on Yb: YAG rod with unpolished barrel. The all-fiber front end delivered 6.5 W average power, 52.9 MHz repetition rate and 47.5 ps pulse duration. The single crystal fiber amplifier obtained an average power of 40 W at the backward pump power of 182 W through a single-pass amplification. The Yb: YAG rod amplifier outputted an average output power of 122.9 W at the backward pump power of 307 W in single-pass configuration. After removing the depolarization part introduced by thermal effect, an average output power of 107.3 W with linear polarization state was obtained, and the corresponding slope efficiency was 26.1%. The pulse width of 12.1 ps and center wavelength of 1030.6 nm with spectral width of 2.4 nm were achieved. At the maximum output power of 107.3 W, a beam quality factor of 1.45 and 1.20 were measured along the vertical and horizontal direction, respectively.