High peak power picosecond hybrid fiber and solid-state amplifier system

Abstract

We report the high peak power picosecond hybrid fiber and solid-state laser amplifier system. The passively mode-locked solid-state seed source produced an average power of 1.8 W with pulse width of 14 ps and repetition rate of 86 MHz. It was directly coupled into the first Yb-doped polarized photonic crystal fiber amplifier stage. To avoid the nonlinear effects in fiber, the output power from the first stage was merely amplified to 24 W with the narrow spectra broadening of 0.21 nm. For the improvement of the peak power, the dual-end pumped composite Nd:YVO4 amplifier system has been chosen at the second stage. To reduce the serious thermal effect, the thermally bonded composite YVO4 – Nd:YVO4 – YVO4 rod crystal was used as the gain medium. The 53 W TEM00 mode with the peak power of 40 kW, beam quality of M2 < 1.15, corresponding to the optical-optical efficiency of 42.4% was obtained at the hybrid amplifier laser system. The system allows using a low power seed source and demonstrates an increase in the peak power beyond a fiber master oscillator power amplifier's (MOPA's) limit.