A compact femtosecond laser system based on homemade Yb:YAG single crystal fiber gain module with high pulse energy and good beam quality

In this research work, we demonstrated a fiber-solid state hybrid chirped pulse amplification (CPA) laser system with high pulse energy and good beam quality based on homemade Yb:YAG single-crystal-fiber (SCF) gain module. An all-fiber front end could output an average power of 5 W at a reoetition of 500 kHz. For the first-stage SCF amplifier, we utilized high-brightness laser-diode (LD) to obtain an average power 34.5 W. For the second-stage SCF amplifier, we also utilized high-brightness LD to obtain an average power 71 W. The 𝑀_𝑥² and 𝑀_𝑦² were 1.26 and 1.25, respectively. Finally, we obtained the ultrafast laser output with an average power of 51 W, a pulse energy of 102 μJ and a pulse duration of 573 fs after pulse compression.