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 𝑀𝑥2 and 𝑀𝑦2 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.