High-pulse-quality Yb-fiber amplifier generation of 10 μJ, 250 fs pulses at 500 kHz repetition rate

A high-pulse-quality femtosecond chirped pulse amplifier system based on tunable chirped fiber Bragg grating (CFBG) stretcher is reported. Dispersion of CFBG is fine-tuned designed to match the compressor. By controlling the dispersion of CFBG, net dispersion of the system approaches zero. Laser pulses with 10 μJ pulse energy and duration time of 250 fs after compression at a repetition rate of 500 kHz are obtained. The measured output energy fluctuation of root mean square is 0.3% in 1 h and the M2 factor is 1.07. These results indicate that the laser amplifier exhibits a great potential in industrial processing, military defense and scientific research.