High-power nanosecond ytterbium-doped fiber laser passively synchronized with a femtosecond Ti:sapphire laser

We report on laser synchronization between a high-power nanosecond fiber laser and an ultrashort Ti:sapphire laser by cross-absorption modulation and power amplification. The nanosecond pulses were generated by a long-cavity ytterbium-doped fiber laser that was passively synchronized to a 70 fs Ti:sapphire laser with a remarkable cavity mismatch tolerance of about 8 cm as a result of resonance-enhanced crossabsorption modulation in additional rare-earth-doped fiber. By using a two-stage Yb-doped fiber preamplifier and a two-stage double-clad fiber power amplifier in cascade, the synchronized nanosecond pulses were amplified to 131 W of average power, corresponding to 0.55 mJ of single-pulse energy at a repetition rate of 240 KHz, with a timing jitter of 13 ps.