17-µm Tm-fiber chirped pulse amplification system with dissipative soliton seed laser

We report on a 1.7 µm Tm-fiber chirped pulse amplification (CPA) system by virtue of a broadband dissipative soliton seed laser. The seed oscillator delivers the dissipative soliton with 10 dB spectral bandwidth of 23 nm and an average power of 4 mW. The duration of the seed pulse is directly stretched to ∼60ps by a segment of 50 m normal dispersion fiber. Using a two-stage fiber amplifier, the average power of the pulse is amplified to 1.95 W with a slope efficiency of 40.3%. The amplified pulse is then compressed to 348 fs by a pair of fused silica transmission gratings. The compressed average power of 1.3 W and peak power of 155 kW are achieved. These experimental results would pave the way to achieve a high-power femtosecond laser source at 1.7 µm, which could find important applications in fields such as three-photon deep-tissue imaging and material processing.