Generation of high-energy pulses in dispersion-managed Tm-doped fiber laser

An dispersion-managed thulium(Tm)-doped fiber laser was designed and demonstrated. By adjusting the pump power and the intracavity polarization state, the stable stretched-pulse can be firstly achieved. The center wavelength of stretched-pulse is 1 939.4 nm and the pulse width is 482 fs. The maximum output power of stretched-pulse is 15 mW, and the corresponding single pulse energy is 0.52 nJ. When increasing the pump power to 645 mW, the noise-like pulse can be realized with appropriately adjusting the polarization controller, and the center wavelength is 1 940.1 nm. The mode-locked pulse achieved has femtosecond(fs)-order spike and picosecond(ps)-order pedestal. The maximum output power of noise-like pulse is 20.4 mW and the corresponding single pulse energy is 0.7 nJ. Compared to traditional soliton, the mode-locked pulses achieved under dispersion management have higher pulse energy. In addition, the designed Tm-doped fiber laser can be used as the seed source of the main oscillation power amplification and chirped-pulse amplification structure for improving the pulse energy and further expanding the practical applications of the 2 μm high energy fiber laser.