The stretched pulse has narrower pulse duration and high pulse energy than conventional soliton, so that the stretchedpulse can improve the potential application values of 2 μm mode-locked fiber laser in remote sensing, mid-infraredsource, material processing and other applications. In this paper, the dispersion management method is adopted toaccurately manage the dispersion in the cavity using a commercial ultra-high numerical aperture fiber and a commonsingle-mode fiber. Based on the nonlinear polarization rotation technology to achieve mode-locking, when the pumppower is set to 645 mW, the polarization controller is adjusted to achieve stretched pulse output with a de-chirped pulseduration of 581 fs. The center wavelength is 1939.26 nm and the 3-dB bandwidth is 21.8 nm. The repetition rate is 28.9MHz and the signal to noise ratio is 54.21 dB. At the maximum pump power, the direct output power of the resonantcavity is 9.98 mW, and the corresponding single pulse energy is 0.34 nJ.
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