CsPbBr3 nanocrystal for mode-locking Tm-doped fiber laser**Project supported by the National Key R&D Program of China (Grant No. 2018YFB0504500), the National Natural Science Foundation of China (Grant Nos. 51472162, 51672177, and 61475171), and the Talent Introduction Research Project of Shanghai Institute of Technology, China (Grant No. YJ 2018-8).

Abstract

CsPbBr3 nanocrystal is used as the saturable absorber (SA) for mode-locking Tm-doped fiber laser in a ring fiber cavity. The modulation depth, saturable intensity, and non-saturable loss of the fabricated SA are 14.1%, 2.5 MW/cm2, and 5.9%, respectively. In the mode-locking operation, the mode-locked pulse train has a repetition rate of 16.6 MHz with pulse width of 24.2 ps. The laser wavelength is centered at 1992.9 nm with 3-dB spectrum width of 2.5 nm. The maximum output power is 110 mW with slope efficiency of 7.1%. Our experiment shows that CsPbBr3 nanocrystal can be used as an efficient SA in the 2- wavelength region.