Lasers emitting ultrashort optical pulses beyond 2 μm have found numerous applications in e.g. spectroscopy, telecommunications and medicine [1]. Such wavelengths typically can be reached by Ho-doped active fibers and broadband nanomaterials based saturable absorbers (SA) [2], which are recently intensively developed. Here, for the first time, we demonstrate a black phosphorus (BP) SA used as a mode-locker in an all-fiber Ho-doped laser. The generated solitons were centered at ∼2090 nm with FWHM of 4.2 nm and pulse duration of ∼1.3 ps.