Single-walled carbon nanotube saturable absorbers were designed and fabricated for passive mode-locking of bulk lasers operating in the 2 mu m spectral range. Mode-locked lasers based on Tm:Lu2O3 single crystals containing different Tm3+-doping concentrations were studied. Nearly transform-limited pulses as short as 175 fs at 2070 nm were generated at 88 MHz repetition rate. (C)2012 Optical Society of Americ