Mode locking of an Yb-doped bulk laser in the $1\mu \mathrm{m}$ spectral range using a single-walled carbon nanotube saturable absorber (SWCNT-SA) is demonstrated for the first time, to our knowledge. Passive mode locking of an Yb:KLuW laser resulted in nearly transform-limited pulses as short as $115\mathrm{fs}$ at $1048\mathrm{nm}$. In addition, the nonlinear response of the SWCNT-SA was measured, yielding a modulation depth of 0.25% and a relaxation time of $750\mathrm{fs}$.

Stable and self-starting mode-locking of a Tm:KLu(WO4)2 crystal laser is demonstrated using a transmission-type single-walled carbon nanotube (SWCNT) based saturable absorber (SA). These experiments in the 2 µm regime utilize the E₁₁ transition of the SWCNTs for nonlinear saturable absorption. The recovery time of the SWCNT-SA is measured by pump-probe measurements as ~1.2 ps. The mode-locked laser delivers ~10-ps pulses near 1.95 µm with a maximum output power of up to 240 mW at 126 MHz repetition rate.