  We report a 2\mu m ultrafast solid-state Tm:Lu2O3 laser, mode-locked by
single-layer graphene, generating transform-limited~410fs pulses, with a
spectral width~11.1nm at 2067nm. The maximum average output power is 270mW, at
a pulse repetition frequency of 110MHz. This is a convenient high-power
transform-limited laser at 2\mu m for various applications, such as laser
surgery and material processing.
