Femtosecond Pulses near 2 μm from a Tm:KLuW Laser Mode-Locked by a Single-Walled Carbon Nanotube Saturable Absorber

Mode-locked laser operation based on a single-walled carbon nanotube saturable absorber is demonstrated in the 2 mu m spectral range using Tm-doped KLu(WO4)(2) as active laser medium. The mode-locked laser delivers pulses as short as 141 fs at a center wavelength of 2037 nm. The pulse spectrum encompasses about 100nm and the pulse duration is only 5% longer than the bandwidth limit. The oscillator operating at a repetition rate of 88MHz delivers 26mW average output power. (C) 2012 The Japan Society of Applied Physics