An ultralow-threshold Kerr-lens mode-locked Ti:Al<sub>2</sub>O<sub>3</sub> laser achieved by use of an extended cavity design is demonstrated. Mode-locking thresholds as low as 156 mW are achieved. Pulses with durations as short as 14 fs and bandwidths of >100 nm with output powers of ~15 mW at 50-MHz repetition rates are generated by only 200 mW of pump power. Reducing the pump power requirements to a factor of 10× less than required by most conventional Kerr-lens mode-locked lasers permits inexpensive, low-power pump lasers to be used. This will facilitate the development of low-cost, high-performance femtosecond Ti:Al<sub>2</sub>O<sub>3</sub> laser technology.
© 2002 Optical Society of America
A. M. Kowalevicz, Jr., T. R. Schibli, F. X. Kärtner, and J. G. Fujimoto, "Ultralow-threshold Kerr-lens mode-locked Ti:Al2O3 laser," Opt. Lett. 27, 2037-2039 (2002)