Low-Loss Quantum-Dot-Based Saturable Absorber For Efficient Femtosecond Pulse Generation

We report the efficient generation of femtosecond pulses from a diode-pumped solid-state laser that has been passively mode locked using a quantum-dot-based saturable absorber. Average output powers up to 1.15 W and transform-limited pulses as short as 114 fs were obtained around 1040 nm with a pulse repetition frequency of 107 MHz from a diode-pumped Yb3+:KY(WO4)(2) laser. The InGaAs quantum-dot saturable absorber was characterized to have a saturation fluence of 25 mu J/cm(2) and nonsaturable losses of less than 0.2% with an initial low-signal absorption of 2.5% at 1040 nm.