Optically pumped semiconductor disk laser with graded and step indices for cw and ultrashort pulse generation

Summary form only given. This paper reports continuous-wave (cw) and passive mode-locked laser operation of diode-pumped semiconductor disk lasers based on gain sections with step and graded index designs, each containing 6 InGaAs quantum wells. Mode-locked laser operation is achieved applying both structures, using a V-shaped cavity including a fast saturable semiconductor absorber mirror. Results show that the graded index structure exhibits clear advantages over the step index structure in cw-laser operation with respect to the saturation of the absorption. However, for mode-locked operation, shorter pulses are generated using the step index structure.