SELF-STARTING SOLITON-MODELOCKED FEMTOSECOND CR(4-PEROT SATURABLE ABSORBER()YAG LASER USING AN ANTIRESONANT FABRY)

We set up a self-starting passively modelocked femtosecond Cr(4+):YAG laser using a low-finesse antiresonant Fabry-Perot saturable absorber (A-FPSA). Stable transform-limited pulses were produced without the cr itical cavity alignment necessary for Kerr lens modelocking. We achiev ed 114-fs pulses with 94 mW output power at the telecommunication wave length 1.5 mu m. The pulse formation is demonstrated to be due to soli ton modelocking. At higher intracavity energy multiple pulsing was obs erved and is explained by the saturation behaviour of the A-FPSA. In t he multipulsing regime a pulse width as short as 95 fs and an averaged output power of up to 395 mW have been obtained.