Compact, all-solid-state, femtosecond Cr4+:YAG and Cr4+:forsterite las
ers have been demonstrated. In optimised cavities, self-starting of th
e mode-locking in Cr4+:YAG was observed generating pulse durations of
43 fs, while with Cr4+:forsterite, pulses as short as 68 fs were obtai
ned.