Generation of sub-100-fs pulses from a cw mode-locked chromium-doped forsterite laser

Generation of femtosecond pulses from a continuous-wave mode-locked chromium-doped forsterite (Cr (4+):Mg(2)SiO(4)) laser is reported. The forsterite laser was actively mode locked by using an acousto-optic modulator operating at 78 MHz with two Brewster high-dispersion glass prisms for intracavity chirp compensation. Transform-limited sub-100-fs pulses were routinely generated in the TEM(00) mode with 85 mW of continuous power (with 1% output coupler), tunable over 1230-1280 nm. The shortest pulses had a 60-fs pulse width.