Passively Mode-Locked Femtosecond Laser with Disordered Crystal Nd:CGA as Gain Medium*

We present a laser-diode-pumped passively mode-locked femtosecond disordered crystal laser by using Nd:CaGdAlO4 (Nd:CGA) as the gain medium. With a pair of SF6 prisms to control the dispersion compensation, laser pulses as short as 850 fs at 1079 nm are obtained with a repetition rate of 124.6 MHz. The measured threshold pump power is 1.45 W. A maximum average output power of 122 mW is obtained under the pump power of 5.9 W. These results show that Nd:CGA could be a promising laser medium for generating femtosecond ultrashort pulse at about 1 μm.