Mode-locked Yb:YAG lasers by using SHG nonlinear mirror

We have demonstrated a passively mode-locked Yb:YAG laser by using a second-harmonic nonlinear mirror (NLM) technique with a non-critical phase matched LBO crystal. Under cw Ti:sapphire laser pumping the device outputs Q-switched mode-locking (QML) pulse trains with an average output power of 844 mW and an optical conversion efficiency of 51%; the duration of an individual mode-locked pulse was determined as 9 ps. The possibility of high power sub-picosecond laser pulse generation in Yb:YAG under diode laser pumping is discussed.