All passive synchronized Q-switching of a quasi-three-level and a four-level Nd:YAG laser

Using an all passive approach, synchronized Q-switching of two Nd:YAG lasers, at 946 nm and 1064 nm, is reported. Two laser crystals are used to avoid gain competition, and stable operation is reported for the first time. The pulse trains are synchronized over a wide range of pump powers and a relative timing jitter of 36 ns is achieved. A minimum delay of 64 ns is observed between the two laser pulses, and by making the 946 nm pulse relatively long, a 79% temporal overlap is obtained when compared to the zero-delay scenario.