Dual-wavelength single-longitudinal-mode sub-ns lasers with high pulse repetition frequency

A theoretical model suitable to the dual-wavelength electro-optical Q-switched laser was established. Based on the optimizations on the time-varying Q-switched loss, doped concentration of the gain medium, and transmission of the output coupler, 1 kHz 1064 nm and 532 nm single-longitudinal-mode pulse lasers both with sub-nanosecond pulse width (PW) were obtained. The measured PWs of the dual-wavelength lasers agreed well with the theoretical predictions. At a pump energy of 3.7 mJ, the PWs of the 1064 nm and 532 nm lasers were 0.97 ns and 0.61 ns, the single pulse energy of the two lasers were 0.55 mJ and 0.29 mJ. The beam quality factor, the energy fluctuation and the time jitter of the 1064 nm laser were 1.58, 0.000063% and 2.18 ps; and that of the 532 nm laser were 1.35, 0.000011% and 1.56 ps.