title: Single frequency MOPA based on Nd:YAG single crystal fiber and rods.
abstract: We demonstrate a single frequency 1064 nm master oscillator power amplifier (MOPA) system operating in macro-micro pulse scheme. The repetition rate for the macro pulses was 300 Hz with pulse duration of 300 μs. Micro pulses operated at 25 kHz. The master laser was a single-longitudinal-mode electro-optically Q-switched Nd:YAG laser with an output power of 250 mW and pulse duration of 33 ns. Three stages of power amplifiers based on Nd:YAG single crystal fiber and rods were designed. The final output power reached 31.3 W with pulse duration of 30 ns and linewidth of less than 130 MHz. Micro pulse energy of 13.9 mJ was obtained with a peak power of up to 464 kW. The beam quality factors (M2) were measured to be 1.56 and 1.76 in horizontal and vertical directions, respectively.
authors.forename: Zhaojun
authors.initials: Z
authors.lastname: Liu
authors.forename: Shaojie
authors.initials: S
authors.lastname: Men
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Cong
authors.forename: Houwen
authors.initials: H
authors.lastname: Yang
authors.forename: Wenyong
authors.initials: W
authors.lastname: Cheng
authors.forename: Han
authors.initials: H
authors.lastname: Rao
authors.forename: Jianren
authors.initials: J
authors.lastname: Lu
authors.forename: Xingyu
authors.initials: X
authors.lastname: Zhang