High-power diode-pumped actively Q-switched Nd:YAG laser at 1123 nm

A high-power diode-pumped Nd:YAG laser at 1123 nm is acousto-optically Q-switched at a pulse repetition rate range of 5-20 kHz. Experimental results reveal that the resonator mirrors need to suppress parasitic oscillations on lines in the 1064 nm as well as 1319 nm regions for actively Q-switching operation. With an incident pump power of 19.2 W, the pulse energy increases from 0.15 mJ at 20 kHz to 0.4 mJ at 5 kHz. The highest peak power is up to 8.0 kW at 5 kHz. Furthermore, a conventional model of coupled rate equations is used to analyze the experimental data. The general agreement indicates that the simple model is adequate for a first order prediction of the low-gain laser characteristics. (C) 2004 Elsevier B.V. All rights reserved.