A simple and efficientdiode-pumped Nd : YAG master-oscillator power-amplifier (MOPA) system is introduced. Themaster oscillator provides a pulse energy of 1. 13 J at a repetition rate of 100 Hz. Themaximum pulse energy of the MOPA system is 2. 35 J, and the corresponding totaloptical-to-optical efficiency is 39 ％. The experimental results are well agreed to the theoreticalcalculation.Xinjiang Uygur Autonomous Region Province, in 1968. He received the B. S. degree fromXinjiang Normal University in 1992 and M. Sc. degree from the Hebei University in 2003. Heis presently pursuing the Ph. D at Institute of Physics,CAS, and his research focuses onhigh-power diode-pumped solid-state lasers.Tel:010-82648093 Email:xjyxd@126.com杨晓冬（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080;嘉应学院,物理系,广东,梅州,514015）孙志培（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）毕勇（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）薄勇（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）耿爱丛（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）彭钦军（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）张恒利（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）崔大复（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）许祖彦（中科院物理研究所,北京凝聚态物理国家实验室,北京,100080）High Technology Research and Development Program of China (2002AA311120)