研制了一台LD侧面泵浦和腔内和频结构的小型全固态589 nm激光器, 报道了利用该激光器激发钠导星亮度的实验研究结果。通过数值模拟分析并设计了谐振腔腔长、晶体位置等, 使其具有体积小、转换效率高等特点。研制了一套时域匹配电源用于补偿两路激光脉冲的时间差。对分束镜双侧进行特殊镀膜, 获得了相应的线偏振光并提高了转换效率和热稳定性。采用插入标准具、特殊镀膜等技术抑制了1 338 nm谱线的振荡。最后设计了相应的发射望远镜和接收系统用于钠激光导星的观测。测试结果表明, 该激光器的输出功率大于8 W, 重复频率为5 kHz, 线宽小于3.5 GHz, 对应808 nm泵浦功率的转换效率达到2%。在长春市内天光背景下, 冬季实验激发的导星亮度可达10.0等。

A LD side-pumped 589 nm small-scale all-solid-state laser with an intra-cavity sum-frequency structure was developed and the experiments for exciting the brightness of a sodium guide star by the laser were described. The numerical simulation method was employed to analyze and design the cavity length and the position of a sum-frequency crystal, and it shows a smaller size and higher conversion efficiency. A synchronous power system in time domain was developed to compensate the delay between pulses of the two fundamental lasers. Special films were coated on the sides of the splitter mirror to obtain linear polarized laser as well as to increase the conversion efficiency and the thermal stability. Moreover, etalons and special coating methods were employed to suppress the oscillation of 1 338 nm spectral line. Finally, a dedicated launch telescope and a receive system were used for the generation and observation of sodium guide star. Test results show that the laser offers an output power more than 8 W, a repetition frequency of 5 kHz and the linewidth less than 3.5 GHz, meanwhile, its conversion efficiency is up to 2% corresponding to the 808 nm pump power. Under the sky background light of Changchun, the brightness of the guide star excited by the laser in winter experiments is about 10 Mv.