【作者】 刘丹丹；

【导师】 张首刚；

【作者基本信息】 中国科学院研究生院（国家授时中心） ， 测试计量技术及仪器， 2010， 硕士

【摘要】 单模窄线宽的可调谐半导体激光器广泛应用于冷却原子、抽运原子态和原子激发荧光等,半导体激光器的应用是新型原子钟的特征。具有一定抗振能力,并能够在失锁时自动报警通讯,自动恢复原参数重新稳频工作是原子钟,尤其是保障空间原子钟长期可靠运行的关键。随着虚拟仪器技术的发展与普及,基于计算机的虚拟仪器应用越来越广泛。本论文提出将虚拟仪器应用于外腔半导体激光器数字自动稳频系统。首先介绍了半导体激光器稳频原理和基于原子饱和吸收谱线的激光稳频原理。利用铯原子D2线的饱和吸收峰频率作为参考频率,通过光电转换,利用比例加积分(PI)反馈控制将激光输出频率锁定在参考频率上的方法设计并实现了一套数字自动稳频系统。文章对实现的各个环节进行了详尽的分析研究。将整个系统分为温控系统模块、数据采集模块、数据处理模块,再细化分成功能单一的模块,然后对这些硬件和软件模块分别进行设计和调试。对外腔半导体激光器数字自动稳频系统的调试和测试结果表明该系统可以自动搜索铯原子D2线的饱和吸收峰,并将外腔半导体激光器的输出频率锁定到选定的饱和吸收峰上,在意外失锁后能自动恢复锁定。且具有一定的抗干扰能力,有良好的长期稳定性。文章最后对影响测量精度的主要因素进行了深入的分析。该系统人机界面友好,操作简单方便,参数容易修改和维护,已用于铯喷泉钟的实验研究中。更多还原

【Abstract】 A tunable diode laser with single mode and narrow linewidth is widely used in atom-cooling, pumping atomic, exciting atomic fluorescence and so on. The application of semiconductor diode laser is a new feature of new atomic clocks. Develop a robust external cavity diode laser (ECDL) is a key to assure atomic clocks especially space atomic clocks can run stably for a long period. This laser is insensitive to mechanical vibration and can give a warning signal when frequency of the laser is out of range, then relocked again.With the development and popularization of computer technology, the Virtual Instrument(VI) based on computer is applied more and more widely. The automatic digital frequency locking system with VI is presented in this paper. First, The principle of frequency stabilization of semiconductor is introduced. Then, we designed and realized a system to make the laser locked to the frequency of Cs atom absorption spectrum by PI feedback control. The strict research about all units of the ECDL automatic digital frequency locking system is presented in the paper. The entire system can be divided into several modules: temperature control module, data acquisition module, software interface module, data processing units. These units have been subdivided into single function parts, which are designed and tested respectively.We had tested the system with the ECDL. The result is that our system could lock the output frequency of the laser to the frequency of the any Cs absorption spectrum peak automatically and relock it quickly when the frequency of the laser is out of range. Moreover, it has ability of anti-inference and good performance of long time stability. Finally, the main factors which influence the precision of the system are analyzed in detail in this paper.This system has characters of good transformation and friendly human-machine interface. Meanwhile, it’s convenient to operate panel and modify parameter. Now, it has been used in the research of Cs atomic fountain clock.更多还原