用于激光稳频的超低加速度灵敏度光纤干涉仪的实验研究
文献类型：学位论文
| 作者 | 胡永奇 |
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院上海光学精密机械研究所 |
| 导师 | 李唐 |
| 关键词 | 激光稳频 光纤干涉仪 光纤支架 有限元方法 全光纤环形谐振器 |
| 其他题名 | Research on Ultra-low Acceleration Sensitivity Optical Fiber Interferometer for Laser Stabilization |
| 中文摘要 | 本论文介绍了作者在超低噪声光纤干涉仪稳频激光器方面的研究，包括实现了稳频激光系统的搭建和超低噪声亚赫兹线宽激光的输出，以及为实验设计了超低加速度灵敏度光纤干涉仪支架。此外还介绍了利用全光纤环形谐振器实现对单频激光器频率噪声的抑制。 利用光纤干涉仪实现对激光频率的锁定，相比于其他的激光频率锁定方式，具有结构简单，环境敏感度较低，体积小，价格较低，方便对激光频率进行调节等方面的优势。在实验中，我与同事合作实现了将1550nm的激光锁定在外差式迈克尔逊干涉仪上，通过隔振、密封、控温等措施来降低外界环境的影响。在整个实验中我个人负责了光路的设计和搭建，以及温控电路的设计与焊接。最终我们通过比较测量两个相同的激光系统，测得激光的线宽为0.67Hz，其短期的频率稳定度为7x10-15（0.1-1s）。两台激光器的频率噪声功率谱密度在1Hz处小于-1dB Hz2/Hz，在200Hz到1kHz处达到-18 dB Hz2/Hz。 论文中也介绍了我所仿真设计的超低加速度灵敏度光纤干涉仪支架，利用这个支架可以大大减少机械振动噪声在光纤干涉仪稳频激光器实验中的影响。我们所设计的支架，其特点在于利用对称安装的结构，使得其垂直方向加速度灵敏度降低的同时，也可以通过优化支架参数得到水平方向上超低的加速度灵敏度。这相对于已提出的光纤支架是个很大的改进。利用有限元仿真计算，通过优化支架参数，最终得到我们所设计的支架水平加速度灵敏度达到3.25x10-12/g，垂直加速度灵敏度达到5.38x10-12/g。并且通过计算发现，这个对称安装结构的支架，对几何尺寸在一定的范围内不敏感。即可以大大减少仿真误差或加工误差带来的影响。 除此之外，论文还介绍了利用全光纤环形谐振器实现对单频激光器频率噪声的抑制。在实验中，采用Pound-Drever-Hall（PDH）的方法对锁定在铷原子吸收谱线上780nm的激光进行稳频，实现了饱和吸收光谱与光纤环形谐振器双回路锁定。通过外差式马赫-曾德干涉仪来测量锁定后的激光器频率噪声发现，在f<100Hz时，光纤环形谐振器对频率噪声的抑制度超过了40dB。在1Hz处，稳频激光器的频率噪声小于100 dB Hz^2/Hz，其抑制度达到60dB。 |
| 英文摘要 | This thesis presents the studies on the ultra-low noise fiber interferometer stabilized laser. Including the construction of two identical sub-hertz fiber-stabilized laser and the design of the ultra-low acceleration sensitivity fiber spool. Besides, the frequency noise suppression of single frequency laser by all-fiber ring resonator is also reported in the thesis. Compared to other traditional methods, all-fiber interferometer has the advantages of simple structure, low environmental sensitivity, small size, low price, and agile laser frequency tuning. In our experiment, the 1550nm laser is locked to a heterodyne Michelson interferometer. Many methods such as vibration isolation, acoustic damping, and active temperature control are used to reduce the impact of the external environment. Throughout the experiment, I personally responsible for the optical design and construction, as well as temperature control circuit design and welding. By comparing two identical laser systems, a 0.67 Hz linewidth beat-note signal is achieved and we obtain fractional frequency instability of 7 x 10?15 at short timescales (0.1–1 s). The frequency noise power spectral density of two identical lasers is below ?1 dB Hz2/Hz at 1 Hz and it reaches ?18 dB Hz2/Hz from 200 Hz to 1 kHz. The simulation and design of ultra-low acceleration sensitivity fiber spool is also reported. By using this fiber spool for laser stabilization, the vibration induced frequency noise will be dramatically reduced. Because of the symmetric mounting structure, the optic fiber spool could achieve ultra-low acceleration sensitivity both on the vertical and horizontal direction simultaneously by optimizing the parameter of the spool. By numerical analysis with finite element method, we obtain the optimal geometry parameters of the spool with which the horizontal and vertical acceleration sensitivity can be reduced to 3.25x10-12/g and 5.38x10-12/g respectively. Moreover, the structure features insensitivity to the variation of geometry parameters, which will minimize the influence from numerical simulation error and manufacture tolerance. Finally, we also report the principle and experimental results of laser frequency noise suppression by all-fiber ring resonator. A saturated absorption spectroscopy and fiber ring resonator double-loop-stabilization for laser frequency is realized by Pound-Drever-Hall（PDH）technique. We measure the frequency noise of stabilized laser by a heterodyne Mach-Zehnder interferometer and obtain the frequency noise suppression larger than 40 dB when Fourier frequency f<100Hz. At 1 Hz offset, the frequency noise power spectral density (PSD) of stabilized laser is less than 100 dB Hz2/Hz and the frequency noise suppression is 60 dB. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/16934]  |
| 专题 | 上海光学精密机械研究所_学位论文 |
| 推荐引用方式 GB/T 7714 | 胡永奇. 用于激光稳频的超低加速度灵敏度光纤干涉仪的实验研究[D]. 中国科学院上海光学精密机械研究所. 2015. |
入库方式： OAI收割
来源：上海光学精密机械研究所
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