自混合光腔衰荡技术测量高反射率研究

项目名称： 自混合光腔衰荡技术测量高反射率研究

项目编号： No.60878038

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 电工技术

项目作者： 李斌成

作者单位： 中国科学院光电技术研究所

项目金额： 36万元

中文摘要： 高反射率反射镜的广泛应用和高反膜性能的不断提高，使高反射率准确测量的需求日益迫切。而传统的基于分光光度和比值法的反射率测量技术无法准确测量反射率高于99.99%的高反射薄膜元件。实验建立了基于连续半导体激光器自混合效应的光腔衰荡技术高反射率测量实验装置，讨论了直腔和折叠腔不同反馈光强度和频谱特征时，自混合效应对半导体激光器输出频谱和功率的影响，对比分析了直腔和折叠腔输出信号中共振尖峰的形成机理、幅值及时域特性。实验测量了1064nm波长高反镜反射率，分析了自混合光腔衰荡技术用于高反射率测量的重复性测量精度。利用Labview虚拟仪器软件编写了实验系统的计算机控制程序，实现了高反射率测量系统的计算机控制和数据采集处理自动化。分析了在利用该装置测量大口径光学元件反射率时，样品自动扫描过程中的角度失调对测量结果的影响。利用本项目积累的光腔衰荡技术理论和实验条件，开展了光学元件消光系数的测量实验以及痕量气体检测实验研究，并取得了较好的测量结果。

中文关键词： 光腔衰荡；自混合效应；高反射率；反馈光

英文摘要： The accurate measurement of a high reflectivity is very important as the high-reflectivity (HR) mirrors has been widely used in many large laser systems and the performance of the HR coatings has been greatly improved. Reflectivity higher than 99.99% cannot be precisely determined by conventional techniques, which are based on spectrophotometry or laser ratiometry. The self-mixing cavity ring-down （CRD） technique based on continous wave diode laser is employed for HR measurement. Two optical feedback (OF) schemes (linear and folded cavity schemes) for the OF-CRD technique are compared in both wavelength- and time- domains. Due to the difference in the strengths and spectra of the OF, the appearance frequencies and amplitudes of the resonance peaks in the CRD signals in both schemes differ significantly. Based on these two OF-CRD schemes, simple and low-cost high reflectivity measurement apparatuses are established in Labview environment and high-accuracy measurements of high reflectivity are experimentally achieved.In the OF-CRD technique for measuring the high reflectivity of large-aperture laser optics, the angular misalignment of the test optics, which is induced by the scanning mechanical parts, influences the measurement accuracy.The influence of the angular misalignment of the large-aperture component on the measurement results are also analyzed. Additionally, the total optical losses of optical components are also measured by the OF-CRD setup, and trace gas detection is achieved based on CRD technique. This study demonstrates the feasibility of CRD technique on the application of high reflectivity measurement,optical loss measeurement and trace gas monitoring, and provides theoretical and experimental basics for instrumentation of the CRD technique.

英文关键词： Cavity ring-down; Self mixing effect; High reflectivity; Optical feedback