热光系数仪主要误差源及其抑制方法  

Main Error Sources and Suppression Methods of Thermal-Optic Coefficient Measurement Instrument

作　　者：梁松林[1] 张辉荣[1] 吴扬海 罗辉[1] 李斌[1] 郭春艳[1] 杨永强[1] 张祖邦 孙志成 Liang Songlin;Zhang Huirong;Wu Yanghai;Luo Hui;Li Bin;Guo Chunyan;Yang Yongqiang;Zhang Zubang;Sun Zhicheng(Southwest Institute of Technical Physics,Chengdu 610041,Sichuan,China)

机构地区：[1]西南技术物理研究所,四川成都610041

出　　处：《光学学报》2024年第13期118-127,共10页Acta Optica Sinica

摘　　要：为了精确测量光学材料的热膨胀系数和折射率温度系数,建立了基于马赫-曾德尔干涉光路的同步测试系统——热光系数仪,对其中存在的波形扭曲和零漂现象进行了详细分析,并给出了有效的解决方案,最终通过对石英玻璃样品的测试充分验证了该系统的高精度与可靠性。Objective When the optical materials generate heat or the ambient temperature changes, they often affect the normal working state of the optical systems. Thus, it is significant to master the thermal performance parameters of the materials for designing optical systems. Among the parameters, thermal expansion coefficient α and temperature coefficient of refractive index dn/d T are the two most commonly employed basic physical parameters. By measuring two of the three parameters including α, γ(temperature coefficient of optical path), and W(thermo-optic coefficient) using interference method, α and dn/d T can be deduced. There are various forms of optical route implementation, among which the “thermal-optic coefficient measurement instrument” based on the Mach-Zehnder(MZ) interferometer features a simple structure and free sample expansion, without additional clamping stress. Thus, we establish a set of instruments using this scheme, analyze the main error sources, and try to suppress or eliminate them. Finally, we conduct verification on quartz glass samples.Methods In the “thermal-optic coefficient measurement instrument”, the thermo-optic coefficients W can be measured from MZ interference results, and the temperature coefficient of optical path γ can be measured from the Fabry-Perot(FP)interference occurring between the sample end faces. Then α and dn/d T can be calculated from them. The optical path difference of FP interference is the optical path between the front and back surfaces of the sample, which is only related to the interior of the sample and is unaffected by other external factors, leading to high stability. However, the MZ interference optical path is influenced by many factors, including the FP interference effect in the sample, mechanical deformation outside the sample, and temperature drift. Therefore, the main error sources in this testing system are waveform distortion and zero drift phenomena in the MZ interference. Meanwhile, theoretical analysis shows that waveform distortio

关 键 词：热膨胀系数 折射率温度系数 干涉测量 零漂 

分 类 号：O436.1[机械工程—光学工程]