强度调制偏振光谱仪的系统设计

System design of intensity modulation spectropolarimeter

理论分析和实验研究了强度调制偏振光谱仪系统参数的设计。介绍了强度调制偏振光谱仪的结构原理,分析了调制器设计、光谱仪选型与系统指标间的匹配关系。给出了一个完整的设计实例,以搭台方式建立了强度调制偏振光谱仪原理实验装置,并对平行光管直接输出的光和经起偏器起偏后输出的光进行了偏振光谱测量和分析。结果表明:在有效测量波段内(525～700nm),以卤钨灯为光源的平行光管直接输出光的偏振度值<10%;经过线偏振器起偏后输出光的偏振度值接近100%,与理论分析的结果一致,验证了基于强度调制技术设计偏振光谱仪方法的可行性。

The parameter design of a Intensity Modulation Spectropolarimeter（IMS） was studied and analyzed in this paper. The basic concept and structure of the IMS were described and the dependence on modulator design, spectrometer selection and system performance was analyzed. By taking an integrated system design for an example,the IMS experimental system was established in the laboratory, the basic concepts and characteristics of the technique were verified and the polarization spectra from a typical light source were also tested. Experimental results show that the polarized degree of the light from a tungsten-halogen lamp collimator is less than 10%, but it is about 100% when the light is polarized by a polarizer in the spectral range of 525-700 nm. These results are coincident with the theoretical results well, which verifies the feasibility of method that speetropolarimeter can be realized based on the intensity modulation.