空间外差干涉光谱仪仪器线型函数测量新方法研究

Study on a New Method for Instrumental Line Shape Measurement of Spatial Heterodyne Interference Spectrometer

空间外差干涉光谱技术是近年发展起来的新型静态超分辨光谱分光技术,仪器线型函数是其基本性能参数之一,代表了仪器的光谱分辨能力,需要精确表征。在分析仪器线型函数影响因素(切趾、有效视场角与离轴像元效应)以及测量方法与测量光源等特殊性要求基础上,提出了一种可调波长单色面光源的全新测量方法,并利用可调谐激光器与消散斑积分球等设备搭建了测量实验装置。在仪器线型函数测量实验中,通过选取光谱范围内的典型谱段进行高光谱(0.1nm步长)扫描,经过干涉数据误差修正、光谱复原以及坐标归一化等数据处理过程,获取了仪器线型函数的能量分布形式。此外,利用全光谱范围内扫描的干涉数据,得到仪器线型函数的全峰半宽随波长的变化规律曲线。最后,将本方法获取的实测仪器线型函数与模拟光谱(LBL计算)进行卷积获取理论谱,并与地基探测实验获取的实测大气CO2吸收光谱进行比对分析,两者吻合一致,验证了本方法获取的仪器线型函数具有较高的精度。

Spatial heterodyne spectroscopy （SHS）is a novel method for hyper-spectral analysis ,and instrument line shape function is one of the basic performance parameters ,which should be precisely characterized .Based on the analysis of the influence factors（apodization ,limited angle ,abaxial detector element ） and special requirement for measuring method and source ,the present paper put forward a new method for measuring with tunable monochromatic light source ,and designed experimental equipment with tunable laser and integrating sphere eliminating speckle .Selecting typical spectral range within band range for high spectral resolution scanning （0 .1nm step） ,the energy distribution of spectrum was obtained according to error correction , spectral reconstruction and normalization .In addition ,rule curve for FWHM and wavelength was obtained by the full spectral range scanning interferogram . Finally , theoretical spectrum , ILS convolution simulated spectrum （LBL calculated ） , and measured carbon dioxide absorption spectrum by ground-based experiment are in good agreement .The result shows that the instrument line shape function exhibits high accuracy .