紧凑型空间外差成像光谱仪设计

Design of Compact Spatial Heterodyne Imaging Spectrometer

设计了一种适合微小卫星平台应用的紧凑型空间外差成像光谱仪,该系统利用两套干涉结构将干涉条纹定域于系统外部,并将前置透镜的成像面与系统干涉面重合以获取目标的空间位置信息和光谱信息.根据系统轴上光表达式和奈奎斯特采样定律,给出了系统光谱分辨率和光谱范围与元件参数的匹配关系.通过光线追迹的方式,理论证明了干涉图定域位置,并推导了普适仪器函数表达式.针对氧原子气辉(O[1 D]630nm)星载测量,完成了该紧凑型空间外差成像光谱仪的系统设计和仿真,系统光谱采样间隔为0.762 3cm-1,光谱范围为601.674 9~631.324 6nm.最后通过搭建实验装置获取632.8nm激光光源的目标图像和复原光谱.仿真和实验结果表明:系统光谱采样间隔达到设计要求,且光谱分辨能力为20 822(@630nm);λ/4波长和线偏振器的装调误差(±1°)对系统干涉图调制度影响很小.该系统具有成像能力和光谱探测能力,可作为一种时空联合型干涉光谱仪使用.

A compact spatial heterodyne imaging spectrometer suitable for micro satellite platforms is designed.Two sets of interference structures are used to make the fringes localized outside the system.The imaging plane of front lens system and fringe localization of system are overlapped so that the spatial location information and the spectral information of target are obtained.According to the expression of axis optical field and Nyquist sampling theorem,the relationship between spectral resolution and spectral range and some critical parameters is given.Through the way of ray tracing,the theoretical proof of fringe localization is described in detail,and the universal function expression of instrument is derived.This compact spatial heterodyne imaging spectrometer for observation of O[1 D]630 nm airglow from satellite is designed and simulated.The spectral sampling interval of the system is 0.762 3 cm-1 and the spectral range is 601.674 9 ~631.324 6 nm.Finally,a compact spatial heterodyne imaging spectrometer is built to verify the results.And the target image and recovery spectrum of the 632.8 nm laser source is obtained.The simulation and experimental results show that spectral sampling interval of the system achieve the design requirements,and the spectral is 20 822 at 630 nm.The alignment error（±1°）of quarter-wave plate and polarizer has little influence on the modulation of fringes.It shows that the system has the imaging capabilities and spectral detectability,and can be used as a spatiotemporal mixed modulated spectrometer.