Research On Performance And The Optical System Of Ultraviolet Imaging Spectrometer With Dispersion

Imaging spectrometers can acquire more information compared with spectrographs and imagers. It can gain the spectral information and image of the target at the same time, thus it can be used to analyze the component of the target, such as the atmosphere, coloring matter, plant and geology. Due to the characteristics of the UV band, the UV imaging spectrometer is more suitable for the substance analysis. But there is a problem that the power of UV band is low and is vanished easily. To improve the light efficiency, the concave grating is introduced. It can finish the dispersion of light and focusing, but the processing is complex, which makes it difficult for mass production. In this paper, we study the aberration theory and component of imaging spectrometer using plane diffraction grating.The characteristics of traditional imaging spectrometer is that the light of target is focused on the slit firstly, which is the first imaging, and is dispersed and imaged by spectrograph on the detector. The imaging spectrometer is separated to telescope objective and spectrograph, and the design of telescope objective is independent. On the aspect of the aberration theory, the aberration correction of the telescope objective and spectrograph is separated, thus there is no aberration on the slit. Based on the above, I think that the plane diffraction grating doesn’t introduced coma and astigmatism like the slit, and the grating can be regarded as the border.In my paper, I mainly studied the aberration theory and composition of the imaging spectrometer which is separated by the grating. The plane diffraction grating doesn’t participate in the aberration correction, which simplifies the calculation of aberration theory. The optical system of the new imaging spectrometer is composed of telescope and the imaging system, in which the telescope contains two parabolic mirrors and the imaging spectrometer contains two spherical mirrors. Based on the simulation with ZEMAX, the optical system works in 120~180nm, the spectral resolution is 1.3 nm, the size of the slit is 8mm×0.4mm, and MTF is larger than 0.3 at 35lp/mm.At last, I mainly studied the calibration and resolution the imaging spectrometer working in 240~360nm. The result shows that the uncertainty of the spectral calibration was not to exceed 0.407 nm, the uncertainty of the radiometric calibration was not to exceed ±7.5%, the spectral resolution is 0.98 nm, and the spatial resolution is 14.71g/mm,.