基于倾斜场镜的C-T成像光谱仪优化设计

Optimization Design of C-T Imaging Spectrometer Based on the Tilt Field Len

残留谱线弯曲限制了切尔尼-特纳平面光栅光谱仪在成像光谱仪中的应用.本文不同于传统的基于棱镜的光栅谱线弯曲补偿方法,提出了基于倾斜场镜的补偿方法,即在校正场曲的同时对入射到场镜不同区域,不同波长的狭缝像分别进行谱线弯曲校正,且没有改变系统的其它光学特性.对狭缝大小为7.8mm×0.016mm、光谱范围0.31-0.5μm、光谱分辨率0.4nm、物方焦距70mm、1∶1放大倍率的切尔尼-特纳成像光谱仪进行了优化设计,结果全谱段、全视场MTF〉0.8,点列图RMS半径小于9μm,相对谱线弯曲小于0.2%,满足设计要求.实际设计表明该方法对于可选用光学玻璃有限,且能量较弱的紫外光学系统是一种可选的优化设计方法.

Residual smile limits the application of Czerny-Turner plane grating spectrometer in the imaging spectrometer.In this paper,different from the traditional method of smile correction based on prism,a method is proposed,which is based on the tilt field mirror.The field curve is corrected,at the same time,the different wavelength slit images in different regions of the field lens are corrected,and the other optical properties of the system are not changed.The Czerny Turner imaging spectrometer slit is 7.8millimeter length and 0.016 millimeter wide,spectral range from 0.31 to 0.5 microns,spectral resolution 0.4nanometers,the object focal length 70 millimeters,1∶1 magnification.Optimization design results,MTF over 0.8,RMS spot radius less than 9microns,the relative smile less than 0.2%,meet the design requirements.It shows that the method can be used in the systems with weak signal and low transmittance optical glass.