声光可调谐滤波器成像光谱仪非球面光学系统设计

Aspheric Optical Design of an Imaging Spectrometer Based on Acousto-Optic Tunable Filter

基于声光可调谐滤波器(AOTF)的工作原理,设计了一套工作在440～780nm的光谱成像光学系统。该光学系统通过引入一面偶次非球面提高了系统的成像质量,简化了镜头的结构,提高了光学系统的透射率。前置光学系统采用由一组双胶合透镜构成的像方远心光路。后置成像光学系统由一组三胶合透镜构成,其中包含一面非球面,根据非球面变形系数与初级像差间的贡献关系,完成了非球面及其位置的优化和对AOTF的+1级衍射光成像。光学系统在32lp/mm的空间频率下的调制传递函数(MTF)大于0.6,像质优良,加工装调公差适中。

Based on the principle of acousto-optic tunable filter（AOTF）,the optical system of an imaging spectrometer is designed.The spectral range of the system covers 0.44~0.78 μm.An even aspheric surface is used to improve the imaging quality,optical transmissivity and simplify the lens structure.A telecentric optical arrangement is designed using a doublet lens for the fore-optical system.And for the rear imaging lens,a triplet lens is used which contains an aspheric surface.The aspheric surface and its location are optimized based on the primary aberrations theory of aspheric.The system takes the ＋1 order diffracted beams for imaging.The modulation transfer function（MTF） of the optical system is better than 0.6 at the spatial frequency of 32 lp/mm and the tolerance is moderate.