大工作距大相对孔径高分辨率的改进型Dyson光谱成像系统设计

基于反/折射球面罗兰圆建模和宽波段Dyson象散校正方法,解释了大相对孔径高光谱分辨率的Dyson光谱成像系统存在的大工作距设计难题。从工作距的角度,比较了已有文献中报道的三种Dyson光谱成像系统改进思路。在大工作距要求下,采取第一种思路,即在传统型Dyson光谱成像系统结构基础上,引入球面弯月透镜和平面-非球面透镜。建立了平面-非球面校正透镜的三阶像差模型,给出了改进型Dyson光谱成像系统。设计结果表明:改进型Dyson光谱成像系统具有12mm工作距,F/1.8相对孔径,在0.38~0.9μm谱段范围内光谱分辨率约为0.45nm,以及接近衍射极限的优良成像性质,MTF在全波段全视场100lp·mm~(-1)线处大于0.7,最大像面均方根值半径小于1.2μm。同时,系统的Smile(谱线弯曲)和Keystone(色畸变)得到了很好的控制,保证了获取光谱数据的一致性。改进型Dyson光谱成像系统具有大相对孔径和高光谱分辨率的特点,而且系统焦平面探测器和系统入射狭缝两者的彼此间隙位置合适,易于装配。解决了传统型Dyson光谱成像系统实际应用中工作距不足的问题,可为大气遥感、农林调查、海洋生物等领域的高光谱成像信息探测提供一个新型的高光谱成像系统,对光谱成像系统的发展具有良好的促进意义。

Optical Design of Large Relief Large Relative Apertureand High Resolution Modified Dyson Imaging Spectrometer

We present the optical design of modified Dyson imaging spectrometer (MDIS) ,to get a fast F# and high resolution ability under the large focal planerelief ,ameniscus lens and a plano-aspherical lenswere added into classical Dyson construction consisting of Dyson lens and concave grate .Firstly ,MDIS can solve the defects that the detector and slit are hard to be arranged in a classical Dyson imaging spectrometer .Moreover ,under the large focal plane reliefconstraintsimposed by assembling and work environment ,MDIS is an F/1.8 and spectral resolution 0.45 nmdesign ,covering the spectral range 0.38~0.9 μm .Sec-ondly ,to our knowledge this is the first time that a fast and high spectral resolution Dyson design is under 12 mm focal plane re-lief .Although the simplicityof the classical Dyson construction is weakened ,MDIS has a very good practical value .Specifically , MDIS can realize the function of a relay imaging system with a 12 mm slit length as well as 250 mm × 92 mm × 92 mm system size .The design result showed that image quality close to the diffraction limit has been obtained .That is ,the value of MTF at all working wavelengths in all fields was greater than 0.7 at 100 lp · mm -1 ;the maximum of the keystone and the smile at all working wavelengths in all fields were respectively 1 and 0.7 μm .Finally ,we can say MDIS provides an effective way to detect atmospheric remotesensing ,agriculture ,forestry and marine organismsinformation and so on .