中波/长波双色多视场光学系统设计

The design of MWIR/LWIR multiple FOV optical system

设计了一种基于中/长波双色焦平面阵列探测器的红外多视场变焦距光学系统,通过在窄视场光路中插入不同镜组的方式实现宽、中、窄视场的转换,并利用谐衍射原理和非球面设计进行像差平衡,其工作波长范围为中波3～5μm、长波7.7～9.5μm,F数为3,变倍比达到18∶1.设计结果表明,在中长波双色工作模式下,中长波各个视场的MTF均接近衍射极限、中波红外70%的能量分布在一个探测器像元内、长波红外60%的能量分布在一个探测器像元内、温度适应性好.该双色多视场光学系统在军民用光电探测领域有重要作用和广阔的市场前景.

The design of an infrared multiple FOV optical system with a MWIR/LWIR dual-band staring focal plane ar- ray detector was introduced. Wide medium narrow FOV was realized by inserting different sets of lens groups in narrow optical path. The harmonic diffraction theory and aspheric design method were used in the aberration balance. The oper- ating wavelength region is 3 to 5 μm and 7.7 to 9.5 μm, F-number is 3, and zoom ratio is 18： 1. The results indicate that the modulation transfer functions （MTF） of all FOV are approaching to diffraction limit, 70 percent medium-wave infrared encircled energy and 60 percent long-wave infrared encircled energy are concentrated in one pixel of detector. Moreover, it could obtain well optical performance in all temperature range. The dual-band optical system could be widely applied in military and civilian opto-electronic detective fields.