为了解决现有的光学系统在机载等领域中的局限性,引入自由度比较丰富的光学自由曲面,设计了一个小F数、大视场、较轻便的机载中波红外离轴两反光学系统.采用反射式的光学系统并通过离轴方式消除光线遮拦,通过XY多项式表达的自由曲面,运用前6阶项有效地平衡了高级像差.最终得到一款焦距为240mm,视场角为3.8°,F数为3的中波红外光学系统,在全视场范围内系统的调制传递函数(Modulation Transfer Function,MTF)接近衍射极限,各视场的弥散斑均方根(Root Mean Square,RMS)半径在单个探测器像元尺寸15 μm以内,整体物理尺寸小于130mm(X)×180 mm(Y)×240mm(Z).最终结果表明,该系统在满足成像质量的同时,其结构简单,轻便性较好,可广泛应用于机载对地侦察成像等领域中.
Design of Airborne Mid-Wave Infrared Off-Axis Two-Mirror Optical System
In order to solve the limitations of existing optical systems in airborne and other fields,optical free-form surfaces with rich degrees of freedom are introduced to design a small F number,large field of view,and lighter airborne mid-wave infrared off-axis two-mirror optical system.The reflective optical system is adopted to eliminate light occlusion by off-axis,and the free-form surface expressed by XY polynomials effectively balances the advanced aberrations by using the first 6 terms.Finally,a medium-wave infrared optical system with a focal length of 240 mm,a field of view angle of 3.8° and an F number of 3 is obtained,and the system's Modulation Transfer Function(MTF)is close to the diffraction limit in the full field of view,and the radius of the Root Mean Square(RMS)of each field of view is within 15 μm of the cell size of a single detector,and the overall physical size is less than 190 mm(X)×190 mm(Y)×240 mm(Z).The final results show that the system not only meets the imaging quality,but also has simple structure and good lightness,and can be widely used in airborne ground reconnaissance imaging and other fields.
airborneoff-axis two-mirrorfreeform surfacessmall F numberXY polynomials
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维普
