摘要
为提高机载短波红外(SWIR)推扫式成像光谱仪遥感工作效率,获取更大的地面覆盖宽度,对视场角(FOV)达到90°的超广角前置光学系统进行了研究。针对传统折射式短波红外(1～2.5μm)系统在长波端透射率低的问题,提出了采用新型偏轴反射型式进行前置光学系统设计的思路。归纳了矢量像差理论所描述的控制偏轴系统三阶像差的方法。通过初始结构求解,在优化中控制像方远心及畸变,设计了焦距15mm、相对孔径1/3.5、视场角达到90°的偏轴反射式前置光学系统,在奈奎斯特频率处的平均调制传递函数(MTF)优于0.68,边缘视场的相对照度达到88%,且不存在材料吸收引起的透射率下降问题。同时对畸变影响下的推扫图像也进行了仿真。该光学设计应用于大视场短波红外成像光谱仪,可极大地提高系统的探测灵敏度。
To increase working efficiency of airborne short wave infrared （SWIR） push-broom spectral imagers and acquire wider coverage, a fore-optics with 90° field of view （FOV） is researched. A new-style tilted component reflective system is put forward to avoid descending of transmittance at long waveband in traditional refractive SWIR fore-optics working in 1 - 2. 5 μm. Three-order aberrations correction of tilted component system is briefly introduced. Based on initial configuration solving, a 15 mm focal length, 1/3.5 relative aperture, 90° FOV reflective fore-optics with tilted components is designed, whose distortion is optimized while remain telecentric. Its average modulate transfer function （MTF） at Nyquist frequency is more than 0.68, and relative illumination of margin field achieves 88 %. Besides, there is no transmittance descending caused by material absorption. Push-broom image with fore-optics＇ distortion is simulated. The optical design can be applied in SWIR spectral imagers with wide FOV and enhance system＇s detection sensitivity extremely.
出处
《光学学报》
EI
CAS
CSCD
北大核心
2012年第10期226-231,共6页
Acta Optica Sinica
基金
国家863计划(2011AA7020103)资助课题
