一种像旋扫描变焦红外光学系统

摘要

Based on the principle of optical offsetting image rotator, image rotator scan is studied to expand the optical system Field of View (FOV). An optical design model is introduced, which is a triple imaging zoom structure, and Pechan prism is used as a one-dimension scan component. Moreover, the active athermalization technology is used to satisfy the imaging quality in different temperature. The optical design result is given. The system uses a 480¯6 linear array detector of long wavelength infrared (7.7~10.3μm), the detector length is 12.29 mm, and the F# is 2.6. The detector is tilted and decentered to match the cold stop, and the image rotator scan makes the model have a circular FOV whose radius is the detector length and the system FOV is 4.4º/17.6º with 320/80 mm focal length. The system has 9 lenses with 3 aspheric surfaces, and has near diffraction limited imaging quality in whole FOV.%基于光学消像旋原理，研究了通过像旋扫描以扩大光学系统视场的途径，并建立了一个设计模型。该模型是一个三次成像的变焦结构，采用了别汉棱镜作为一维扫描器件，为保证不同温度时的成像质量，使用了主动消热差技术。系统采用了480×6的线阵长波红外(7.7~10.3μm)探测器，F数为2.6，线阵长度为12.29 mm，通过像旋扫描获得了半径为探测器线阵长度的圆形总视场，并采用倾斜和偏心探测器的方法实现了冷光阑匹配，其视场为4.4º/17.6º，对应焦距为320/80 mm。系统除别汉棱镜外采用了九片透镜，其中3个非球面。系统在全视场范围内具有接近衍射限的像质。