The invention relates to the technical field of
infrared optics, in particular to a large-area-array long-rear-working-distance
infrared optical
system which comprises a head cover, a first lens, a second lens, a third lens, a fourth lens and a
detector, the head cover serves as an optical window, the specific surface curvature
radius and thickness design of the head cover optimizes the light incidence and preliminary convergence effect, and the
light intensity is improved. The structure of the four lenses is reasonably distributed according to positive and negative focal powers to form a stable optical structure, and the
diffraction surface design of the first lens can effectively correct
chromatic aberration and improve the
imaging quality. Meanwhile, the second emergent surface, the third incident surface, the fourth emergent surface and the fifth incident surface all adopt aspheric surface design, aberration is further reduced, and high-resolution imaging of the large-area-array
detector is guaranteed. In addition, through reasonable spacing arrangement between the elements, the long rear working distance of the
system is realized, and the requirements of adapting to detectors of different models are met. In conclusion, the
system successfully realizes an imaging target with a large area array and a long rear working distance.