Design of a compact athermalized infrared seeker

Abstract:

In order to meet the application requirement of a certain long wavelength infrared (LWIR) seeker, a small volume, light weight and passively athermalized infrared (IR) objective is designed in this paper. The two-lens telephoto structure is adopted by merely using aluminum alloy as the housing material. By balancing the thermo-optical coefficient and thermal expansion coefficient of materials, an athermalized IR seeker with effective focal length of 90 mm and F number of 1.2 is achieved. The whole optical length is 75 mm, and the weight is only 234 g. The objective can remain fine imaging quality under temperature range from −40°C to 60 °C, which is beneficial to the lightweight design of IR seekers. This work has been supported by the National Natural Science Foundation of China (Nos.11372309 and 61304017), and the Knowledge Innova- tion Program of the Chinese Academy of Sciences (No.YYYJ-1122). E-mail:[e-mail]