Study on infrared athermal defocusing amount test system

As athermal design is an important issue in the field of infrared optical system design, this paper originated a test procedure on athermal design effect based on optical transfer function gauge. In this procedure, we let the optical system under test automatically focus first, then record its focus position under different temperatures, finally get the relative defocusing amount of the optical system under test under different temperature. This paper also developed a test system of a kind of athermal design effect, introduced its system composition and its working principle of measuring the defocusing amount, and gave the experiment results. The results suggest that it can focus fast, its repeatability is good, and it can resist noise interference with high precision.