Achromatic infrared night vision device optical system

The utility model discloses an athermalization infrared night vision device optical system, which comprises a lens assembly, a receiving mechanism and a protection mechanism, the lens assembly is used for light transmission, the receiving mechanism is used for receiving light passing through the lens assembly, and the protection mechanism is arranged between the lens assembly and the receiving mechanism. The lens assembly comprises a first lens, a second lens and a third lens, the second lens is arranged on the back of the first lens, and the third lens is arranged on the back of the second lens. According to the utility model, the first lens, the second lens and the third lens are utilized to form a Petzval structure which is a positive focal power lens, focal power can be reasonably distributed between a front group and a rear group, a high-refractive-index infrared material is selected, and a field curvature can be controlled within a focal depth range by correcting a scattered equilibrium primary field cu