Wavefront coding technique for controlling thermal defocus aberration in an infrared imaging system.

We use a wavefront coding approach to control thermal defocus aberration in an IR imaging system. The design method of athermalized system using a wavefront coding technique is discussed. An athermalized long wave IR optical system, which works at temperatures ranging from -40 °C to 60 °C, is designed by employing a cubic phase mask. Computer simulations and the first experimental demonstration are executed to verify the performance of this wavefront coded athermalized system and to clarify the issues related to its implementation.