Design of scene simulation optics for dual field angle infrared imagers

The design of the optical systems of simulator for testing of infrared imaging system is described,which has field angle of 6° or 8°.Infrared scene simulator technologies are outlined.The optical systems include projection optics and a variable magnification lens.The lens between the LCD panel and liquid crystal light valve(LCLV) produces visible image at varying magnifications on LCLV.The projection optics collimates infrared image from LCLV to generate infrared scene from infinity.The varying image size meets the need of the test optics.The projection optics is designed for a constant field angle and entrance pupil.Thus image always fills entrance aperture and view field of the test optical system.The effective focal length of the system is about 271.69 mm.There is sufficient exit pupil distance to match simulator exit pupil to the LWIR imagery system entrance pupil.A long working distance between LCLV and simulator ensures the mechanical and the optical assembly.The Modulation Transfer Function(MTF) and the geometric blur spot show the perfect image quality of the projection optics.In contrast with zoom system,the simple optics systems meet the requirements of low cost and high feasibility.