Design and testing of infrared diffractive telescope imaging optical systems

Diffractive telescope is an updated imaging technology, it differs from conventional refractive and reflective imaging system, which is based on the principle of diffraction image. However, one of the great challenges of design this optical system is that the diffractive optical element focuses on different wavelengths of light at different points in space, thereby distorting the color characteristics of image. In this paper, we designs a long-wavelength infrared diffractive telescope imaging system with flat surface Fresnel lens and cancels the infrared optical system chromatic aberration by another flat surface Fresnel lens, achieving broadband light (from 8 mu m to 12 mu m) to a common focus. At last, the diffuse spot size and MTF function provide diffractive-limited performance. (C) 2015 Elsevier GmbH. All rights reserved