The Design of a Hybrid Diffractive-Refractive Wide-Angle Eyepiece with a Large Exit Pupil Distance

The diffractive optical elements, with the negative dispersive characteristic and the random phase distributing to realize random phase modulation for wave-front, are not only helpful to simplify the optical system, but also improve the image quality, while putting it into the optical system. It can decrease the element numbers of the system and obtain a compact configuration that introducing diffractive optical element into the design of eyepiece. A hybrid diffractive-refractive wide-angle eyepiece, with a big exit pupil distance, is designed by using the Code V Optical Design Software. The features of the wide-angle eyepiece are 30mm effective focal length, 60°whole field-of-view (FOV), 30mm exit pupil distance and 6mm exit pupil diameter, and which consists of four lens and two diffractive elements. From the result of design, the MTF in the center field of the wide-angle eyepiece is over 0.55at 60lp/mm, at the same time, the MTFs in all fields are over 0.3 at 50lp/mm, which show that this wide-angle eyepiece has a great image quality.