Gradient index eyepiece technology for head-mounted display applications

Eyepieces used in full color head-mounted displays require a high degree achromatization to exhibit the level of performance required by observers. Many times, this leads to the use of dense glass materials and multi-element systems. The advent of new gradient index material systems as part of the DARPA-sponsored Manufacturable Gradient Index Optics (M-GRIN) may yield new design degrees of freedom for eyepiece and HMD designers. New plastic material systems may be used to simplify eyepiece design and shorten the eyepiece overall length, pulling the entire HMD system closer to the observer's head and improving systems center of gravity. This paper will examine the possibility of using large aperture GRIN optics to achromatize an eyepiece and reduce its overall mass. Assumptions about the material system (index of refraction (n) and delta n) and a candidate full color microdisplay will be clearly stated and may not reflect any commercially available system.