Compact Lightweight Freeform GRIN Optics for Small Arms Fire Control

Freeform GRIN optics will be developed for fire-control systems. In the Phase I effort, 1) a 36-mm F/4 freeform GRIN objective optic with a half field of view no less than 4 degrees, and 2) a 20-diopter freeform GRIN Alvarez optical pair will be designed, fabricated, and optimized for achromatic performance over the 390-nm to 700-nm spectral range. The lens performance will be assessed by measuring wavefront and chromatic distortion, monochromatic and polychromatic spot diagrams, ray fans, modulation transfer function, and field curvature, and comparing the measurements to the modeled performance. In the Phase I option, the 36-mm F/4 GRIN objective lens will be configured with the Alvarez lenses, with a motorized controller, and a prototype variable-magnification (1x to 5x) scope optic will be demonstrated. The optical performance of the system will be characterized, and the benefits of the technology compared to conventional glass optics will be quantified. In Phase II, a gun-hardened scope optic will be optimized, field tested, and live-fire tested.