Fresnel Collimator?

thingiverse

Crafting a lens from a squashed sphere, then carefully slicing it into a basic Fresnel lens configuration, requires precision. To achieve optical clarity close to perfection, the 3D print would serve as a starting point for creating a silicone release mold. The actual lens would be cast in resin using this mold, yielding a clearer image than expected. Now that the idea is out there, it's up to you to figure out the rest of the process.