Making lenses

During this week Geoff and myself used the lens blank prepared by Neil Devil to cut a parabolic profile lens. Geoff coded a parabolic curve into the nano-lathe software to generate the .nc file for cutting. We ran a couple of rough passes with the diamond tool to create the curvature of the lens and then optically polished it with a finishing pass. Because we used acrylic, it was much faster than cutting the mirror facets. We completed the top side first and then flipped the lens to cut the other side.

This lens is hopefully the start of our venture into lens making! Geoff and myself are also working with Dr Noelia Martinez Ray to design more accurate curvatures for our lenses. The purpose of this lens is to project an image of the translucent slide so that it focuses just before the surface of the mirror facet.

Translucent image reflected onto the ‘pixelated’ mirror plane.

Both this projected image and the mirror surface are then projected though the objective lens into a combined single image, as per the images I have posted throughout the blog. Below are some images which document the process.

Geoff fixing the flat acrylic disc and jig onto the nano-lathe spindle.
The cut and polished lens still attached to the spindle.
Optical polished lens.
Both sides were cut and polished to crate a bi-convex lens for shorter focal length.
Polished lens sitting in the jig.