Development of Spiral Grinding Process Technology for Glass Lens Hole Machining

We propose a process technology that can be applied to a variety of applications by machining existing lenses to create an optical system required for research by modifying commercial glass optical systems. A 1-in. hole was created in an LF5 glass lens by drilling, followed by spiral grinding, and finally, precision spiral grinding. In addition, cracking and chipping were analyzed according to the processing process and optimized process conditions. We fabricated an achromatic doublet lens with a diameter of 50.8 mm, focal fa of 75 mm and fba of 65.7 mm, under optimized processing conditions. The processed lenses were determined by measuring the surface geometry of the lenses using ASI, and the lenses were inspected internally using OCT and dark field measurements to verify the internal sectional cracks and chipping of the lenses. The results confirm that there are no problems with the use of the hole in the existing glass lens as an optics. In addition, the manufactured lens will be available as an integrated optical system that can combine lenses with mirrors or detectors to create small systems and multi-axial views.