1. INTRODUCTION Spherically mounted retroreflectors (SMRs) are an essential part of spatial metrology when using a laser tracker. However, the precision of the laser tracker measurement is no better than the precision with which the cube corner retroreflector is mounted in the spherical ball. Thus measuring the position of the apex of the cube corner […]
1. INTRODUCTION The premise of this paper is that the only remaining way to improve optical system performance is with better alignment techniques. We feel optical design is a mature field and that little can be done to improve the design of optical systems by improvements to lens design software. The software may become easier […]
1. INTRODUCTION Finding the optical axis of an aspheric surface is an essential part of making an aspheric lens because the center of curvature, or optical axis, of the second side must lie on, or be coincident with, respectively, the optical axis of the first side for maximum optical performance. Looking at the center of […]
1. INTRODUCTION It is common to think of computer generated holograms (CGH) as artifacts for testing aspheres but they can also be used as general calibration artifacts and fixtures for the alignment and test other more conventional optics. We show how simple Fresnel zone patterns can be created to simulate centers of curvature or axes […]
Introduction Need for reverse engineering Properties needed to reverse engineer Measurements needed Measurements that can be made Center thickness Rear Radius Back focal length No closed form solution for unknowns Spreadsheet example N, t and r2 were estimated and a, b and c calculated Solver used to minimize lower right hand cell to give calculated n, t […]
INTRODUCTION On-machine metrology is particularly important for diamond turning and grinding as it is difficult to remount and align a part if it does not meet off-line inspection criteria. There is also the issue of tool wear; a process that started well may fail part way through the cut, and if tool replacement is needed, […]