PSM Applications

The Point Source Microscope (PSM) is used to locate the apex of retroreflecting prisms in 3 degrees of translational freedom with a precision of less than 1 micron. The process is easily explained for right angle prisms, as will be done in this paper, but the explanation is valid for cube corner retroreflectors such as those mounted in spherical balls, spherically mounted retroreflectors, or SMRs, for use with laser trackers. With suitable, simple fixtures, the measurements for all 3 directions are made to a precision of < 1 μm in less than 1 minute.

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, […]

ABSTRACT  An autostigmatic microscope is described and its uses explained. Then an adaptation of the original instrument is described that uses current technological advances in laser diodes and video displays to turn an old workhorse into a versatile optical test and alignment device. This paper illustrates applications that make use of the capabilities of the […]