Development of a Low-Cost High Accuracy Phase Shifting Gauge Block Interferometer

Abstract

Prohibitive cost of available commercial gauge block interferometers resulted in numerous retrofitting projects in National Measurement Institutes, upgrading old gauge block interferometers to be used with laser sources and digital interferogram acquisition and processing. We demonstrate the possibility of building a new gauge block interferometer using mostly off-the-shelf components, with comparatively low cost and sufficiently high accuracy. Additional advantages over retrofitting are that an open platform for further research is obtained, and that reconfiguration to accommodate various measurement objects other than gauge blocks is possible. In this paper we will present the design of new phase shifting gauge block interferometer built at Croatian National Laboratory for Length, preliminary measurement results, and compare it with a retrofitted Zeiss gauge block interferometer.