Focused-Laser Interferometric Position Sensor

Authors

• Stephen J. Friedman, University of Nebraska - Lincoln
• Brett E. Barwick, University of Nebraska-LincolnFollow
• Herman Batelaan, University of Nebraska - LincolnFollow

ORCID IDs

Herman Batelaan

Document Type

Article

Date of this Version

12-2005

Citation

Review of Scientific Instruments (2005) 76: 123106. DOI: 10.1063/1.2130667.

Comments

Copyright 2005, American Institute of Physics. Used by permission.

Abstract

We describe a simple method to measure the position shifts of an object with a range of tens of micrometers using a focused-laser (FL) interferometric position sensor. In this article we examine the effects of mechanical vibration on FL and Michelson interferometers. We tested both interferometers using vibration amplitudes ranging from 0 to 20 μm. Our FL interferometer has a resolution much better than the diffraction grating periodicities of 10 and 14 μm used in our experiments. A FL interferometer provides improved mechanical stability at the expense of spatial resolution. Our experimental results show that Michelson interferometers cannot be used when the vibration amplitude is more than an optical wavelength. The main purpose of this article is to demonstrate that a focused-laser interferometric position sensor can be used to measure the position shifts of an object on a less sensitive, micrometer scale when the vibration amplitude is too large to use a Michelson interferometer.