<title>Simplified phase-shifting holographic interferometry</title>

Abstract

Phase shifting techniques are often used to increase the precision of measurements made by holographic interferometry. These techniques use dual reference beams whose relative phase can be controlled precisely during reconstruction, usually through the use of piezoelectric transducers, tilting plates, or liquid crystal devices. This paper presents a simplified phase shifting technique which relies only on a standard micrometer screw translation table. Besides its simplicity, this technique also has the advantage of being light efficient. Many dual reference beam interferometers waste half the laser power in the reference beam splitter; this arrangement eliminates that waste. Results of a study in which this phase stepping technique was used in combination with a multi-pass holographic interferometer to measure the energy transferred from a spark to the surroundings gases are presented.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.