Share Email Print

Optical Engineering

Optical method for spatial noise removal in interferometry
Format Member Price Non-Member Price
PDF $20.00 $25.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

We present an analysis of the interference of light scattered from different planes in a simple interferometer, to establish a method that will allow the final output fringe contrast to be enhanced through spatial noise removal. The approach developed involves modifying the spatial coherence of the illuminating wave. By controlling the correlation length of this wave, a time-averaged interferogram along with another for which a ? phase shift has been introduced into the reference arm is shown to provide the information necessary to retrieve the fringe pattern with relatively little noise remaining. The approach suggested allows the controlling parameters to be easily varied optically in order to suppress different spatial noise types and scales. The greatest benefits of this method are in cases where large-scale and slowly varying surfaces or index profiles are to be accurately measured. Simulations are presented and the effectiveness of the proposed coherence degradation procedure is evaluated.

Paper Details

Date Published: 1 April 1996
PDF: 6 pages
Opt. Eng. 35(4) doi: 10.1117/1.600713
Published in: Optical Engineering Volume 35, Issue 4
Show Author Affiliations
Ching-Wei W. Liao, Univ. of Massachusetts/Lowell (United States)
Michael A. Fiddy, Univ. of Massachusetts/Lowell (United States)

© SPIE. Terms of Use
Back to Top