Additive-subtractive speckle interferometry: phase measurements in noisy conditions

Lewis S. Wang; Sridhar Krishnaswamy

doi:10.1117/12.212666

23 June 1995 Additive-subtractive speckle interferometry: phase measurements in noisy conditions

Lewis S. Wang, Sridhar Krishnaswamy

Proceedings Volume 2545, Interferometry VII: Applications; (1995) https://doi.org/10.1117/12.212666
Event: SPIE's 1995 International Symposium on Optical Science, Engineering, and Instrumentation, 1995, San Diego, CA, United States

Abstract

In this paper, we propose a novel technique for quantitative phase measurements of vibrating structures based on additive-subtractive speckle interferometry. Additive fringe patterns (of poor visibility) corresponding to the object deformation are obtained by pulsing the laser illumination at times when the deformation is at its maximum and minimum amplitudes. A relative inter-pulse phase shift is introduced within each repetitive deformation cycle (e.g. +(pi) /2 for the maximum and -(pi) /2 for the minimum amplitudes respectively) to obtain two consecutive conjugate pairs of phase-shifted additive fringe patterns. Additionally, and inter-frame phase shift is introduced between the conjugate pairs of additive fringe patterns, which are then subtracted and rectified to provide a phase-shifted additive-subtractive fringe pattern of good visibility. Typically four such phase-shifted additive-subtractive fringe patterns with relative phase shift of (pi) /2 between each other are obtained, and these are used to calculate the deformation phase map from which the vibration measurement of a circular membrane. The ability of the technique to perform in relatively severe noisy environments is demonstrated.

Citation Download Citation

Lewis S. Wang and Sridhar Krishnaswamy "Additive-subtractive speckle interferometry: phase measurements in noisy conditions", Proc. SPIE 2545, Interferometry VII: Applications, (23 June 1995); https://doi.org/10.1117/12.212666

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available