Squeezed Carrier Interferogram for Wavelet Phase Recovery

Vamara Dembele,Abdel Karim Nassim,Faial Alaoui,Khalid Assid

doi:10.5923/j.optics.20120204.02

Abstract

The purpose of the present work is the use of the Phase evaluation CWT algorith m to extract the phase from squeezing interferogram. The squeezing interfero metry technique generates a spatial carrier interferogram named squeezed interferogram by numerical co mbination of M shifted fringes patterns. The M shifted fringes patterns are digitally generated fro m co mb ination of t wo π/2 shifted fringe patterns. Fro m squeezed interferogram the phase is extracted in wavelet domain using CWT algorith m which leads directly to the phase distribution without the complex step of phase unwrapping. Simu lated fringe pattern are used to test our technique and real fringe pattern are used to improve the accuracy of this technique.

Highlights

Many whole field optical techniques provide the measurement data encoded as the phase of a periodic intensity profile
To illustrate the use of our method for real applications, we tested its performance on a rough ground finish, alu min iu m surface fro m a hard disk drive assembly
Changes were induced by tilting the surface and recording interferograms before and after

Summary

Introduction

Many whole field optical techniques provide the measurement data encoded as the phase of a periodic intensity profile. The obtained image is called a fringe pattern. The fringe pattern analysis generally consists of the phase evaluation methods[1, 2] employed to measure various physical magnitudes in variety of scientific and engineering fie lds. A high potential accuracy is attained when the carrier frequency value is conveniently selected[11]. It is not evident to have such a value, especially for experimental fringe patterns. The aim of this work is to determine optical phase distribution from spatial carrier interferogram named squeezed interferogram in the wavelet do main. Sev eral techniques have been used successfully in fringe pattern d emo d u lat ion [13]. In t h is pap er we p rop os e t o use

Objectives

Results

Conclusion