Simultaneous phase measurement interferometry for laser interaction in air

The problem encountered when evaluating phase profile of laser interacted images with direct phase mapping method, using only one interferogram, was in the form of phase ambiguity. This was due the existence of extra fringes in the interacted region of the interferogram. The very sensitive Phase Mea...

Full description

Saved in:

Bibliographic Details
Main Author:	Yahaya, Asiah
Format:	Thesis
Language:	English
Published:	2006
Subjects:	QC Physics
Online Access:	http://eprints.utm.my/id/eprint/1279/1/AsiahYahayaPFS2006.pdf
Tags:	Add Tag No Tags, Be the first to tag this record!

id	my-utm-ep.1279
record_format	uketd_dc
spelling	my-utm-ep.12792018-02-20T02:02:45Z Simultaneous phase measurement interferometry for laser interaction in air 2006-02 Yahaya, Asiah QC Physics The problem encountered when evaluating phase profile of laser interacted images with direct phase mapping method, using only one interferogram, was in the form of phase ambiguity. This was due the existence of extra fringes in the interacted region of the interferogram. The very sensitive Phase Measurement Interferometry (PMI) also suffers from environmental factors such as vibrations and air turbulence. The new system developed to reduce phase ambiguity was a three outputs interferometer, which was designed to capture three interferograms simultaneously. The fast photography incorporated in the system managed to eliminate the problems of vibrations and air turbulence. The three interferogarms were initially arranged to have a phase difference of 90Â° with one another; a requirement for quadrature imaging. Since the interferograms were captured simultaneously, they would carry different phase information of the event. The acoustic wave generated by laser interaction caused the fringes to deviate accordingly to the change in its phase. From their three intensities, appropriate phase shifting algorithms were selected to produce a single final phase change profile of the interaction event. The result obtained revealed a significant contribution to the reduction in phase ambiguity. The changes in phase were associated with the changes in refractive index, density and pressure. The values of pressure change were compared to those obtained from the conventional fringe analysis. Measurements made at time delay of 3.6 Âµs indicated a 26 % difference. As the delay increased, this difference seemed to decrease and at around 5.0 Âµs both techniques seemed to produce agreeable results. The nonlinear profiles of the maximum pressure change with time using the two techniques were presented. Despite the high complexity of the experimental setup, the system managed to fulfill the objectives for its development 2006-02 Thesis http://eprints.utm.my/id/eprint/1279/ http://eprints.utm.my/id/eprint/1279/1/AsiahYahayaPFS2006.pdf application/pdf en public phd doctoral Universiti Teknologi Malaysia, Faculty of Science Faculty of Science
institution	Universiti Teknologi Malaysia
collection	UTM Institutional Repository
language	English
topic	QC Physics
spellingShingle	QC Physics Yahaya, Asiah Simultaneous phase measurement interferometry for laser interaction in air
description	The problem encountered when evaluating phase profile of laser interacted images with direct phase mapping method, using only one interferogram, was in the form of phase ambiguity. This was due the existence of extra fringes in the interacted region of the interferogram. The very sensitive Phase Measurement Interferometry (PMI) also suffers from environmental factors such as vibrations and air turbulence. The new system developed to reduce phase ambiguity was a three outputs interferometer, which was designed to capture three interferograms simultaneously. The fast photography incorporated in the system managed to eliminate the problems of vibrations and air turbulence. The three interferogarms were initially arranged to have a phase difference of 90Â° with one another; a requirement for quadrature imaging. Since the interferograms were captured simultaneously, they would carry different phase information of the event. The acoustic wave generated by laser interaction caused the fringes to deviate accordingly to the change in its phase. From their three intensities, appropriate phase shifting algorithms were selected to produce a single final phase change profile of the interaction event. The result obtained revealed a significant contribution to the reduction in phase ambiguity. The changes in phase were associated with the changes in refractive index, density and pressure. The values of pressure change were compared to those obtained from the conventional fringe analysis. Measurements made at time delay of 3.6 Âµs indicated a 26 % difference. As the delay increased, this difference seemed to decrease and at around 5.0 Âµs both techniques seemed to produce agreeable results. The nonlinear profiles of the maximum pressure change with time using the two techniques were presented. Despite the high complexity of the experimental setup, the system managed to fulfill the objectives for its development
format	Thesis
qualification_name	Doctor of Philosophy (PhD.)
qualification_level	Doctorate
author	Yahaya, Asiah
author_facet	Yahaya, Asiah
author_sort	Yahaya, Asiah
title	Simultaneous phase measurement interferometry for laser interaction in air
title_short	Simultaneous phase measurement interferometry for laser interaction in air
title_full	Simultaneous phase measurement interferometry for laser interaction in air
title_fullStr	Simultaneous phase measurement interferometry for laser interaction in air
title_full_unstemmed	Simultaneous phase measurement interferometry for laser interaction in air
title_sort	simultaneous phase measurement interferometry for laser interaction in air
granting_institution	Universiti Teknologi Malaysia, Faculty of Science
granting_department	Faculty of Science
publishDate	2006
url	http://eprints.utm.my/id/eprint/1279/1/AsiahYahayaPFS2006.pdf
_version_	1747814372262019072

Simultaneous phase measurement interferometry for laser interaction in air

Similar Items