Controlling Fringe Sensitivity of Electro-Optic Holography Systems Using Laser Diode Current Modulation

Bybee, Shannon J

ISBN 10: 128891105X / ISBN 13: 9781288911059

Published by Biblioscholar, 2013

About this Item

PRINT ON DEMAND pp. 152.

Seller Inventory # 18390601371

Bibliographic Details

• Title: Controlling Fringe Sensitivity of Electro-Optic Holography Systems Using Laser Diode Current Modulation
• Publisher: Biblioscholar
• Publication Date: 2013
• Language: English
• ISBN 10: 128891105X
• ISBN 13: 9781288911059
• Binding: Soft cover
• Condition: New

About this title

Synopsis

Electro-Optic Holography (EOH) is a non-intrusive, laser-based, displacement measurement technique capable of static and dynamic displacement measurements. EOH is an optical interference technique in which fringe patterns that represent displacement contour maps are generated. At excessively large displacements the fringe density may be so great that individual fringes are not resolvable using typical EOH techniques. This thesis focuses on the development and implementation of a method for controlling the sensitivity of the EOH system. This method is known as Frequency Translated Electro-Optic Holography (FTEOH). It was determined that by modulating the current source of the laser diode at integer multiples of the object vibration, the fringe pattern is governed by higher order Bessel function of the first kind and the number of fringes that represent a given displacement can be controlled. The reduction of fringes is theoretically unlimited but physically limited by the frequency bandwidth of the signal generator, providing modulation to the laser diode. Although this research technique has been verified theoretically and experimentally in this thesis, due to the current laser diode capabilities it is a tedious and time consuming process to acquire data using the FTEOH technique.