Adaptive heterodyne photorefractive interferometer for ultrasound detection: optimization and application

Author

Ing, R.K. ; Pouet, B.F. ; Krishnaswamy, S. ; Royer, D.

Author_Institution

Lab. Ondes et Acoust., Paris VII Univ., France

Volume

1

fYear

1997

fDate

5-8 Oct 1997

Firstpage

613

Abstract

The advantages of ultrasonic remote detection using a heterodyne photorefractive interferometer are demonstrated. The speckle nature of the light reflected by a rough surface (or after propagation through a multimode fiber) does not degrade the interferometer sensitivity. Thanks to the process of wave mixing in photorefractive crystals, this interferometer has a large etendue. Furthermore, the heterodyne detection provides an absolute measurement of the ultrasonic amplitudes. We investigate the influence of an applied ac electric field. Two photorefractive crystals, undoped BSO and BSO:Cr, which have different optical characteristics are compared. Finally, examples of application to NDE are demonstrated

Keywords

bismuth compounds; chromium; light interferometers; light interferometry; multiwave mixing; photorefractive effect; photorefractive materials; remote sensing; speckle; ultrasonic materials testing; BSO:Cr; Bi12SiO20:Cr; Bi₁₂SiO₂₀:Cr; adaptive heterodyne photorefractive interferometer; applied alternating current electric field; heterodyne detection; interferometer sensitivity; light; multimode fiber; optical characteristics; photorefractive crystals; propagation; rough surface; speckle nature; ultrasonic amplitudes; ultrasonic remote detection; undoped BSO; wave mixing; Crystals; Optical interferometry; Optical propagation; Optical surface waves; Photorefractive effect; Photorefractive materials; Rough surfaces; Speckle; Surface roughness; Ultrasonic imaging;

fLanguage

English

Publisher

ieee

Conference_Titel

Ultrasonics Symposium, 1997. Proceedings., 1997 IEEE

Conference_Location

Toronto, Ont.

ISSN

1051-0117

Print_ISBN

0-7803-4153-8

Type

conf

DOI

10.1109/ULTSYM.1997.663096

Filename

663096