Fringe compensation in multiband speckle shearography using a wedge prism

Claas Falldorf; Steen Gruner Hanson; Wolfgang Osten; Werner P.O. Juptner

doi:10.1117/12.516581

27 May 2003 Fringe compensation in multiband speckle shearography using a wedge prism

Claas Falldorf, Steen Gruner Hanson, Wolfgang Osten, Werner P.O. Juptner

Proceedings Volume 4933, Speckle Metrology 2003; (2003) https://doi.org/10.1117/12.516581
Event: Speckle Metrology 2003, 2003, Trondheim, Norway

Abstract

Using a multiband light source in Speckle Shearography makes dispersion effects become an issue. Since the fringe pattern of a shearographic measurement depends on the wavelength, the fringe modulation decreases if a light source with a very broad band is used. Therefore, in this paper we propose to make the fringe distance of the resulting shearogram independent of the wavelength using a dispersive optical component. To demonstrate this method, a shearing interferometer is presented, which creates a shear that is proportional to the wavelength. Provided that the object deformation along the shear is linear to the first order, the wavelength dependent shear is obtained by inserting a wedge prism into a Michelson Interferometer with the object in the input plane and the detector array in the output plane. An important prerequisite to this technique is that the refractive index of the wedge prism has a linear characteristic within the observed spectral range. Since the experimental investigations were performed with a mercury arc lamp, nBK7 is shown to be a suitable material within the range of 435 nm to 546 nm.

Citation Download Citation

Claas Falldorf, Steen Gruner Hanson, Wolfgang Osten, and Werner P.O. Juptner "Fringe compensation in multiband speckle shearography using a wedge prism", Proc. SPIE 4933, Speckle Metrology 2003, (27 May 2003); https://doi.org/10.1117/12.516581

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