1. A Lamb Wave Lens for Acoustic Microscopy
- Author
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Hayrettin Koymen, Abdullah Atalar, Fahrettin Levent Degertekin, Atalar, Abdullah, Köymen, Hayrettin, and Değertekin, F. Levent
- Subjects
Lens (geometry) ,Microscope ,Materials science ,Acoustic imaging ,Design ,Acoustics and Ultrasonics ,Acoustics ,Ray acoustics ,Acoustic microscopy ,Signal ,Scanning acoustic microscope ,law.invention ,Lamb waves ,Optics ,law ,Nondestructive testing ,Acoustic microscopes ,Electrical and Electronic Engineering ,Instrumentation ,Focusing ,Lenses ,business.industry ,Materials characterization ,Lamb wave lens ,Acoustic wave ,Microscopic examination ,business - Abstract
In a conventional scanning acoustic microscope the excited leaky modes contributes significantly to the high contrast obtained in the images. However, all such modes exist simultaneously, and the interpretation of the images is not straightforward, especially in layered media. A new lens geometry is proposed that can be used with acoustic microscopes to image layered solid structures. This new lens can focus the acoustic waves in only one of the Lamb wave modes of the layered solid with a high efficiency. V(Z) curves obtained from this lens are more sensitive to material properties compared to that obtained from conventional lens. Measuring the return signal as a function of frequency results in another characteristic curve, V(f). The Lamb wave lens and the associated characterization methods for the layered structures are described. The results presented show that the Lamb wave lens is at least an order of magnitude more sensitive than the conventional lens and can differentiate between a good bond and a disbond in a layered structure easily. © 1992 IEEE
- Published
- 1992