Lookup NU author(s): Dr Zhongxu Hu,
Dr John Hedley,
Dr Barry Gallacher,
Dr Isabel Arce-Garcia
This paper reports on utilizing Raman spectroscopy to characterize the motion and measure strain levels in dynamic micromechanical structures. The main advantages of such a technique is that surface features are not required to characterize the 3D motion as the crystal lattice is used as the reference frame and that it is suited to high frequency measurements. Two methodologies are presented. The first utilizes a strobed diode laser probe beam with the centre position of the Raman peak giving a measure of strain as a function of phase. A measurement resolution of 210 mu strain is obtained at frequencies up to 100 kHz. The second method uses a HeNe laser probe beam with the broadening of the Raman peak, indicating strain levels. Although no phase data are available in the latter technique, the technique is rapid and may be utilized on a Raman system without any modification. A measurement resolution of 30 mu strain is achieved and strain mapping of a region may be performed within minutes. As strobing is not used here, the technique is not frequency limited. Comparisons with alternative optical characterization techniques are made.
Author(s): Hu ZX, Hedley J, Gallacher BJ, Arce-Garcia I
Publication type: Article
Publication status: Published
Journal: Journal of Micromechanics and Microengineering
Date deposited: 28/03/2011
ISSN (print): 0960-1317
ISSN (electronic): 1361-6439
Publisher: Institute of Physics Publishing Ltd.
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