The attenuation and dispersion of intense stress waves in solids can be measured by fiber optic techniques. This paper describes an in-situ optical fiber strain sensor that can be used to measure transient subsurface strains with a bandwidth of 1 GHz. The sensor consist of a length of polarization maintaining fiber which is illuminated by a coherent polarized light source. The presence of a stress wave is detected and measured by monitoring the state of polarization and phase of the transmitted light, in a manner closely analogous to a classical photoelastic diagnostic-except on a sub-miniature scale. By using two wave-lengths, both components of transverse stress in an incident disturbance can be determined. Experimental results are shown and the sensor principles and measurement techniques are discussed.

Date Published: 23 March 1988
PDF: 9 pages
Proc. SPIE 0838, Fiber Optic and Laser Sensors V, (23 March 1988);

Published in SPIE Proceedings Vol. 0838:
Fiber Optic and Laser Sensors V
Ramon P. DePaula; Eric Udd, Editor(s)