Optical fiber modal domain methods which use mode-mode interference as the sensing mechanism have been used to detect strain, temperature and pressure. Typically, bending-induced strain applications involve mode coupling which changes the mode field distributions. In this paper, we report the use of axial strain with minimal bending on a few-mode optical fiber ( V = 4.47) to study mode pattern modulation. Such modulation due to quasi-statically varying strain in particular has been observed and quantified. More complicated low frequency strain variations about "quiescent DC strain" points associated with different system strain sensitivities have also been analyzed. A heuristic discussion of the modal domain phenomenon responsible for this fiber waveguide modal behavior is presented.

Date Published: 23 March 1988
PDF: 4 pages
Proc. SPIE 0838, Fiber Optic and Laser Sensors V, (23 March 1988); doi: 10.1117/12.942538

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