Abstract

Optical fiber interferometer sensors utilizing phase shifts due to physical perturbations, such as temperature, pressure, and strain, are being developed for applications requiring high sensitivity and immunity from electrical noise.¹ Ultimate sensitivity is obtained by the Mach-Zehnder arrangement using two single-mode fibers. In practice, however, there is some difficulty in packaging and compacting due to the requirements for splitting and recoupling the two optical paths. Multimode fiber employing differential phase shifts among modes was found to be a simple interferometric sensor without a beam splitter and coupler²; but multimode fiber sensors suffer from mode conversion and ambiguous polarization.

© 1983 Optical Society of America