Spatial mode pattern stability with strain for a localized single-ended two-mode fiber optic strain sensor

摘要

rrupt immune technique for the two-mode sensor is designed and developed. Preliminary results indicate a minimum resolution of half of one fringe for a 15 cm gauge length sensor in transmission. Also a new derivation of the phase-strain relationship for a two-mode elliptical core fiber sensor has been carried out which shows an improvement of 5% when compared to the previous models. Finally, a procedure for single-ending and localizing the two-mode sensor is given in detail. A single- ended, localized sensor has been used in a cantilever beam experiment and yields a strain sensitivity of 0.1 rad/$mu$epsilon.m.