Applied Physics Letters · 1996 · 121 citations · 0 references
Natural SciencesMaterials EngineeringMaterials ScienceMechanical Behavior Of MaterialsOptical MaterialsOpticsFiber Optic MaterialsFiber OpticsFiber PropertiesOptical FibersRefractive IndexStrain MeasurementDirect Stress MeasurementsFiber Bragg GratingsModulation IndexRefractive Index ChangesRefractive Index DeterminationSingle-mode FibersSingle-mode Optical FibersTension Analysis
The tension on the core of single-mode fibers is strongly increased by the formation of a Bragg grating. This tension increase lowers the refractive index because of the photoelastic effect. On the other hand, the compaction of the core network results in an increased refractive index. The two contributions are evaluated from axial stress measurements, from the determined index modulation amplitude, and from the mean index change of the Bragg gratings. The total Bragg grating index modulation is smaller than the compaction-induced index modulation by 30%–35% because of the photoelastic effect.