Mode-division and spatial-division optical fiber sensors

The aim of this paper is to provide a comprehensive review mode-division and spatial-division optical fiber sensors, mainly encompassing interferometers advanced gratings. Compared with their single-mode counterparts, which have very mature field many highly successful commercial applications, multimodal configurations developed more recently advances in device fabrication novel mode control devices. Multimodal sensors considerably widen the range possible sensing modalities opportunities for increased accuracy performance conventional applications. Recent progress these areas attested by sharp increases number publications rise technology readiness level. In paper, we first fundamental operating principles such sensors. We then report on theoretical formalism simulation procedures that allow prediction spectral changes response Finally, discuss some recent cutting-edge physical (bio)chemical fields. This provides both step-by-step guide relevant non-specialists entering techniques skilled practitioners.