Abstract
Hetero-core optical fiber can detect various chemical phenomena on the sensing part where evanescent
waves are generated. These waves interact with the chemicals on the surface, propagating light spectra
changes. When dye is adsorbed, the propagating light spectra resemble the transmitted spectra of the
chemicals. In addition, the interaction between evanescent waves and metal thin film or metal nanoparticles
prepared on the sensing part respectively causes a surface plasmon resonance and a localized surface
plasmon resonance. These sensors detect the refractive index changes caused by a binding reaction on
the surface. This review describes chemical sensors that utilize hetero-core optical fibers.
