Optimal design of the fluorescence sensors based on step-index multimode optical fibers

A fluorescence fiber sensor based on step-index multimode optical fibers is simulated and design by beam propagation method with Beamprop module of Rsoft-CAD software, in the requirement of the much more exciting light in fluorescent material coated on the fiber core. The normalized exciting light power in the coating layer is calculated and analyzed. According to the numerical optimal results, the refractive index n
_o
of fluorescent material layer is 1.49, and the optimal external diameter of coated layer should be greater than 206μm.