Near-infrared single-mode fiber evanescent fluorosensor

Summary form only given. Fluorescence-based optical fiber sensors respond to spectral changes in light coupled to or from the fiber. In our sensing configuration we utilize evanescent field excitation where a portion of the light traveling in the fiber core penetrates into the surrounding medium with the power of the evanescent field decaying exponentially from the fiber core to the cladding. In our scheme, this evanescent field interacts with dye molecules (excitation/ emission peaks at 785/805 nm respectively) outside the fiber core, yet separated from the fiber surface by a distance smaller than the wavelength of the excitation light. Coupling of sources outside the cladding by this method has been predicted by a wave model of the light.