Tuning dynamic range and sensitivity of white-light, multimode, fiber-optic surface plasmon resonance sensors

This paper presents the advantages of modifying the geometry of the sensing tip of a white-light, multimode optical fiber SPR sensor to optimize the d ynamic range and sensitivity. By selectively beveling the distal end of the fiber probe, the wavelength of resonance can be redshifted by more than 10 0 nm and blue-shifted by more than 30 nm, This increases the flexibility of a white-light SPR sensor by increasing the dynamic range of accessible RIs and by shifting the resonance to the most sensitive regions of the detecto r. Sensitivity, measured in wavelength shift per RI change, can be increase d by a factor of 4, Also, multiple-wavelength regions of SPR activity can s imultaneously be observed on the same probe, thus increasing the informatio n content of a SPR spectrum.