Reflection-based fibre-optic refractive index sensor using surface plasmon resonance

Reflection-based fibre-optic refractive index sensor using surface plasmon resonance

Blog Article

A reflection-based fibre-optic refractive index sensor using surface plasmon resonance (SPR) in a thin metal 36" Induction Cooktop film sputtered on a bare core of a multimode optical fibre is presented.The sensing element of the SPR fibre-optic sensor is the core of a step-index optical fibre made of fused silica with a gold film double-sided sputtered on the whole core surface, including the core end face.Consequently, a terminated reflection-based sensing scheme to measure the refractive indices of liquids is realized.

The sensing scheme uses a wavelength interrogation method and the refractive index of a #5.5 MAHOGANY liquid is sensed by measuring the position of the dip in the reflected spectral intensity distribution.As an example, the aqueous solutions of ethanol with refractive indices in a range from 1.333 to 1.

363 are measured.In addition, the increase in the sensitivity of the SPR fibre-optic refractive index sensor with the decrease of the fibre sensing length is demonstrated.