Analytical sensitivity and reflected power through a D-shape optical fibre sensor

Abstract

In this paper, the reflection properties and sensitivity of a D-shape optical fibre sensor are investigated theoretically and numerically with the emphasis on the metal layer [gold (Au), silver (Ag), copper (Cu), and aluminum (Al)]. Maxwell’s equations are used to determine the electric and magnetic fields of the incident waves at each layer. Snell’s law is applied and the boundary conditions are imposed at each layer interface to calculate the reflected power and sensitivity of the sensor. In the numerical results, the mentioned power is computed and illustrated as a function of wavelength, angle of incidence, metal layer thickness and refractive index of the external medium when the metal layer changes. The variation of sensitivity with the wavelength of the incident radiations is also proposed for some of the given metals.

Performance analysis of optical fiber surface plasmon resonance sensor in single-mode operation region

“…The power reflection coefficient or reflectivity R ′ of the structure for a single reflection is then [18,21]…”

“…If the number of reflections within the sensor of length l is m , the total reflectivity R can be expressed as [18,21]…”

“…To the best of our knowledge, no prior studies related to single-mode fiber SPR sensors (such as in [8] and [18][19][20][21][22]) have examined the effect of changing the value of the operating wavelength, while keeping the condition for single-mode operation, on the sensitivity of the SPR sensor.…”