High sensitivity surface plasmon resonance sensor based on phase interrogation at optimal incident wavelengths

It is demonstrated that ultrahigh sensitivity of glucose refractive index measurement can be achieved via surface plasmon resonance excitation in which the phase difference between p- and s-polarized reflected waves is monitored as a function of the incident angle. Sensitivity with values down to the order of 10−8 is obtained by performing the measurements at optimal incident wavelengths. This represents an order of magnitude improvement compared to the previously reported values in the literature.