Spectral interferometry for surface plasmon resonance sensing of
aqueous solutions
Jiˇr´ı Luˇna´ cˇ ek1 , Petr Hlubina1 , Dalibor Ciprian1 , Michaela Duliakov´a1 , and
Milena Luˇna´ cˇ kov´a2
1 Department
ˇ - Technical University of Ostrava, 17. listopadu 15, Ostrava
of Physics, VSB
708 33, Czech Republic
2 Department of Mathematics and Descriptive Geometry, VSB
ˇ - Technical University of
Ostrava, 17. listopadu 15, Ostrava 708 33, Czech Republic
This paper deals with a polarimetric setup to measure the refractive index change of aqueous solutions. The experimental method is based on surface plasmon resonance (SPR) in
Kretschmann configuration combined with spectral interferometry. The experimental setup
consists of a white-light source, a linear polarizer, a birefringent quartz crystal, a SF10 coupling prism covered by a gold layer (thickness 44 nm) and a linear analyzer. The angle of
incidence is approximately 60 degrees. The attenuated total reflection at the prism base serves
for the excitation of surface plasmon waves (SPWs). The output spectral interference signals
affected by the SPWs are recorded by a spectrometer [1]. In order to calculate SPR-induced
differential phase change, a windowed Fourier transform (WFT) [2] was adopted to extract
the phases from two spectral interferograms, one corresponding to the reference material (air)
and the second to the analyte (NaCl aqueous solution). The shift of phase curve is related to
the analyte refractive index change.
The refractive index of the NaCl aqueous solutions (0, 2 and 5 percent) was measured
by the Abbe refractometer at a wavelength of 589.3 nm and compared with theoretical one,
calculated by the Lorentz-Lorenz equation [3]. The resonance wavelengths as extremes of
the SPR-induced differential phase changes retrieved from spectral interference signals were
compared with the resonance wavelengths determined from spectral reflectance measurements [4]. A good agreement between the values was confirmed. Comparison of the experimental dependencies with the theoretical ones will be a subject of a subsequent work.
This work was supported by the grants No. P102/11/0675 and CZ.1.05/2.1.00/01.0040
[1] J. Luˇna´ cˇ ek, P. Hlubina, M. Lesˇna´ k, D. Ciprian, M. Luˇna´ cˇ kov´a, Adv. Sci. Eng. Med. 5,
(2013) 577.
[2] P. Hlubina, J. Luˇna´ cˇ ek, D. Ciprian, R. Chlebus, Opt. Commun., 281 (2008) 2349.
[3] M. Born, E. Wolf, Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light (7th ed.), Cambridge University Press (1999).
[4] P. Hlubina, D. Ciprian, J. Luˇna´ cˇ ek, Opt. Lett., 34 (2009) 2661.

Spectral interferometry for surface plasmon resonance sensing of