Algorithm for optical characterization of dielectric gradient index nanofilm by surface plasmon resonance spectroscopy

A numerical algorithm for determining the refractive index profiles of gradient nanofilms is proposed. A physical justification for the necessity of using spectroscopic measurements in surface plasmon resonance sensing in addition to angular measurements for the unambiguous reconstruction of the shape of the gradient refractive index profile is given. The proposed approach can be effective for nanofilms made of dielectric materials transparent in the IR and THz range.