  Recently, we showed that dielectric mesoscale spheres support super-resonance
effect, i.e. high-order Mie resonance modes with giant field enhancement. The
presence of the surrounding medium leads to a significant influence in the
intensity of the electric and magnetic fields in the particle. In this paper,
we show that this effect can be used for highly precise control of the
effective refractive index of a medium, such as water. We show that a change in
the water temperature by dT=0.0106 C (or the effective refractive index of the
medium by 2e-6) leads to a twofold drop in electric field intensity. All the
presented results are strictly within the framework of the classical Mie theory
without any modifications. A detailed study of the ranges of values of the size
parameters of a spherical particle of the order of 10, which had previously
been neglected, made it possible to reveal a new, unusual physics of the
phenomenon.
