Magnetic control of Goos-Hanchen shifts in a yttrium-iron-garnet film

TL;DR

This paper explores how magnetic properties of yttrium-iron-garnet films influence the Goos-Hanchen shifts during reflection and transmission, revealing controllable negative shifts and nonreciprocal effects useful for photonic applications.

Contribution

It demonstrates the magnetic control of Goos-Hanchen shifts in YIG films, including the conditions for negative shifts and the impact of magnetic tuning on shift symmetry.

Findings

Reversal of shift sign by tuning magnetic field, frequency, and incident angle.

Existence of nonreciprocal and slab-thickness-independent shifts.

Analytical and numerical verification of shift behaviors.

Abstract

We investigate the Goos-Hanchen (G-H) shifts reflected and transmitted by a yttrium-iron-garnet (YIG) film for both normal and oblique incidence. It is found that the nonreciprocity effect of the MO material does not only result in a nonvanishing reflected shift at normal incidence, but also leads to a slab-thickness-independent term which breaks the symmetry between the reflected and transmitted shifts at oblique incidence. The asymptotic behaviors of the normal-incidence reflected shift are obtained in the vicinity of two characteristic frequencies corresponding to a minimum reflectivity and a total reflection, respectively. Moreover, the coexistence of two types of negative-reflected-shift (NRS) at oblique incidence is discussed. We show that the reversal of the shifts from positive to negative values can be realized by tuning the magnitude of applied magnetic field, the frequency of incident wave and the slab thickness as well as the incident angle. In addition, we further investigate two special cases for practical purposes: the reflected shift with a total reflection and the transmitted shift with a total transmission. Numerical simulations are also performed to verify our analytical results.