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1
Reflection Shifts in a Graphene-coated Dielectric-Metal
Composite of Non-spherical Particles
Maryam Zoghi
*
University of Tehran, College of Engineering, School of Engineering Science, Enqelab Street, Tehran, Iran,
Postal Code: 11155-4563
Abstract. Using effective medium theory, spatial and angular Goos-Hanchen and Imbert-Fedorov reflection
shifts of a graphene-coated granular substrate composed of non-spherical gold nanoparticles in a dielectric host
are investigated. The numerical results indicate that the composite substrate can play a role in tunability of shifts
similar to that of an electrically-controlled graphene layer does. It is realized that both shape and volume
fraction of granular inclusions can bring about a broad shift modulation. This may provide applications in nano-
optics as well as in characterizing the parameters of the composite.
Keywords: Goos-Hanchen shift, Imbert-Fedorov shift, Graphene, Dielectric-Metal Nanocomposite, Non-
spherical particles, Nano optics.
* E-mail: maryam.zoghi@ut.ac.ir
1 Introduction
The behavior of plane waves in reflection is predicted by geometric optics. Unlike the plane
waves, a finite beam of light bouncing an interface undergoes spatial and angular shifts due to
diffractive corrections. This effect that was first confirmed in experiment by Goos and
Hanchen in 1947 [1] has received great attention during the last decade. A large number of
theoretical and experimental works have been devoted to the study of the Goos-Hanchen
(GH) shift in e.g. non-absorbing [2], weakly absorbing [3], grounded slab [4], and
metasurfaces [5]. Generally, it is desirable to attain large and tunable shift in most practical
cases [6]. Beam shifts have potential applications in the design of optical devices such as
optical waveguide switch [7], optical sensors [8], precision metrology and spin photonics [9].
It is known that shifts are sensitive to the configuration and to the materials constituting the
interface. At a single dielectric interface, the lateral shift is usually small, almost comparable
to the wavelength of incident beam. The shift is demonstrated to be small in metal reflections
as well [10]. However, large positive and negative lateral shifts could be achieved by exciting
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