  This paper aims to study the reflection characteristics of optical beams in a
hybrid graphene-hexagonal Boron Nitride (hBN)-graphene structure, which has
been located on SiO2-Si layers. An analytical model is presented to derive the
reflection characteristics by using the transfer matrix method. The upper
Reststrahlen band has been chosen as the studied frequency range. It is shown
that the characteristics of the reflected beam can be effectively controlled by
varying the chemical potential of graphene sheets. The obtained results
represent a high value of the reflected group delay (=15.3 ps) at the frequency
of 24.9 THz. The presented investigation will be helpful to control the group
delays of reflected beams and can be utilized for the design of innovative
graphene-hBN devices in the mid-infrared wavelengths.
