Enhanced transmission induced by embedded graphene in periodic, quasiperiodic, and random photonic crystals
Abhishek Padhy, Rahul Bandyopadhyay, Carlos H. Costa, C.G. Bezerra, Chittaranjan Nayak
Abstract
The study of photonic crystals, artificial materials whose dielectric properties can be tailored according to the stacking of their constituents, remains an attractive research field, and it is the basis of photonic devices based on the generation, processing, and storage of photons. In this paper, we employ a transfer-matrix treatment to study the propagation of light waves in periodic, quasiperiodic (Fibonacci, Octonacci, and Dodecanacci), and random dielectric multilayers with graphene embedded. The structures considered here are composed of two building blocks, silicon dioxide (building block <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>A</mml:mi> <mml:mo>=</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">S</mml:mi> <mml:mi mathvariant="normal">i</mml:mi> </mml:mrow> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ) and titanium dioxide (building block <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>B</mml:mi> <mml:mo>=</mml:mo> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">T</mml:mi> <mml:mi mathvariant="normal">i</mml:mi> </mml:mrow> </mml:mrow> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:mi mathvariant="normal">O</mml:mi> </mml:mrow> </mml:mrow> <mml:mn>2</mml:mn> </mml:msub> </mml:mrow> </mml:math> ). We calculate their transmission spectra as a function of incident angle <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>θ</mml:mi> </mml:math> and reduced frequency <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi mathvariant="normal">Ω</mml:mi> </mml:math> . Our main goal is to investigate the enhancement of the transmission due to the presence of graphene. In particular, we show that bandgap regions become passband regions when graphene is embedded in the optical multilayers. More specifically, for a range of the incident angle <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi>θ</mml:mi> </mml:math> and reduced frequency <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:mi mathvariant="normal">Ω</mml:mi> </mml:math> , the PCs with graphene embedded display an unexpected property: the electromagnetic radiation is transmitted mainly through the multilayers and not reflected or absorbed as expected for large structures.