Ultra-fast tunable optoelectronic half adder/subtractor based on photonic crystal ring resonators covered by graphene nanoshells

• Published in: Optical and quantum electronics Vol. 53; no. 7
• Main Authors: Naghizade, saleh, Saghaei, Hamed
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.07.2021; Springer Nature B.V
• Subjects: Absorption spectra; Adding circuits; Characterization and Evaluation of Materials; Chemical potential; Circuit design; Communication networks; Computer Communication Networks; Crystal structure; Electrical Engineering; Finite difference time domain method; Graphene; Integrated circuits; Lasers; Logic circuits; Maxwell's equations; Optical communication; Optical Devices; Optics; Optoelectronics; Photonic crystals; Photonics; Physical properties; Physics; Physics and Astronomy; Plane waves; Resonators; Rods; Signal processing; Silicon dioxide; Time domain analysis; Time response; Two dimensional materials; Finite-difference time-domain method; Plane wave expansion method; Ring resonator; Nonlinear material; Optical Kerr effect; Optoelectronic half adder/subtractor; Photonic crystal microstructure
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-021-03071-y

This paper reports a new design of a tunable optoelectronic half adder/subtractor. Two photonic crystal (PhC) ring resonators are used to realize the proposed structure. Several silicon rods surrounded by silica rods covered with graphene nanoshells (GNSs) form every PhC ring resonator. Setting the chemical potential of GNS with an appropriate gate voltage, we can tune the PhC resonant mode as desired. The plane wave expansion technique is used to study the photonic band structure of the fundamental PC microstructure, and the finite-difference time-domain method is employed in the final design for solving Maxwell's equations to analyze the light propagation inside the structure. We systematically study the effects of physical parameters on the transmission reflection and absorption spectra. By optimizing the geometric dimensions, resonant absorption peaks can be excited at the same time for GNSs. Our numerical results also reveal the maximum time response is about 0.8 ps. The 200 µm 2 area of the proposed half adder/subtractor makes it the building block of every photonic integrated circuit. Also, the design of various fast signal processing systems in optical communication networks is possible due to using tunable GNSs in PhC ring resonators. This study can introduce the use of two-dimensional materials in the design and implementation of logic circuits.