Designing an electro-optical encoder based on photonic crystals using the graphene–Al₂O₃ stacks

Abstract

In this paper, an electro-optical 4-to-2 encoder based on a photonic crystal is presented. The structure is composed of four silicon waveguides, four photonic crystal structures including the graphene– A l 2 O 3 stacks, and two optical combiners. Two one-dimensional arrays of air holes in the silicon background are designed parallel to the waveguides. Also, a graphene– A l 2 O 3 stack is placed at the center of each array, which provides the desired interferences. This feature is used for controlling the optical wave transmission through the waveguides. Using two optical combiners at the end of two waveguides, the received signals from the waveguides will be guided toward the output ports. The amount of the transmitted signal from input ports to the output of the encoder can be controlled by applying the proper chemical potential to the graphene-based stacks. The simulation results show that the encoding operation can be achieved by using 0.2 eV and 0.8 eV for chemical potentials. In addition, the normalized output power margins for logic 0 and 1 are calculated to be 8.2% and 46.7%, respectively. The footprint for the proposed structure is approximately equal to 127 µ m 2 . Also, the required optical power intensity at input ports is 100 m W / µ m 2 .

Design and analysis of photonic crystal ring resonator based 6 × 6 wavelength router for photonic integrated circuits

“…This eventually entails routing of signals between different ports in the integrated circuit networks with complete connectivity and improved performance [2]. Photonic crystalbased components such as splitters [3,4], circulators [5], filters [6], decoder [7], low-power encoders [8][9][10], and routers [11][12][13] were designed and reported. Among them, routers play a vital role in transmitting signals from one user to others with low loss and high efficiency in order to deliver high-quality signals to the end-users and minimise the traffic in the data transmission.…”

A novel design of an all‐optical D flip‐flop based on 2D photonic crystals

“…In the field of Sequential circuits, such as flip Flops, there has been very little work done that has disadvantages, such as dimensions and complexity, that have been tried to eliminate in this paper. [15][16][17][18][19][20][21][22][23][24][25][26][27] Light waves of specific frequencies cannot pass through photonic crystals because of their alternating dielectric structures. There is a term for the frequency range in which light cannot pass through a structure, known as the photonic band gap (PBG).…”

“…Photonic crystals have been used to design combined logic circuit types such as adders, subtractors, coders, decoders, multiplexers, and de‐multiplexers. In the field of Sequential circuits, such as flip Flops, there has been very little work done that has disadvantages, such as dimensions and complexity, that have been tried to eliminate in this paper 15–27 …”

New designs of 4 × 2 photonic crystal encoders using ring resonators

“…According to the phase difference between the CW and CCW signals, the interference could be either constructive or destructive. Researchers proposed different designs for 4 × 2 PhC Encoders, using linear and non-linear materials, and using point defects, line defects, and/or ring resonators (Makvandi et al 2021;Rajasekar et al 2020;Mehdizadeh et al 2017;Chhipa et al 2022;Saranya and Shankar 2021;Latha et al 2022a, b;Arunkumar et al 2022;Fallahi et al 2021;Khatib and Shahi 2020;Saranya and Rajesh 2020;Mostafa et al 2019b), beside using cross-connected waveguides (Haddadan and Soroosh 2019), graphene stack in the center of a photonic crystal for approaching the encoding operation (Haddadan et al 2020).…”