All-optical logic gates have extraordinary application in ultra-high-speed Boolean operation and logical computation. All-optical logic gates like XOR, OR, and NOT using metal–insulator–metal waveguides are proposed here and designed under the footprint of 13 
 $${\upmu}{\text{m}}^{2}$$
 which is smaller than the previously reported work. The device's analysis is performed using the finite-difference time-domain method (FDTD), and results have been verified using MATLAB simulation. The performance parameter, extinction ratio for the proposed device, is computed and obtained 27.80 dB. The suggested logic gates can also be used as major components in optical communication, which leads to the development of a new way for the design of plasmonic integrated circuits.

An optimized design of all-optical XOR, OR, and NOT gates using plasmonic waveguide

Reversible logic gates are capable of designing lossless digital systems, which have received a great deal of attention in photonic integrated circuits due to their advantages, such as less heat generation and low power dissipation. In this paper, all-optical reversible Feynman and Toffoli logic gates are designed for optical computing devices and low-power integrated circuits. Proposed designs of all-optical reversible logic gates are implemented with two-dimensional photonic crystal waveguides without using any nonlinear material. The finite-difference time-domain method is used to simulate and verify the proposed design, and it is operated at a wavelength of 1550 nm. The structure of all-optical reversible logic gates requires much less area, and Feynman logic gates offer a contrast ratio (CR) of 12.4 dB, transmittance of 0.96, and less insertion loss of −0.015dB, while Toffoli logic gates offer a CR of 32.5 dB, transmittance of 0.9, and less insertion loss of −0.04dB.

Design of all-optical reversible logic gates using photonic crystal waveguides for optical computing and photonic integrated circuits.

All-optical logic gates have proven their significance in the digital world for the implementation of high-speed computations. We propose herein a novel structure for an all-optical AND gate using the concept of a power combiner based on a Y-shaped metal–insulator–metal waveguide with a 4 µm × 7 µm footprint. This design works based on the principle of linear interference. The insertion loss and extinction ratio of the design are given as 0.165 and 14.11 dB, respectively. The design is analyzed by using the finite-difference time-domain (FDTD) method and verified using MATLAB. The minimized structure can be used to design any complex logic circuit to achieve better performance in the future.

The design, analysis, and simulation of an optimized all-optical AND gate using a Y-shaped plasmonic waveguide for high-speed computing devices

https://link.springer.com/content/pdf/10.1007/s11082-021-03374-0.pdf

Design and analysis of a photonic crystal-based all-optical 3-input OR gate for high-speed optical processing

We employ seven optical waveguides based on two-dimensional linear photonic crystal (LPhC) to realize an all optical comparator (AOCMP). The proposed 1-bit AOCMP has a very simple structure with a footprint of 356 μm2 which is composed of 31 × 33 cubic lattice of silicon rods immersed in air. This LPhC comparator comprises two input ports and two output ports. The functionality of the proposed 1-bit AOCMP is based on constructive and destructive interference phenomenon of optical beams and phase shift keying technique. The finite difference time domain (FDTD) procedure based on Yee’s Algorithm is used to compute the propagation of optical waves in this structure. The FDTD simulation results of suggested 1-bit AOCMP indicate that the minimum and maximum values of the normalized power at ON and OFF states for output ports are 62% and 10%, respectively. Also, the ON–OFF contrast ratio, bit rate, rise and fall times (Tr and Tf) of the suggested design are about 7.92 dB, 2.22 Tb/S, 0.15 ps and 0.05 ps, respectively. 

/pdf/a-novel-proposal-for-all-optical-1-bit-comparator-based-on-25ds31uh.pdf

A novel proposal for all optical 1-bit comparator based on 2D linear photonic crystal

We propose a photonic crystal-based all-optical AND, OR, and XOR logic gates using square lattice silicon rods with air background. The design of proposed logic gates works on beam interference principle and operates efficiently by changing phase of light beams at 1550 nm wavelength. The proposed AOX logic gates are implemented with only one structure with variations in the phase of applied input signals. Simulation and verification of design are done by using finite-difference time-domain method. The design offers a contrast ratio of 33.05 dB, 10.50 dB, and 8.29 dB of proposed AND, OR, and XOR logic gates correspondingly with optimized refractive index and silicon rod radius values.

Design of all-optical AND, OR, and XOR logic gates using photonic crystals for switching applications

The performance of an ultra-compact all-optical D flip-flop using photonic crystal waveguides is numerically analyzed and examined by optimized parameters such as refractive index and silicon rod radius. In the field of optical networking and computing, flip-flops are used to reduce the complexity of digital circuits. The phenomenon of optical interference effect is used to implement a D flip-flop at a wavelength of 1550 nm. This structure is designed using T-shaped waveguides without using non-linear material. The proposed design is small, has low insertion losses of 0.087 dB when operated at low power level, and provides high contrast ratio of 25 dB and transmission ratio of more than 96%.

Design of all-optical D flip-flop using photonic crystal waveguides for optical computing and networking

This study proposes, designs, and simulates a unique plasmonic Y-shaped MIM waveguide based 2 × 1 multiplexer (MUX) structure utilising opti-FDTD software. Two plasmonic Y-shaped waveguides are positioned facing one another inside a minimum wafer size of 6 µm × 3.5 µm in the 2 × 1 MUX configurations that is being described. The design parameters are adjusted until the plasmonic multiplexer performs as required under optimal conditions. Extinction ratio and insertion loss are two performance metrics that are calculated for performance analysis of the design, which indicate the potential to be applied in plasmonic integrated circuits.

/pdf/an-all-optical-2-x-1-multiplexer-using-a-metal-insulator-3w0tofje.pdf

Venkatrao Palacharla

Papers

Design of all-optical AND, OR, and XOR logic gates using photonic crystals for switching applications

Design of all-optical D flip-flop using photonic crystal waveguides for optical computing and networking

An All Optical 2 × 1 Multiplexer Using a Metal-Insulator-Metal based Plasmonic Waveguide for Processing at a Rapid Pace

A Y-shaped photonic integrated device with XNOR/NAND/NOR for optical signal processing