Dalai Gowri Sankar Rao

Bio: Dalai Gowri Sankar Rao is an academic researcher from DIT University. The author has contributed to research in topics: Photonic crystal & Optical computing. The author has an hindex of 3, co-authored 5 publications receiving 25 citations.

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

Abstract: 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 D flip-flop using photonic crystal waveguides for optical computing and networking

Abstract: 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 reversible logic gates using photonic crystal waveguides for optical computing and photonic integrated circuits.

Abstract: 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 and optimization of all-optical demultiplexer using photonic crystals for optical computing applications

Abstract: In this work, photonic crystal (PhC) based all-optical 1 × 2 demultiplexer is designed for optical computing and optical signal processing. The structure is implemented with two-dimensional PhCs using T-shaped waveguides with an optimized silicon rod radius of 0.2a. Performance of the proposed structure is verified and analyzed by using the finite-difference time-domain method. The design of all-optical demultiplexer is operated based on optical interference effect at a wavelength of 1550 nm. Proposed design occupies less area of 8.4 × 5.4 µm, provides a contrast ratio of 18.53 dB, 94.52% of minimum and 100% of maximum transmission ratio and it has less insertion loss of 0.017 dB; therefore, the proposed device is suitable for photonic integrated devices.

Design and simulation of a 2 × 1 All-Optical multiplexer based on photonic crystals

Abstract: • A new design for optical multiplexer has been proposed based on photonic crystals. • A small structure is used for the proposed optical 2 × 1 multiplexer. • The simplicity of the structure makes it suitable for optically integrated circuits. Photonic crystals are alternating structures widely used to design various types of logic circuits. In this paper, a 2 × 1 multiplexer is designed and simulated based on two-dimensional photonic crystals with a cubic lattice. Silicon rods in the air were used to design this multiplexer. Only linear defects were considered in the design of the structure. In other words, none of the rods were changed and all Si rods were the same, which is one of the advantages of this structure. Optical sources with a wavelength of 1.55 µm were utilized in the inputs and select line. The size of the structure was 12.16 µm × 12.16 µm. The small dimension and the simplicity of the structure make it a suitable candidate in optically integrated circuits.

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

Abstract: 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.

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

Abstract: 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.

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

Abstract: 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.