Pratik Dutta

All optical implementation of Mach-Zehnder interferometer based reversible sequential circuit

In this work, we present all optical reversible implementation of Flip-Flops using semiconductor optical amplifier (SOA) based Mach-Zehnder interferometer (MZI) switches. Improved design of MZI-based functionally reversible RS, D, JK, T and three different implementations of all optical functionally reversible MZI-based Master-Slave Flip-Flop using RS, D and JK Flip-Flop are presented. Detailed analysis and design complexities of all the functionally reversible optical Flip-Flops with improved optical costs have been reported.

All Optical Implementation of Mach-Zehnder Interferometer Based Reversible Sequential Counters

This work presents all optical reversible implementation of sequential counters using semiconductor optical amplifier (SOA) based Mach-Zehnder interferometer (MZI) switches. All the designs are implemented using minimum number of MZI switches and garbage outputs. This design ensures improved optical costs in reversible realization of all the counter circuits. The theoretical model is simulated to verify the functionality of the circuits. Design complexity of all the proposed memory elements has been analyzed.

Role of Carbon Capture and Storage in Meeting the Climate Mitigation Target

Scientific studies over the years have clearly indicated warming of global climate due to rising concentration of anthropogenic greenhouse gas emissions. Continued emissions are certain to lead to catastrophic consequence. Deliberating on this very important issue of sustainability of the entire earth for a long period, the global community finally reached consensus during the Paris Climate Agreement in 2015 to limit the temperature rise to 2 °C by 2050 and even try to achieve a lower temperature rise. Amongst other options like adoption of renewables on a much larger scale, fuel switching, and increasing power system efficiency; carbon capture and storage is perceived to be another feasible option for meeting this global climate mitigation target. Carbon capture and storage (CCS) essentially means chemically capturing CO2 from power plants running on fossil fuels, especially coal, transport and then store it permanently in some geological formation beneath the earth. As per the estimate of International Energy Agency, 12% of the total greenhouse gas emissions totaling about 94 Gt of cumulative CO2 emissions have to be stored into the subsurface geological formations up to 2050. Considerable research and development work backed by experience gained through demonstration and commercial projects, the technology is mature now. Although the first CCS project commenced operation more than twenty years back, the progress has been slow over the years due to many techno-economical factors and other policy issues. However, in the recent years, there has been significant progress in actual deployment of the technology with more than 21 large-scale running projects and projects under advanced construction. Furthermore, a number of projects are in the pipeline. The total installed capacity of all these projects is approximately 70 Mt of CO2 per year. Although CCS is a proven technology now, notwithstanding the recent growth in deployment, the rate of adoption is still not in track to meet the global target set for 2050.

A Boolean Expression based Template Matching Technique for Optical Circuit Generation

With the increased need of high speed computing paradigm, the optical circuits are gaining more importance. Immense investigations are under progress to build full-fledge optical circuits with minimum hardware. In this work, we are showing a template matching scheme that generates low cost optical circuits using Mach-Zehnder Interferometers (MZI) based optical devices. In this proposed design, initially we design four optimized templates using MZIs and later these templates perform exhaustive search in boolean logic expression to find its structural matches. If a match is found then it replaces the corresponding sub-circuit with its own template. Experimental results are provided and a comparative analysis is made with recently reported works. It has been found that the proposed scheme not only reduces the optical cost of a circuit but also brings down the total optical device utilization in the circuit.

Mach-Zehnder Interferometer Based All Optical Reversible Carry-Lookahead Adder

In this work, we present an efficient reversible implementation of Carry-Lookahead Adder (CLA) in all-optical domain. Now-a-days, semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (MZI) plays a vital role in the field of ultra-fast all-optical signal processing. We have used all optical based Mach-Zehnder Interferometer (MZI) switches to design the CLA circuit implementing reversible functionality. Two approaches are proposed for designing the CLA circuit. First, we propose a hierarchical approach for implementation of 2n-bit reversible CLA. In the second approach, we remove the drawback of hierarchical CLA and improve the design by implementing non-modular staircase structure of n-bit reversible CLA. The design complexities of both the approaches are computed. Experimental result shows that the optical cost and delay incurred in staircase structured reversible implementation of CLA are much less than those proposed in the recently reported works.