Sourangshu Mukhopadhyay

All-optical method for the addition of binary data by nonlinear materials

An all-optical system for the addition of binary numbers is proposed in which input binary digits are encoded by appropriate cells in two different planes and output binary digits are expressed as the presence (=1) or the absence (=0) of a light signal. The intensity-based optical XOR and AND logic operations are used here as basic building blocks. Nonlinear materials, appropriate cells (pixels), and other conventional optics are utilized in this system.

An optical conversion system: From binary to decimal and decimal to binary

Abstract In optical computing systems both binary and decimal numbers are used for different arithmetical manipulations. Therefore the conversion from binary to decimal and decimal to binary is very important. In this paper these conversion processes are proposed using tree structures, where the channels in the tree are selected either optically or optoelectronically.

Binary optical arithmetic operation scheme with tree architecture by proper accommodation of optical nonlinear materials

Arithmetic operation is an essential task in any type of computing system. In high-speed all-optical computations, arithmetic operations are used to exploit the highest capability of optical performance. We propose a binary addition and subtraction scheme with proper accommodation of optical nonlinear materials. It is also shown that this circuit can perform these operations with the inherent parallelism of optics.

Tree-net architecture for integrated all-optical arithmetic operations and data comparison scheme with optical nonlinear material

In the field of optical interconnecting network the tree architecture has already taken the significant roles. Nonlinear optics has drawn a great interest in all-optical signal processing for its high speed photonic activity. Optical nonlinear materials (ONLM) may provide a major support to optical switching-based all-optical logic and algebraic operations. Here operational speed is extremely high (far above GHz). In this paper, an ONLM-based switching system is extensively used to design tree architecture for developing some arithmetic operational system in an all-optical domain. An alternative scheme of all-optical addition and subtraction and comparison of binary data is also proposed exploiting the above optical tree.

A minimization scheme of optical space-variant logical operations in a combinational architecture

A lot of work on optical logical operations has been reported by scientists and technologists for the last few decades. Optical space-variant logical operations by spatial cellular encoding techniques have also taken a major step in this regard. The present authors here propose an optical process which parallel accommodates all the possible logical operations in a reduced and compact space. This combinational architecture can be extended to the multiple instruction multiple data (MIMD) based optical processors.

Binary optical data subtraction by using a ternary dibit representation technique in optical arithmetic problems

A new ternary dibit representation technique is proposed for a bitwise binary optical data subtraction process.

Alternative approach of conducting phase-modulated all-optical logic gates

It is well established that optical devices and components are more advantageous than their electronic counterparts because of inherent parallelism in optics. Basically electronics are found to be very unsuitable in high speed (above gigahertz) data processing systems whereas tremendous operational speed (in the range of terahertz) can be achieved with the help of optics. The parallelism of optics and the properties of low loss transmission make optics a powerful technology for digital computing and processing and in long-range communications. Again it is well established that logic gates are the basic building blocks of any computing or data processing system. Therefore, any optical data processor needs suitable optically run logic gates. A method of conducting phase-modulated all-optical logic gates is proposed. Here we will exploit the advantages of phase modulation not only in processing but also in encoding as well decoding also.

Parity Checking and Generating Circuit with Nonlinear Material in All-Optical Domain

An all-optical parity checker and parity bit generator circuit is proposed, in which optical non-linear materials are used as switching devices. High-speed (above GHz) logic operations can be achieved by this all-optical circuit that is tremendously fast than its equivalent electronic counterpart. Here these circuits are used to check the errors in optical data through a transmission line.

Effects of Slip on Unsteady Mixed Convective Flow and Heat Transfer Past a Stretching Surface

Unsteady mixed convective boundary layer flow and heat transfer over a stretching vertical surface in the presence of slip are investigated. It is noted that fluid velocity decreases due to the increasing velocity slip parameter resulting in an increase in the temperature field. The rate of heat transfer decreases with the velocity slip parameter while it increases with unsteadiness parameter. The same feature is also noticed for thermal slip parameter.

An All-Optical R-S Flip-Flop by Optical Non-Linear Material

In optical parallel computation the super fast switching speed is very much expected from the switching devices within the computer architecture. Several approaches were proposed in last few decades around the world where uses of non-liner and photo-refractive materials were seen massively in the purpose of developing switching devices. By the proper use of non-linear material logical operations (like NAND, AND, NOT, EX-OR gate) can be performed. These operations are all optical in nature. In this paper such an optical system is proposed which is capable to follow the truth table of a R-S flip-flop. Optical NAND and NOT gate are used here as basic building block.