Jitendra Nath Roy

Integrated all-optical logic and arithmetic operations with the help of a TOAD-based interferometer device--alternative approach

Interferometric devices have drawn a great interest in all-optical signal processing for their high-speed photonic activity. The nonlinear optical loop mirror provides a major support to optical switching based all-optical logic and algebraic operations. The gate based on the terahertz optical asymmetric demultiplexer (TOAD) has added new momentum in this field. Optical tree architecture (OTA) plays a significant role in the optical interconnecting network. We have tried to exploit the advantages of both OTA- and TOAD-based switches. We have proposed a TOAD-based tree architecture, a new and alternative scheme, for integrated all-optical logic and arithmetic operations.

All-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer-based tree architecture

An all-optical arithmetic unit with the help of terahertz-optical-asymmetric-demultiplexer (TOAD)-based tree architecture is proposed. We describe the all-optical arithmetic unit by using a set of all-optical multiplexer, all-optical full-adder, and optical switch. The all-optical arithmetic unit can be used to perform a fast central processor unit using optical hardware components. We have tried to exploit the advantages of both optical tree architecture and TOAD-based switch to design an integrated all-optical circuit that can perform binary addition, addition with carry, subtract with borrow, subtract (2s complement), double, increment, decrement, and transfer operations.

Ultrafast All-Optical Half Adder Using Quantum-Dot Semiconductor Optical Amplifier-Based Mach-Zehnder Interferometer

Interferometric devices have drawn a great interest in all-optical signal processing for their high-speed photonic activity. Quantum-dot semiconductor optical amplifier (QD-SOA)-based gate has added a new momentum in this field to perform all-optical logic and algebraic operations. In this paper, a new and alternative scheme for all-optical half adder using two QD-SOA-based Mach-Zehnder interferometers is theoretically investigated and demonstrated. The proposed scheme is driven by the pair of input data streams for one switch between which the Boolean xor function is to be executed to produce sum-bit. Then the output of the first switch and one of the input data are utilized to drive the second switch to produce carry-bit. The impact of the peak data power as well as of the QD-SOAs current density, small signal gain, and QD-SOAs length on the ER and Q-factor of the switching outcome are explored and assessed by means of numerical simulation. The operation of the system is demonstrated with 160 Gbit/s.

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.

Quaternary Galois field adder based all-optical multivalued logic circuits

Galois field (GF) algebraic expressions have been found to be promising choices for reversible and quantum implementation of multivalued logic. For the first time to our knowledge, we developed GF(4) adder multivalued (four valued) logic circuits in an all-optical domain. The principle and possibilities of an all-optical GF(4) adder circuit are described. The theoretical model is presented and verified through numerical simulation. The quaternary inverter, successor, clockwise cycle, and counterclockwise cycle gates are proposed with the help of the all-optical GF(4) adder circuit. In this scheme different quaternary logical states are represented by different polarized light. A terahertz optical asymmetric demultiplexer interferometric switch plays an important role in this scheme.

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.

An all-optical technique for a binary-to-quaternary encoder and a quaternary-to-binary decoder

A polarization encoded all-optical scheme for a binary-(radix = 2)-to-quaternary (radix = 4) encoder and a quaternary-to-binary decoder is proposed and described. The performance of the proposed circuit is verified through numerical calculation. In this all-optical scheme, the numbers are represented by different discrete polarized states of light. The model is simple, practical and useful for future all-optical information processing.

Terahertz optical asymmetric demultiplexer based tree-net architecture for all-optical conversion scheme from binary to its other 2n radix based form

To exploit the parallelism of optics in data processing, a suitable number system and an efficient encoding/decoding scheme for handling the data are very essential. In the field of optical computing and parallel information processing, several number systems like binary, quaternary, octal, hexadecimal, etc. have been used for different arithmetic and algebraic operations. Here, we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture.

DESIGNING OF ALL-OPTICAL TRI-STATE LOGIC SYSTEM WITH THE HELP OF OPTICAL NONLINEAR MATERIAL

Nonlinear optics has been of increased interest for all-optical signal, data and image processing in high speed photonic networks. The application of multi-valued (nonbinary) digital signals can provide considerable relief in transmission, storage and processing of a large amount of information in digital signal processing. Here, we propose the design of an all-optical system for some basic tri-state logic operations (trinary OR, trinary AND, trinary XOR, Inverter, Truth detector, False detector) which exploits the polarization properties of light. Nonlinear material based optical switch can play an important role. Tri-state logic can play a significant role towards carry and borrow free arithmetic operations. The principles and possibilities of the design of nonlinear material based tri-state logic circuits are proposed and described.

All-optical binary flip-flop with the help of Terahertz Optical Asymmetric Demultiplexer

The memory device is very important as they store various values either temporary or permanently. Optical flip-flop memories form a fundamental building block for all-optical packet switches in the next generation communication networks. All-optical flip-flop memory with the help of Terahertz Optical Asymmetric Demultiplexer (TOAD) is proposed and described. Principles and possibilities of all-optical circuits for TOAD based S–R, J–K, D and T flip-flop are reported. Numerical simulation confirming described method is also given in this paper.