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West Bengal, India

Majumdar P.,Muc Womens College | Samanta S.K.,Visva Bharati
Computers and Mathematics with Applications | Year: 2010

In this paper, we define generalised fuzzy soft sets and study some of their properties. Application of generalised fuzzy soft sets in decision making problem and medical diagnosis problem has been shown. © 2009 Elsevier Ltd. All rights reserved. Source

An all-optical arithmetic and logic unit is the integral part of optical computing and data processing. In this paper, the author proposes a method to develop an all-optical arithmetic and logic unit by means of which so many binary logic operations such as AND, OR, NAND, NOR, EXOR, data comparator etc., as well as some arithmetic operations, such as half-addition, half-subtraction, full-addition, full-subtraction multiplication, etc., can be performed by properly selecting the frequencies of the control signals and using the frequency encoded input data. For this purpose, the author has exploited the frequency conversion scheme of semiconductor optical amplifier (SOA) using nonlinear polarization rotation character of the probe beam in SOA and, cross-gain modulation character of reflecting semiconductor optical amplifier (RSOA). Frequency-dependent optical beam routing to different channels have done using optical add/drop multiplexer made of SOA with multiquantum well structure. Frequency conversion efficiency of SOA and RSOA are very high as well as switching speed of SOA is very fast with very good ON-OFF contrast ratio. © 2006 IEEE. Source

Optical data comparator is the part and parcel of arithmetic and logical unit of any optical data processor and it is working as a building block in a larger optical circuit, as an optical switch in all optical header processing and optical packet switching based all optical telecommunications system. In this article the author proposes a method of developing an all optical single bit comparator unit and subsequently extending the proposal to develop a n-bit comparator exploiting the nonlinear rotation of the state of polarization of the probe beam in semiconductor optical amplifier (SOA). Here the dataset to be compared are taken in frequency encoded/decoded form throughout the communication. The major advantages of frequency encoding over all other conventional techniques are that as the frequency of any signal is fundamental one so it can preserve its identity throughout the communication of optical signal and minimizes the probability of bit error problem. For frequency routing purpose optical add/drop multiplexer (ADM) is used which not only route the pump beams properly but also to amplify the pump beams efficiently. Switching speed of 'MZI-SOA switch' as well as SOA based switches are very fast with good onoff contrast ratio and as a result it is possible to obtain very fast action of optical data comparator. © 2010 Elsevier Ltd. All rights reserved. Source

Garai S.K.,Muc Womens College
Optics Communications | Year: 2014

All optical reversible logic gates have significant applications in the field of optics and optoelectronics for developing different sequential and combinational circuits of optical computing, optical signal processing and in multi-valued logic operations and quantum computing. Here the author proposes a method for developing all optical three-input-output Fredkin gate and modified Fredkin gate using frequency encoded data. For this purpose the author has exploited the properties of efficient frequency conversion and faster switching speed of semiconductor optical amplifiers. Simulation results of the three input-output Fredkin gate testifies to the feasibility of the proposed scheme. These Fredkin gates are universal logic gates, and can be used to develop different all-optical logic and data processors in communication network. © 2013 Elsevier B.V. All rights reserved. Source

Garai S.K.,Muc Womens College
Optics and Laser Technology | Year: 2015

All optical multivalued logic processors are of paramount importance in optical computing and signal processing. In this communication, the author proposes a new method of developing all-optical quaternary logic gates which are the extension of binary logic gates. To develop the quaternary logic gate the authors first coverts the quaternary frequency encoded data into equivalent binary intensity encoded data; then binary logic operations are done among the equivalent binary data, and finally the intensity encoded data outputs are converted into frequency encoded quaternary logic output. Simulation result supports the feasibility of the proposed scheme. Novelty of the scheme is that the same optical circuit is dedicated to implement any two-input quaternary logic operation only by changing two basic switches functioning as binary logic gates. Finally, the authors have cascaded these logic gates using "1 x 2" all-optical switches to develop quaternary logic unit by means of which any kind of quaternary logic operation as proposed in this scheme can be performed. Dense wavelength division demultiplexers (DMUX) are used here for wavelength routing purpose, and switching and frequency conversion characters of semiconductor optical amplifiers are exploited to develop very fast and secure quaternary logic unit. © 2014 Elsevier Ltd. All rights reserved. Source

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