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Reis C.,Telecommunications Institute of Portugal | Parca G.,Telecommunications Institute of Portugal | Bougioukos M.,National Technical University of Athens | Maziotis A.,National Technical University of Athens | And 13 more authors.
Journal of Optical Communications and Networking | Year: 2014

In this paper, we address the experimental implementation of an all-optical packet routing scheme, with contention resolution capability, using interconnected semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer (SOA-MZI) structures. Cross talk stemming from the blocked packets, due to the nonideal switching performed by the SOA-MZIs, is analyzed in every stage of the routing configuration. The routing functions and states performance are evaluated through bit-error ratio measurements and extinction ratio analysis. © 2014 Optical Society of America. Source


Chattopadhyay T.,Kolaghat Thermal Power Station
Applied Optics | Year: 2012

Computing with reversibility is the only way to avoid dissipation of energy associated with bit erase. So, a reversible microprocessor is required for future computing. In this paper, a design of a simple all-optical reversible programmable processor is proposed using a polarizing beam splitter, liquid crystal-phase spatial light modulators, a half-wave plate, and plane mirrors. This circuit can perform 16 logical operations according to three programming inputs. Also, inputs canbe easily recovered from the outputs. Itis named the "reversible programmable Boolean logic unit (RPBLU)." The logic unit is the basic building block of many complex computational operations. Hence the design is important in sense. Two orthogonally polarized lights are defined here as two logical states, respectively. © 2012 Optical Society of America. Source


Chattopadhyay T.,Kolaghat Thermal Power Station | Reis C.,Telecommunications Institute of Portugal | Reis C.,University of Aveiro | Andre P.,Telecommunications Institute of Portugal | And 3 more authors.
Optics Communications | Year: 2012

A novel scheme for an all-optical clocked D flip-flop, with very low complexity, is proposed and numerically demonstrated. This new flip-flop configuration is based on a semiconductor optical amplifier - Mach-Zehnder interferometer (SOA-MZI), with a feedback loop, and presents two stable states determined by the phase shift between the two MZI arms. © 2011 Elsevier B.V. All rights reserved. Source


Chattopadhyay T.,Kolaghat Thermal Power Station | Caulfield H.J.,Fisk University
Mechanical Systems and Signal Processing | Year: 2015

Nothing from nothing gives simple simile, but something from nothing is an interesting and challenging task. Adolf Lohmann once proposed 'do nothing machine' in optics, which only copies input to output. Passive logic module (PALM) is a special type of 'do nothing machine' which can converts inputs into one of 16 possible binary outputs. This logic module is not like the conventional irreversible one. It is a simple type of reversible Turing machine. In this manuscript we discussed and demonstrated PALM using mechanical movement of plane mirrors. Also we discussed the theoretical model of micro electro mechanical system (MEMS) based PALM in this manuscript. It may have several valuable properties such as passive operation (no need for nonlinear elements as other logic device require) and modular logic (one device implementing any Boolean logic function with simple internal changes). The result is obtained from the demonstration by only looking up the output. No calculation is required to get the result. Not only that, PALM is a simple type of the famous 'billiard ball machine', which also discussed in this manuscript. © 2014 Elsevier Ltd. All rights reserved. Source


Reis C.,Telecommunications Institute of Portugal | Maziotis A.,National Technical University of Athens | Kouloumentas C.,National Technical University of Athens | Chattopadhyay T.,Kolaghat Thermal Power Station | And 8 more authors.
Optik | Year: 2013

In this paper, different approaches to implement all-optical flip-flops, working with a synchronization signal, will be presented and compared. In this type of optical bistable devices, the information present at the inputs produces effects on the outputs, throughout all the clock pulse period. The performance of optical clocked flip-flops will be studied in terms of extinction ratio (ER), switching energies and switching times. © 2012 Elsevier GmbH. Source

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